New asyncRunner

2013-04-20 01:14:20 +01:00 · 2013-04-20 01:14:20 +01:00 · 2177785ca5
commit 2177785ca5
parent 51ba5930af
13 changed files with 1251 additions and 1176 deletions
--- a/index.html
+++ b/index.html
@ -64,7 +64,7 @@
 						<li class="dropdown-submenu"><a href="#"><i
 								class="icon-gdrive"></i> Google Drive</a>
 							<ul class="dropdown-menu">
-								<li><a href="#" class="action-download-gdrive">Import
+								<li><a href="#" class="action-sync-import-gdrive">Import
 										from Google Drive</a></li>
 								<li><a href="#" data-toggle="modal"
 									data-target="#modal-upload-gdrive" class="action-reset-input">Export
@ -73,7 +73,7 @@
 						<li class="dropdown-submenu"><a href="#"><i
 								class="icon-dropbox"></i> Dropbox</a>
 							<ul class="dropdown-menu">
-								<li><a class="action-download-dropbox" href="#">Import
+								<li><a class="action-sync-import-dropbox" href="#">Import
 										from Dropbox</a></li>
 								<li><a href="#" data-toggle="modal"
 									data-target="#modal-upload-dropbox" class="action-reset-input">Export
@ -86,12 +86,14 @@
 						<li class="dropdown-submenu"><a href="#"><i
 								class="icon-share"></i> Publish on</a>
 							<ul class="dropdown-menu">
-                                <li><a href="#" class="action-publish-blogger"><i
-                                        class="icon-blogger"></i> Blogger</a></li>
-                                <li><a href="#" class="action-publish-dropbox"><i
-                                        class="icon-dropbox"></i> Dropbox</a></li>
+								<li><a href="#" class="action-publish-blogger"><i
+										class="icon-blogger"></i> Blogger</a></li>
+								<li><a href="#" class="action-publish-dropbox"><i
+										class="icon-dropbox"></i> Dropbox</a></li>
 								<li><a href="#" class="action-publish-github"><i
 										class="icon-github"></i> GitHub</a></li>
+								<li><a href="#" class="action-publish-gdrive"><i
+										class="icon-gdrive"></i> Google Drive</a></li>
 							</ul></li>
 						<li><a href="#" data-toggle="modal"
 							data-target="#modal-manage-publish" class="action-reset-input"><i
@ -182,7 +184,7 @@
 		<div class="modal-header">
 			<button type="button" class="close" data-dismiss="modal"
 				aria-hidden="true">&times;</button>
-			<h3>Export</h3>
+			<h3>Google Drive export</h3>
 		</div>
 		<div class="modal-body">
 			<p>This will upload the current document into your Google Drive
@ -193,7 +195,7 @@
 		<div class="modal-footer">
 			<a href="#" class="btn" data-dismiss="modal">Cancel</a> <a href="#"
 				data-dismiss="modal"
-				class="btn btn-primary action-upload-gdrive-root">OK</a>
+				class="btn btn-primary action-sync-export-gdrive">OK</a>
 		</div>
 	</div>

@ -201,7 +203,7 @@
 		<div class="modal-header">
 			<button type="button" class="close" data-dismiss="modal"
 				aria-hidden="true">&times;</button>
-			<h3>Export</h3>
+			<h3>Dropbox export</h3>
 		</div>
 		<div class="modal-body">
 			<p>This will upload the current document to your Dropbox account
@ -210,7 +212,7 @@
 			</p>
 			<div class="input-prepend">
 				<span class="add-on"><i class="icon-dropbox"></i></span><input
-					id="upload-dropbox-path" type="text" class="span5"
+					id="input-sync-export-dropbox-path" type="text" class="span5"
 					placeholder="/path/to/My Document.md"></input>
 			</div>
 			<br /> <br /> <b class="muted">NOTE:</b>
@ -223,7 +225,7 @@
 		</div>
 		<div class="modal-footer">
 			<a href="#" class="btn" data-dismiss="modal">Cancel</a> <a href="#"
-				data-dismiss="modal" class="btn btn-primary action-upload-dropbox">OK</a>
+				data-dismiss="modal" class="btn btn-primary action-sync-export-dropbox">OK</a>
 		</div>
 	</div>

@ -246,16 +248,16 @@
 			<p>Add a synchronized location manually:</p>
 			<div class="input-prepend input-append">
 				<span class="add-on" title="Google Drive"><i
-					class="icon-gdrive"></i></span><input id="manual-gdrive-fileid"
+					class="icon-gdrive"></i></span><input id="input-sync-manual-gdrive-id"
 					type="text" class="span5" placeholder="Google Drive file ID"></input>
-				<a class="btn action-manual-gdrive" title="Add location"
+				<a class="btn action-sync-manual-gdrive" title="Add location"
 					data-dismiss="modal"><i class="icon-ok"></i></a>
 			</div>
 			<div class="input-prepend input-append">
 				<span class="add-on" title="Dropbox"><i class="icon-dropbox"></i></span><input
-					id="manual-dropbox-path" type="text" class="span5"
+					id="input-sync-manual-dropbox-path" type="text" class="span5"
 					placeholder="Dropbox file path"></input> <a
-					class="btn action-manual-dropbox" title="Add location"
+					class="btn action-sync-manual-dropbox" title="Add location"
 					data-dismiss="modal"><i class="icon-ok"></i></a>
 			</div>
 			<p class="muted"><b>NOTE:</b> Adding a synchronized location will
@ -271,7 +273,9 @@
 		<div class="modal-header">
 			<button type="button" class="close" data-dismiss="modal"
 				aria-hidden="true">&times;</button>
-			<h3>Publish on <span class="publish-provider-name"></span></h3>
+			<h3>
+				Publish on <span class="publish-provider-name"></span>
+			</h3>
 		</div>
 		<div class="modal-body">
 			<div class="form-horizontal">
@ -314,12 +318,29 @@
 					</div>
 				</div>
 				<div class="control-group modal-publish-dropbox">
-					<label class="control-label" for="input-publish-dropbox-path">File path</label>
+					<label class="control-label" for="input-publish-dropbox-path">File
+						path</label>
 					<div class="controls">
 						<input type="text" id="input-publish-dropbox-path"
 							placeholder="/path/to/My Document.html">
 					</div>
 				</div>
+				<div class="control-group modal-publish-gdrive">
+					<label class="control-label" for="input-publish-gdrive-fileid">File
+						ID (optional)</label>
+					<div class="controls">
+						<input type="text" id="input-publish-gdrive-fileid"
+							placeholder="File ID">
+					</div>
+				</div>
+				<div class="control-group modal-publish-gdrive">
+					<div class="controls muted">
+                        <b>NOTE:</b> If no file ID
+                    is supplied, the file will be created into your Google Drive root
+                    folder. You can move the file within Google Drive afterwards.
+					</div>
+				</div>
+				
 				<div class="control-group">
 					<div class="control-label">Format</div>
 					<div class="controls">
--- a/js/async-runner.js
+++ b/js/async-runner.js
@ -1,121 +1,185 @@
 /**
- *  Used to run asynchronous tasks sequentially (ajax mainly)
- *  An asynchronous task must be created with:
- *  - a required run() function that may call success(), error() or retry()
- *  - an optional onSuccess() function
- *  - an optional onError() function
- *  - an optional timeout field (default is 30000)
+ * Used to run asynchronous tasks sequentially (ajax mainly) An asynchronous
+ * task is composed of different callback types: onRun, onSuccess, onError
 */
-define(["underscore"], function() {
+define([ "underscore" ], function() {

-	var asyncTaskRunner = {};
+	var asyncRunner = {};

 	// Dependencies
 	var core = undefined;

-	var asyncTaskQueue = [];
+	var taskQueue = [];
 	var currentTask = undefined;
 	var currentTaskRunning = false;
 	var currentTaskStartTime = 0;

-	// Run the next task in the queue if any and no other is running
+	asyncRunner.createTask = function() {
+		var task = {};
+		task.finished = false;
+		task.timeout = ASYNC_TASK_DEFAULT_TIMEOUT;
+		task.retryCounter = 0;
+		/**
+		 * onRun callbacks are called by chain(). These callbacks have to call
+		 * chain() themselves to chain with next callback or to finish the task
+		 * and call onSuccess callbacks.
+		 */
+		// Run callbacks
+		task.runCallbacks = [];
+		task.onRun = function(callback) {
+			task.runCallbacks.push(callback);
+		};
+		/**
+		 * onSuccess callbacks are called when every onRun callbacks have
+		 * succeed.
+		 */
+		task.successCallbacks = [];
+		task.onSuccess = function(callback) {
+			task.successCallbacks.push(callback);
+		};
+		/**
+		 * onError callbacks are called when error() is called in a onRun
+		 * callback.
+		 */
+		task.errorCallbacks = [];
+		task.onError = function(callback) {
+			task.errorCallbacks.push(callback);
+		};
+		/**
+		 * chain() calls the next onRun callback or the onSuccess callbacks when
+		 * finished. The optional callback parameter can be used to add a onRun
+		 * callback during execution.
+		 */
+		task.chain = function(callback) {
+			if (task.finished === true) {
+				return;
+			}
+			// If first execution
+			if (task.queue === undefined) {
+				// Create a copy of the onRun callbacks
+				task.queue = task.runCallbacks.slice();
+			}
+			// If a callback is passed as a parameter
+			if(callback !== undefined) {
+				callback();
+				return;
+			}
+			// If all callbacks have been run
+			if (task.queue.length === 0) {
+				// Run the onSuccess callbacks
+				runSafe(task, task.successCallbacks);
+				return;
+			}
+			// Run the next callback
+			var runCallback = task.queue.shift();
+			runCallback();
+		};
+		/**
+		 * error() calls the onError callbacks.
+		 */
+		task.error = function(error) {
+			if (task.finished === true) {
+				return;
+			}
+			error = error || "Unknown error";
+			runSafe(task, task.errorCallbacks, error);
+			// Exit the current call stack
+			throw error;
+		};
+		/**
+		 * retry() can be called in an onRun callback to restart the task
+		 */
+		task.retry = function() {
+			if (task.finished === true) {
+				return;
+			}
+			task.queue = undefined;
+			if (task.retryCounter === 5) {
+				task.error(new Error("Maximum retry number reached"));
+				return;
+			}
+			// Implement an exponential backoff
+			var delay = Math.pow(2, task.retryCounter++) * 1000;
+			currentTaskStartTime = core.currentTime + delay;
+			currentTaskRunning = false;
+			asyncRunner.runTask();
+		};
+		return task;
+	};
+
+	// Run the next task in the queue if any and no other running
 	function runTask() {

 		// If there is a task currently running
-		if(currentTaskRunning === true) {
+		if (currentTaskRunning === true) {
 			// If the current task takes too long
-			var timeout = currentTask.timeout || ASYNC_TASK_DEFAULT_TIMEOUT;
-			if(currentTaskStartTime + timeout < core.currentTime) {
-				currentTask.error();
+			if (currentTaskStartTime + currentTask.timeout < core.currentTime) {
+				var errorMsg = "A timeout occurred.";
+				core.showError(errorMsg);
+				currentTask.error(new Error(errorMsg));
 			}
 			return;
 		}

-		if(currentTask === undefined) {
+		if (currentTask === undefined) {
 			// If no task in the queue
-			if(asyncTaskQueue.length === 0) {
+			if (taskQueue.length === 0) {
 				return;
 			}

 			// Dequeue an enqueued task
-			currentTask = asyncTaskQueue.shift();
+			currentTask = taskQueue.shift();
 			currentTaskStartTime = core.currentTime;
 			core.showWorkingIndicator(true);
-			
-			// Set task attributes and functions
-			currentTask.finished = false;
-			currentTask.retryCounter = 0;
-			currentTask.success = function() {
-				runSafe(this.onSuccess);
-			};
-			currentTask.error = function() {
-				runSafe(this.onError);
-			};
-			currentTask.retry = function() {
-				if(this.finished === true) {
-					return;
-				}
-				if(currentTask.retryCounter === 5) {
-					this.error();
-					return;
-				}
-				// Implement an exponential backoff
-				var delay = Math.pow(2, currentTask.retryCounter++) * 1000;
-				currentTaskStartTime = core.currentTime + delay;
-				currentTaskRunning = false;
-				asyncTaskRunner.runTask();
-			};
 		}

 		// Run the task
-		if(currentTaskStartTime <= core.currentTime) {
+		if (currentTaskStartTime <= core.currentTime) {
 			currentTaskRunning = true;
-			currentTask.run();
+			currentTask.chain();
 		}
 	}

-	asyncTaskRunner.runTask = function() {		
+	asyncRunner.runTask = function() {
 		// Use defer to avoid stack overflow
 		_.defer(runTask);
 	};

-	function runSafe(func) {
-		if(currentTask === undefined || currentTask.finished === true) {
-			return;
-		}
+	function runSafe(task, callbacks, param) {
 		try {
-			if(func) {
-				func();
-			}
+			_.each(callbacks, function(callback) {
+				callback(param);
+			});
 		} finally {
-			currentTask.finished = true;
-			currentTask = undefined;
-			currentTaskRunning = false;
-			if(asyncTaskQueue.length === 0) {
-				core.showWorkingIndicator(false);
+			task.finished = true;
+			if (currentTask === task) {
+				currentTask = undefined;
+				currentTaskRunning = false;
 			}
-			else {
-				asyncTaskRunner.runTask();
+			if (taskQueue.length === 0) {
+				core.showWorkingIndicator(false);
+			} else {
+				asyncRunner.runTask();
 			}
 		}
 	}

-	// Add a task into the queue
-	asyncTaskRunner.addTask = function(asyncTask) {
-		asyncTaskQueue.push(asyncTask);
-		asyncTaskRunner.runTask();
+	// Add a task to the queue
+	asyncRunner.addTask = function(task) {
+		taskQueue.push(task);
+		asyncRunner.runTask();
 	};

 	// Change current task timeout
-	asyncTaskRunner.setCurrentTaskTimeout = function(timeout) {
-		if(currentTask !== undefined) {
+	asyncRunner.setCurrentTaskTimeout = function(timeout) {
+		if (currentTask !== undefined) {
 			currentTask.timeout = timeout;
 		}
 	};

-	asyncTaskRunner.init = function(coreModule) {
+	asyncRunner.init = function(coreModule) {
 		core = coreModule;
 	};

-	return asyncTaskRunner;
+	return asyncRunner;
 });
--- a/js/blogger-provider.js
+++ b/js/blogger-provider.js
@ -13,9 +13,9 @@ define(["jquery", "google-helper"], function($, googleHelper) {
 	bloggerProvider.publish = function(publishAttributes, title, content, callback) {
 		googleHelper.uploadBlogger(publishAttributes.blogUrl,
 			publishAttributes.blogId, publishAttributes.postId, title, content,
-			function(blogId, postId) {
-			if(blogId === undefined || postId === undefined) {
-				callback(true);
+			function(error, blogId, postId) {
+			if(error) {
+				callback(error);
 				return;
 			}
 			publishAttributes.blogId = blogId;
@ -27,10 +27,7 @@ define(["jquery", "google-helper"], function($, googleHelper) {
 	bloggerProvider.newPublishAttributes = function(event) {
 		var publishAttributes = {};
 		publishAttributes.blogUrl = core.getInputValue($("#input-publish-blogger-url"), event);
-		var postId = $("#input-publish-blogger-postid").val();
-		if(postId) {
-			publishAttributes.postId = postId;
-		}
+		publishAttributes.postId = $("#input-publish-blogger-postid").val() || undefined;
 		if(event.isPropagationStopped()) {
 			return undefined;
 		}
--- a/js/config.js
+++ b/js/config.js
@ -9,14 +9,16 @@ var GDRIVE_DEFAULT_FILE_TITLE = "New Markdown document";
 var CHECK_ONLINE_PERIOD = 60000;
 var AJAX_TIMEOUT = 10000;
 var ASYNC_TASK_DEFAULT_TIMEOUT = 30000;
-var AUTH_POPUP_TIMEOUT = 90000;
+var ASYNC_TASK_LONG_TIMEOUT = 90000;
 var SYNC_PERIOD = 180000;
 var USER_IDLE_THRESHOLD = 300000;
 var SYNC_PROVIDER_GDRIVE = "sync.gdrive.";
 var SYNC_PROVIDER_DROPBOX = "sync.dropbox.";
-var PROVIDER_TYPE_PUBLISH_FLAG = 1;
+var PROVIDER_TYPE_SYNC_FLAG = 1;
+var PROVIDER_TYPE_PUBLISH_FLAG = 2;
 var PROVIDER_BLOGGER = "blogger";
 var PROVIDER_DROPBOX = "dropbox";
+var PROVIDER_GDRIVE = "gdrive";
 var PROVIDER_GITHUB = "github";

 // Use by Google's client.js
--- a/js/core.js
+++ b/js/core.js
@ -4,7 +4,7 @@ define(
 		"bootstrap", "jgrowl", "layout", "Markdown.Editor", "config",
 		"underscore" ],
 	function($, fileManager, googleHelper, dropboxHelper, githubHelper,
-		synchronizer, publisher, asyncTaskRunner) {
+		synchronizer, publisher, asyncRunner) {
 	
 	var core = {};
 	
@ -102,7 +102,7 @@ define(
 		$(".modal input[type=text]:not([disabled])").val("");
 	};

-	// Used by asyncTaskRunner
+	// Used by asyncRunner
 	core.showWorkingIndicator = function(show) {
 		if (show === false) {
 			$(".working-indicator").addClass("hide");
@ -115,6 +115,9 @@ define(

 	// Used to show a notification message
 	core.showMessage = function(msg, iconClass, options) {
+		if(!msg) {
+			return;
+		}
 		options = options || {};
 		iconClass = iconClass || "icon-info-sign";
 		$.jGrowl("<i class='icon-white " + iconClass + "'></i> " + _.escape(msg), options);
@ -466,7 +469,7 @@ define(
 	function setupLocalStorage() {
 		if (localStorage["file.list"] === undefined) {
 			localStorage["file.list"] = ";";
-			localStorage["version"] = "v1";
+			localStorage["version"] = "v2";
 		}		
 	}

@ -482,22 +485,53 @@ define(
 			localStorage.removeItem("sync.current");
 			localStorage.removeItem("file.counter");			
 			
-			var fileIndexList = localStorage["file.list"].split(";");
-			for ( var i = 1; i < fileIndexList.length - 1; i++) {
-				var fileIndex = fileIndexList[i];
+			var fileIndexList = _.compact(localStorage["file.list"].split(";"));
+			_.each(fileIndexList, function(fileIndex) {
 				localStorage[fileIndex + ".publish"] = ";";
-				var fileSyncIndexList = localStorage[fileIndex + ".sync"].split(";");
-				for ( var j = 1; j < fileSyncIndexList.length - 1; j++) {
-					var fileSyncIndex = fileSyncIndexList[j];
+				var fileSyncIndexList = _.compact(localStorage[fileIndex + ".sync"].split(";"));
+				_.each(fileSyncIndexList, function(fileSyncIndex) {
 					localStorage[fileSyncIndex + ".contentCRC"] = "0";
 					// We store title CRC only for Google Drive synchronization
 					if(localStorage[fileSyncIndex + ".etag"] !== undefined) {
 						localStorage[fileSyncIndex + ".titleCRC"] = "0";
 					}
-				}
-			}
+				});
+			});
 			version = "v1";
 		}
+		
+		// from v1 to v2
+		if(version == "v1") {
+			
+			var SYNC_PROVIDER_GDRIVE = "sync." + PROVIDER_GDRIVE + ".";
+			var SYNC_PROVIDER_DROPBOX = "sync." + PROVIDER_DROPBOX + ".";
+			var fileIndexList = _.compact(localStorage["file.list"].split(";"));
+			_.each(fileIndexList, function(fileIndex) {
+				var fileSyncIndexList = _.compact(localStorage[fileIndex + ".sync"].split(";"));
+				_.each(fileSyncIndexList, function(fileSyncIndex) {
+					var syncAttributes = {};
+					if (fileSyncIndex.indexOf(SYNC_PROVIDER_GDRIVE) === 0) {
+						syncAttributes.provider = PROVIDER_GDRIVE;
+						syncAttributes.id = fileSyncIndex.substring(SYNC_PROVIDER_GDRIVE.length);
+						syncAttributes.etag = localStorage[fileSyncIndex + ".etag"];
+						syncAttributes.contentCRC = localStorage[fileSyncIndex + ".contentCRC"];
+						syncAttributes.titleCRC = localStorage[fileSyncIndex + ".titleCRC"];
+					}
+					else if (fileSyncIndex.indexOf(SYNC_PROVIDER_DROPBOX) === 0) {
+						syncAttributes.provider = PROVIDER_DROPBOX;
+						syncAttributes.path = decodeURIComponent(fileSyncIndex.substring(SYNC_PROVIDER_DROPBOX.length));
+						syncAttributes.version = localStorage[fileSyncIndex + ".version"];
+						syncAttributes.contentCRC = localStorage[fileSyncIndex + ".contentCRC"];
+					}
+					localStorage[fileSyncIndex] = JSON.stringify(syncAttributes);
+					localStorage.remoteItem(fileSyncIndex + ".etag");
+					localStorage.remoteItem(fileSyncIndex + ".version");
+					localStorage.remoteItem(fileSyncIndex + ".contentCRC");
+					localStorage.remoteItem(fileSyncIndex + ".titleCRC");
+				});
+			});
+			version = "v2";
+		}
 		localStorage["version"] = version;
 	}
 	
@ -586,13 +620,13 @@ define(
 			core.resetModalInputs();
 		});
 		
-		// Init asyncTaskRunner
-		asyncTaskRunner.init(core);
+		// Init asyncRunner
+		asyncRunner.init(core);
 		
 		// Init helpers
-		googleHelper.init(core, fileManager);
-		dropboxHelper.init(core, fileManager);
-		githubHelper.init(core, fileManager);
+		googleHelper.init(core);
+		dropboxHelper.init(core);
+		githubHelper.init(core);
 		
 		// Init synchronizer
 		synchronizer.init(core, fileManager);
@ -614,7 +648,7 @@ define(
 				return;
 			}
 			synchronizer.sync();
-			asyncTaskRunner.runTask();
+			asyncRunner.runTask();
 			checkOnline();
 		}, 1000);
 	};
--- a/js/dropbox-helper.js
+++ b/js/dropbox-helper.js
@ -1,8 +1,7 @@
-define(["jquery", "async-runner"], function($, asyncTaskRunner) {
+define(["jquery", "async-runner"], function($, asyncRunner) {

 	// Dependencies
 	var core = undefined;
-	var fileManager = undefined;

 	var client = undefined;
 	var authenticated = false;
@ -10,219 +9,194 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 	var dropboxHelper = {};

 	// Try to connect dropbox by downloading client.js
-	function connect(callback) {
-		callback = callback || core.doNothing;
-		if(core.isOffline === true) {
-			client = undefined;
-			core.showMessage("Operation not available in offline mode.");
-			callback(true);
-			return;
-		}		
-		if (client !== undefined) {
-			callback();
-			return;
-		}
-		$.ajax({
-			url : "lib/dropbox.min.js",
-			dataType : "script", timeout : AJAX_TIMEOUT
-		}).done(function() {
-			client = new Dropbox.Client({
-			    key: DROPBOX_APP_KEY,
-			    secret: DROPBOX_APP_SECRET
+	function connect(task) {
+		task.onRun(function() {
+			if(core.isOffline === true) {
+				client = undefined;
+				core.showMessage("Operation not available in offline mode.");
+				task.error();
+				return;
+			}		
+			if (client !== undefined) {
+				task.chain();
+				return;
+			}
+			$.ajax({
+				url : "lib/dropbox.min.js",
+				dataType : "script", timeout : AJAX_TIMEOUT
+			}).done(function() {
+				client = new Dropbox.Client({
+				    key: DROPBOX_APP_KEY,
+				    secret: DROPBOX_APP_SECRET
+				});
+				client.authDriver(new Dropbox.Drivers.Popup({
+				    receiverUrl: BASE_URL + "dropbox-oauth-receiver.html",
+				    rememberUser: true
+				}));
+				task.chain();
+			}).fail(function() {
+				core.setOffline();
+				task.error(new Error("Network timeout"));
 			});
-			client.authDriver(new Dropbox.Drivers.Popup({
-			    receiverUrl: BASE_URL + "dropbox-oauth-receiver.html",
-			    rememberUser: true
-			}));
-			callback();
-		}).fail(function() {
-			core.setOffline();
-			callback(true);
 		});
 	}

 	// Try to authenticate with Oauth
-	function authenticate(callback, immediate) {
-		callback = callback || core.doNothing;
-		if (immediate === undefined) {
-			immediate = true;
-		}
-		connect(function(error) {
-			if (error) {
-				callback(error);
-				return;
-			}
+	function authenticate(task) {
+		task.onRun(function() {
 			if (authenticated === true) {
-				callback();
+				task.chain();
 				return;
 			}
-			if (immediate === false) {
-				core.showMessage("Please make sure the Dropbox authorization popup is not blocked by your browser.");
-				asyncTaskRunner.setCurrentTaskTimeout(AUTH_POPUP_TIMEOUT);
+			var immediate = true;
+			function localAuthenticate() {
+				if (immediate === false) {
+					core.showMessage("Please make sure the Dropbox authorization popup is not blocked by your browser.");
+					// If not immediate we add time for user to enter his credentials
+					task.timeout = ASYNC_TASK_LONG_TIMEOUT;
+				}
+				client.reset();
+				client.authenticate({interactive: !immediate}, function(error, client) {
+					// Success
+					if (client.authState === Dropbox.Client.DONE) {
+						authenticated = true;
+						task.chain();
+						return;
+					}
+					// If immediate did not work retry without immediate flag
+					if (immediate === true) {
+						immediate = false;
+						task.chain(localAuthenticate);
+						return;
+					}
+					// Error
+					var errorMsg = "Access to Dropbox account is not authorized.";
+					core.showError(errorMsg);
+					task.error(new Error(errorMsg));
+				});
 			}
-			client.authenticate({interactive: !immediate}, function(error, client) {
-				if (client.authState === Dropbox.Client.DONE) {
-					callback();
-					return;
-				}
-
-				// If immediate did not work retry without immediate flag
-				if (client !== undefined && immediate === true) {
-					authenticate(callback, false);
-					return;
-				}
-				// Notify error
-				callback(true);
-			});
+			task.chain(localAuthenticate);
 		});
 	}

 	dropboxHelper.upload = function(path, content, callback) {
 		callback = callback || core.doNothing;
-		var syncIndex = undefined;
-		var asyncTask = {};
-		asyncTask.run = function() {
-			authenticate(function(error) {
-				if (error) {
-					handleError(error, asyncTask, callback);
+		var result = undefined;
+		var task = asyncRunner.createTask();
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {
+			client.writeFile(path, content, function(error, stat) {
+				if (!error) {
+					result = stat;
+					task.chain();
 					return;
 				}
-
-				client.writeFile(path, content, function(error, stat) {
-					if (!error) {
-						syncIndex = SYNC_PROVIDER_DROPBOX + encodeURIComponent(stat.path.toLowerCase());
-						localStorage[syncIndex + ".version"] = stat.versionTag;
-						asyncTask.success();
-						return;
-					}
-					// Handle error
-					if(error.status === Dropbox.ApiError.INVALID_PARAM) {
-						error = 'Could not upload document into path "' + path + '".';
-					}
-					handleError(error, asyncTask, callback);
-				});
+				// Handle error
+				if(error.status === Dropbox.ApiError.INVALID_PARAM) {
+					error = 'Could not upload document into path "' + path + '".';
+				}
+				handleError(error, task, callback);
 			});
-		};
-		asyncTask.onSuccess = function() {
-			callback(undefined, syncIndex);
-		};
-		asyncTask.onError = function() {
-			callback(true);
-		};
-		asyncTaskRunner.addTask(asyncTask);
+		});
+		task.onSuccess(function() {
+			callback(undefined, result);
+		});
+		task.onError(function(error) {
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};

 	dropboxHelper.checkUpdates = function(lastChangeId, callback) {
 		callback = callback || core.doNothing;
 		var changes = [];
 		var newChangeId = lastChangeId || 0;
-		var asyncTask = {};
-		asyncTask.run = function() {
-			function retrievePageOfChanges(changeId) {
-				if(asyncTask.finished === true) {
-					return;
-				}
-				authenticate(function(error) {
+		var task = asyncRunner.createTask();
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {
+			function retrievePageOfChanges() {
+				client.pullChanges(newChangeId, function(error, pullChanges) {
 					if (error) {
-						handleError(error, asyncTask, callback);
+						handleError(error, task, callback);
 						return;
 					}
-
-					client.pullChanges(changeId, function(error, pullChanges) {
-						if (error) {
-							handleError(error, asyncTask, callback);
-							return;
-						}
-						
-						// Retrieve success
-						newChangeId = pullChanges.cursor();
-						if(pullChanges.changes !== undefined) {
-							for(var i=0; i<pullChanges.changes.length; i++) {
-								var item = pullChanges.changes[i];
-								var version = localStorage[SYNC_PROVIDER_DROPBOX
-								    + encodeURIComponent(item.path.toLowerCase()) + ".version"];
-								if(version && (item.wasRemoved || item.stat.versionTag != version)) {
-									changes.push(item);
-								}
+					// Retrieve success
+					newChangeId = pullChanges.cursor();
+					if(pullChanges.changes !== undefined) {
+						for(var i=0; i<pullChanges.changes.length; i++) {
+							var item = pullChanges.changes[i];
+							var version = localStorage[SYNC_PROVIDER_DROPBOX
+							    + encodeURIComponent(item.path.toLowerCase()) + ".version"];
+							if(version && (item.wasRemoved || item.stat.versionTag != version)) {
+								changes.push(item);
 							}
 						}
-						if (pullChanges.shouldPullAgain) {
-							retrievePageOfChanges(newChangeId);
-						} else {
-							asyncTask.success();
-						}
-					});
+					}
+					if (pullChanges.shouldPullAgain) {
+						task.chain(retrievePageOfChanges);
+					} else {
+						task.chain();
+					}
 				});
 			}
-			retrievePageOfChanges(newChangeId);
-		};
-		asyncTask.onSuccess = function() {
+			task.chain(retrievePageOfChanges);
+		});
+		task.onSuccess(function() {
 			callback(undefined, changes, newChangeId);
-		};
-		asyncTask.onError = function() {
-			callback(true);
-		};
-		asyncTaskRunner.addTask(asyncTask);
+		});
+		task.onError(function(error) {
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};

 	dropboxHelper.downloadMetadata = function(paths, callback) {
 		callback = callback || core.doNothing;
-		result = result || [];
-	
-		var path = paths.pop();
-		var asyncTask = {};
-		asyncTask.run = function() {
+		var result = [];
+		var task = asyncRunner.createTask();
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {
 			function recursiveDownloadMetadata() {
-				if(asyncTask.finished === true) {
-					return;
-				}
 				if(paths.length === 0) {
-					asyncTask.success();
+					task.chain();
 					return;
 				}
-				authenticate(function(error) {
-					if (error) {
-						handleError(error, asyncTask, callback);
+				var path = paths.pop();
+				client.stat(path, function(error, stat) {
+					if(stat) {
+						result.push(stat);
+						task.chain(recursiveDownloadMetadata);
 						return;
 					}
-
-					client.stat(path, function(error, stat) {
-						if(stat) {
-							result.push(stat);
-							recursiveDownloadMetadata();
-							return;
-						}
-						handleError(error, asyncTask, callback);
-					});
+					handleError(error, task, callback);
 				});
 			}
-			recursiveDownloadMetadata();
-		};
-		asyncTask.onSuccess = function() {
+			task.chain(recursiveDownloadMetadata);
+		});
+		task.onSuccess(function() {
 			callback(undefined, result);
-		};
-		asyncTask.onError = function() {
-			callback(true);
-		};
-		asyncTaskRunner.addTask(asyncTask);
+		});
+		task.onError(function(error) {
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};

-	dropboxHelper.downloadContent = function(objects, callback, result) {
+	dropboxHelper.downloadContent = function(objects, callback) {
 		callback = callback || core.doNothing;
-		result = result || [];
-		
-		var asyncTask = {};
-		asyncTask.run = function() {
-			
+		var result = [];
+		var task = asyncRunner.createTask();
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {			
 			function recursiveDownloadContent() {
-				if(asyncTask.finished === true) {
-					return;
-				}
 				if(objects.length === 0) {
-					asyncTask.success();
+					task.chain();
 					return;
 				}
-				
 				var object = objects.pop();
 				result.push(object);
 				var file = undefined;
@ -235,44 +209,31 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 					file = object.stat;
 				}
 				if(!file) {
-					recursiveDownloadContent();
+					task.chain(recursiveDownloadContent);
 					return;
 				}
-				authenticate(function(error) {
-					if (error) {
-						handleError(error, asyncTask, callback);
+				client.readFile(file.path, function(error, data) {
+					if(data) {
+						file.content = data;
+						recursiveDownloadContent();
 						return;
 					}
-					
-					client.readFile(file.path, function(error, data) {
-						if(data) {
-							file.content = data;
-							recursiveDownloadContent();
-							return;
-						}
-						handleError(error, asyncTask, callback);
-					});
+					handleError(error, task, callback);
 				});
 			}
-			recursiveDownloadContent();
-		};
-		asyncTask.onSuccess = function() {
+			task.chain(recursiveDownloadContent);
+		});
+		task.onSuccess(function() {
 			callback(undefined, result);
-		};
-		asyncTask.onError = function() {
-			callback(true);
-		};
-		asyncTaskRunner.addTask(asyncTask);
+		});
+		task.onError(function(error) {
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};
 	
-	function handleError(error, asyncTask, callback) {
-		var errorMsg = undefined;
-		asyncTask.onError = function() {
-			if (errorMsg !== undefined) {
-				core.showError(errorMsg);
-			}
-			callback(errorMsg);
-		};
+	function handleError(error, task, callback) {
+		var errorMsg = true;
 		if (error) {
 			console.error(error);
 			// Try to analyze the error
@ -281,7 +242,20 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 			} else if (error.status === Dropbox.ApiError.INVALID_TOKEN
 				|| error.status === Dropbox.ApiError.OAUTH_ERROR) {
 				authenticated = false;
-				errorMsg = "Access to Dropbox is not authorized.";
+				task.retry();
+				return;
+			} else if(error.status === Dropbox.ApiError.INVALID_PARAM && error.responseText
+					.indexOf("oauth_nonce") !== -1) {
+				// A bug I guess...
+				_.each(_.keys(localStorage), function(key) {
+					// We have to remove the Oauth cache from the localStorage
+					if(key.indexOf("dropbox-auth") === 0) {
+						localStorage.removeItem(key);
+					}
+				});
+				authenticated = false;
+				task.retry();
+				return;
 			} else if (error.status === Dropbox.ApiError.NETWORK_ERROR) {
 				client = undefined;
 				authenticated = false;
@ -290,31 +264,27 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 				errorMsg = "Dropbox error ("
 					+ error.status + ").";
 			}
+			core.showError(errorMsg);
 		}
-		asyncTask.error();
+		task.error(new Error(errorMsg));
 	}

 	var pickerLoaded = false;
-	function loadPicker(callback) {
-		if (pickerLoaded === true) {
-			callback();
-			return;
-		}
-		connect(function(error) {
-			if (error) {
-				pickerLoaded = false;
-				callback(error);
+	function loadPicker(task) {
+		task.onRun(function() {
+			if (pickerLoaded === true) {
+				task.chain();
 				return;
 			}
-
 			$.ajax({
 				url : "https://www.dropbox.com/static/api/1/dropbox.js",
 				dataType : "script", timeout : AJAX_TIMEOUT
 			}).done(function() {
 				pickerLoaded = true;
-				callback();
+				task.chain();
 			}).fail(function() {
-				callback(true);
+				core.setOffline();
+				task.error();
 			});
 		});
 	}
@ -322,78 +292,40 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 	dropboxHelper.picker = function(callback) {
 		callback = callback || core.doNothing;
 		var paths = [];
-		
-		var asyncTask = {};
-		asyncTask.run = function() {
-			loadPicker(function(error) {
-				if (error) {
-					handleError(error, asyncTask, callback);
-					return;
+		var task = asyncRunner.createTask();
+		// Add some time for user to choose his files
+		task.timeout = ASYNC_TASK_LONG_TIMEOUT;
+		connect(task);
+		loadPicker(task);
+		task.onRun(function() {			
+			var options = {};
+			options.multiselect = true;
+			options.linkType = "direct";
+			options.success = function(files) {
+				for(var i=0; i<files.length; i++) {
+					var path = files[i].link;
+					path = path.replace(/.*\/view\/[^\/]*/, "");
+					paths.push(decodeURI(path));
 				}
-				var options = {};
-				options.multiselect = true;
-				options.linkType = "direct";
-				options.success = function(files) {
-					for(var i=0; i<files.length; i++) {
-						var path = files[i].link;
-						path = path.replace(/.*\/view\/[^\/]*/, "");
-						paths.push(decodeURI(path));
-					}
-					asyncTask.success();
-	            };
-	            options.cancel = function() {
-					asyncTask.error();
-	            };
-				Dropbox.choose(options);
-				core.showMessage("Please make sure the Dropbox chooser popup is not blocked by your browser.");
-			});
-		};
-		asyncTask.onSuccess = function() {
-			callback(undefined, paths);
-		};
-		asyncTask.onError = function() {
-			callback(true);
-		};
-		asyncTaskRunner.addTask(asyncTask);
-	};
-
-	dropboxHelper.importFiles = function(paths) {
-		dropboxHelper.downloadMetadata(paths, function(error, result) {
-			if(error) {
-				return;
-			}
-			dropboxHelper.downloadContent(result, function(error, result) {
-				if(error) {
-					return;
-				}
-				for(var i=0; i<result.length; i++) {
-					var file = result[i];
-					syncIndex = SYNC_PROVIDER_DROPBOX + encodeURIComponent(file.path.toLowerCase());
-					localStorage[syncIndex + ".version"] = file.versionTag;
-					var contentCRC = core.crc32(file.content);
-					localStorage[syncIndex + ".contentCRC"] = contentCRC;
-					var fileIndex = fileManager.createFile(file.name, file.content, [syncIndex]);
-					fileManager.selectFile(fileIndex);
-					core.showMessage('"' + file.name + '" imported successfully from Dropbox.');
-				}
-			});
+				task.chain();
+            };
+            options.cancel = function() {
+				task.chain();
+            };
+			Dropbox.choose(options);
+			core.showMessage("Please make sure the Dropbox chooser popup is not blocked by your browser.");
 		});
+		task.onSuccess(function() {
+			callback(undefined, paths);
+		});
+		task.onError(function(error) {
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};

-	dropboxHelper.init = function(coreModule, fileManagerModule) {
+	dropboxHelper.init = function(coreModule) {
 		core = coreModule;
-		fileManager = fileManagerModule;
-	};
-	
-	dropboxHelper.checkPath = function(path) {
-		if(!path.match(/^[^\\<>:"\|?\*]+$/)) {
-			core.showError('"' + path + '" contains invalid characters.');
-			return undefined;
-		}
-		if(path.indexOf("/") !== 0) {
-			return "/" + path;
-		}
-		return path;
 	};
 	
 	return dropboxHelper;
--- a/js/dropbox-provider.js
+++ b/js/dropbox-provider.js
@ -2,16 +2,116 @@ define(["jquery", "dropbox-helper"], function($, dropboxHelper) {
 	
 	// Dependencies
 	var core = undefined;
+	var fileManager = undefined;
 	
 	var dropboxProvider = {
-		providerType: PROVIDER_TYPE_PUBLISH_FLAG,
+		providerType: PROVIDER_TYPE_SYNC_FLAG | PROVIDER_TYPE_PUBLISH_FLAG,
 		providerId: PROVIDER_DROPBOX,
 		providerName: "Dropbox",
 		defaultPublishFormat: "template"
 	};
 	
+	function checkPath(path) {
+		if(path === undefined) {
+			return undefined;
+		}
+		if(!path.match(/^[^\\<>:"\|?\*]+$/)) {
+			core.showError('"' + path + '" contains invalid characters.');
+			return undefined;
+		}
+		if(path.indexOf("/") !== 0) {
+			return "/" + path;
+		}
+		return path;
+	}
+	
+	function createSyncAttributes(path, versionTag, content) {
+		var syncAttributes = {};
+		syncAttributes.provider = PROVIDER_DROPBOX;
+		syncAttributes.path = path;
+		syncAttributes.version = versionTag;
+		syncAttributes.contentCRC = core.crc32(content);
+		var syncIndex = "sync." + PROVIDER_DROPBOX + "." + encodeURIComponent(file.path.toLowerCase());
+		localStorage[syncIndex] = JSON.stringify(syncAttributes);
+		return syncIndex;
+	}
+	
+	function importFilesFromPaths(paths) {
+		dropboxHelper.downloadMetadata(paths, function(error, result) {
+			if(error) {
+				return;
+			}
+			dropboxHelper.downloadContent(result, function(error, result) {
+				if(error) {
+					return;
+				}
+				_.each(result, function(file) {
+					var syncIndex = createSyncAttributes(file.path, file.versionTag, file.content);
+					var fileIndex = fileManager.createFile(file.name, file.content, [syncIndex]);
+					fileManager.selectFile(fileIndex);
+					core.showMessage('"' + file.name + '" imported successfully from Dropbox.');
+				});
+			});
+		});
+	}
+
+	dropboxProvider.importFiles = function() {
+		dropboxHelper.picker(function(error, paths) {
+			if(error) {
+				return;
+			}
+			var importPaths = [];
+			_.each(paths, function(path) {
+				var syncIndex = "sync." + PROVIDER_DROPBOX + "." + encodeURIComponent(path.toLowerCase());
+				var fileIndex = fileManager.getFileIndexFromSync(syncIndex);
+				if(fileIndex !== undefined) {
+					var title = localStorage[fileIndex + ".title"];
+					core.showError('"' + title + '" was already imported');
+					return;
+				}
+				importPaths.push(path);
+			});
+			dropboxHelper.importFiles(importPaths);			
+		});
+	};
+	
+	function exportFileToPath(path, title, content, callback) {
+		path = dropboxHelper.checkPath(path);
+		if(path === undefined) {
+			callback(true);
+			return;
+		}
+		// Check that file is not synchronized with an other one
+		var syncIndex = "sync." + PROVIDER_DROPBOX + "." + encodeURIComponent(path.toLowerCase());
+		var fileIndex = fileManager.getFileIndexFromSync(syncIndex);
+		if(fileIndex !== undefined) {
+			var existingTitle = localStorage[fileIndex + ".title"];
+			core.showError('File path is already synchronized with "' + existingTitle + '"');
+			callback(true);
+			return;
+		}
+		dropboxHelper.upload(path, content, function(error, result) {
+			if (error) {
+				callback(error);
+				return;
+			}
+			syncIndex = createSyncAttributes(result.path, result.versionTag, content);
+			callback(undefined, syncIndex);
+		});
+	}
+	
+	dropboxProvider.exportFile = function(event, title, content, callback) {
+		var path = core.getInputValue($("#input-sync-export-dropbox-path"), event);
+		exportFileToPath(path);
+	};
+
+	dropboxProvider.exportManual = function(event, title, content, callback) {
+		var path = core.getInputValue($("#input-sync-manual-dropbox-path"), event);
+		exportFileToPath(path);
+	};
+	
 	dropboxProvider.publish = function(publishAttributes, title, content, callback) {
-		var path = dropboxHelper.checkPath(publishAttributes.path);
+		var path = checkPath(publishAttributes.path);
 		if(path === undefined) {
 			callback(true);
 			return;
@ -28,8 +128,9 @@ define(["jquery", "dropbox-helper"], function($, dropboxHelper) {
 		return publishAttributes;
 	};

-	dropboxProvider.init = function(coreModule) {
+	dropboxProvider.init = function(coreModule, fileManagerModule) {
 		core = coreModule;
+		fileManager = fileManagerModule;
 	};

 	return dropboxProvider;
--- a/js/file-manager.js
+++ b/js/file-manager.js
@ -40,7 +40,7 @@ define(["jquery", "google-helper", "dropbox-helper", "github-helper", "synchroni

 		// Update the file titles
 		fileManager.updateFileTitles();
-		refreshManageSync();
+		synchronizer.refreshManageSync();
 		publisher.notifyPublish();
 		
 		// Recreate the editor
@ -186,14 +186,11 @@ define(["jquery", "google-helper", "dropbox-helper", "github-helper", "synchroni
 			localStorage[fileIndex + ".sync"] = localStorage[fileIndex + ".sync"].replace(";"
 				+ syncIndex + ";", ";");
 			if(fileManager.isCurrentFileIndex(fileIndex)) {
-				refreshManageSync();
+				synchronizer.refreshManageSync();
 			}
 		}
-		// Remove ETAG, version, CRCs (if any) 
-		localStorage.removeItem(syncIndex + ".etag");
-		localStorage.removeItem(syncIndex + ".version");
-		localStorage.removeItem(syncIndex + ".contentCRC");
-		localStorage.removeItem(syncIndex + ".titleCRC");
+		// Remove sync attributes
+		localStorage.removeItem(syncIndex);
 	};
 	
 	// Get the fileIndex associated to a syncIndex
@ -215,7 +212,7 @@ define(["jquery", "google-helper", "dropbox-helper", "github-helper", "synchroni
 				publisher.notifyPublish();
 			}
 		}
-		// Remove publish object
+		// Remove publish attributes
 		localStorage.removeItem(publishIndex);
 	};
 	
@ -228,148 +225,6 @@ define(["jquery", "google-helper", "dropbox-helper", "github-helper", "synchroni
 			}).value();
 	};
 	
-	function uploadGdrive(fileId, folderId) {
-		var fileIndex = fileManager.getCurrentFileIndex();
-		var content = localStorage[fileIndex + ".content"];
-		var title = localStorage[fileIndex + ".title"];
-		googleHelper.upload(fileId, folderId, title, content, function(syncIndex) {
-			if (syncIndex === undefined) {
-				return;
-			}
-			var contentCRC = core.crc32(content);
-			localStorage[syncIndex + ".contentCRC"] = contentCRC;
-			var titleCRC = core.crc32(title);
-			localStorage[syncIndex + ".titleCRC"] = titleCRC;
-			localStorage[fileIndex + ".sync"] += syncIndex + ";";
-			refreshManageSync();
-			fileManager.updateFileTitles();
-			core.showMessage('"' + title
-				+ '" will now be synchronized on Google Drive.');
-		});
-	}
-	
-	function manualGdrive(fileId) {
-		if(!fileId) {
-			return;
-		}
-		// Check that file is not synchronized with an other one
-		var syncIndex = SYNC_PROVIDER_GDRIVE + fileId;
-		var fileIndex = fileManager.getFileIndexFromSync(syncIndex);
-		if(fileIndex !== undefined) {
-			var title = localStorage[fileIndex + ".title"];
-			core.showError('File ID is already synchronized with "' + title + '"');
-			return;
-		}
-		uploadGdrive(fileId);
-	}
-	
-	function importGdrive(ids) {
-		if(ids === undefined) {
-			return;
-		}
-		var importIds = [];
-		for(var i=0; i<ids.length; i++) {
-			var fileId = ids[i];
-			var syncIndex = SYNC_PROVIDER_GDRIVE + fileId;
-			var fileIndex = fileManager.getFileIndexFromSync(syncIndex);
-			if(fileIndex !== undefined) {
-				var title = localStorage[fileIndex + ".title"];
-				core.showError('"' + title + '" was already imported');
-				continue;
-			}
-			importIds.push(fileId);
-		}
-		googleHelper.importFiles(importIds);
-	}
-	
-	function manualDropbox(path) {
-		if(!path) {
-			return;
-		}
-		path = dropboxHelper.checkPath(path);
-		if(path === undefined) {
-			return;
-		}
-		// Check that file is not synchronized with an other one
-		var syncIndex = SYNC_PROVIDER_DROPBOX + encodeURIComponent(path.toLowerCase());
-		var fileIndex = fileManager.getFileIndexFromSync(syncIndex);
-		if(fileIndex !== undefined) {
-			var title = localStorage[fileIndex + ".title"];
-			core.showError('Path "' + path + '" is already synchronized with "' + title + '"');
-			return;
-		}
-		var fileIndex = fileManager.getCurrentFileIndex();
-		var content = localStorage[fileIndex + ".content"];
-		var title = localStorage[fileIndex + ".title"];
-		dropboxHelper.upload(path, content, function(error, syncIndex) {
-			if (error) {
-				return;
-			}
-			var contentCRC = core.crc32(content);
-			localStorage[syncIndex + ".contentCRC"] = contentCRC;
-			localStorage[fileIndex + ".sync"] += syncIndex + ";";
-			refreshManageSync();
-			fileManager.updateFileTitles();
-			core.showMessage('"' + title
-				+ '" will now be synchronized on Dropbox.');
-		});
-	}
-	
-	function importDropbox(error, paths) {
-		if(error) {
-			return;
-		}
-		var importPaths = [];
-		for(var i=0; i<paths.length; i++) {
-			var filePath = paths[i];
-			var syncIndex = SYNC_PROVIDER_DROPBOX + encodeURIComponent(filePath.toLowerCase());
-			var fileIndex = fileManager.getFileIndexFromSync(syncIndex);
-			if(fileIndex !== undefined) {
-				var title = localStorage[fileIndex + ".title"];
-				core.showError('"' + title + '" was already imported');
-				continue;
-			}
-			importPaths.push(filePath);
-		}
-		dropboxHelper.importFiles(importPaths);
-	}
-	
-	function refreshManageSync() {
-		var fileIndex = fileManager.getCurrentFileIndex();
-		var syncIndexList = _.compact(localStorage[fileIndex + ".sync"].split(";"));
-		$(".msg-no-sync, .msg-sync-list").addClass("hide");
-		$("#manage-sync-list .input-append").remove();
-		if (syncIndexList.length > 0) {
-			$(".msg-sync-list").removeClass("hide");
-		} else {
-			$(".msg-no-sync").removeClass("hide");
-		}
-		_.each(syncIndexList, function(syncIndex) {
-			var line = $("<div>").addClass("input-prepend input-append");
-			if (syncIndex.indexOf(SYNC_PROVIDER_GDRIVE) === 0) {
-				line.append($("<span>").addClass("add-on").prop("title", "Google Drive").html(
-					'<i class="icon-gdrive"></i>'));
-				line.append($("<input>").prop("type", "text").prop(
-					"disabled", true).addClass("span5").val(
-					syncIndex.substring(SYNC_PROVIDER_GDRIVE.length)));
-			}
-			else if (syncIndex.indexOf(SYNC_PROVIDER_DROPBOX) === 0) {
-				line.append($("<span>").addClass("add-on").prop("title", "Dropbox").html(
-				'<i class="icon-dropbox"></i>'));
-				line.append($("<input>").prop("type", "text").prop(
-					"disabled", true).addClass("span5").val(
-						decodeURIComponent(syncIndex.substring(SYNC_PROVIDER_DROPBOX.length))));
-			}
-			line.append($("<a>").addClass("btn").html(
-				'<i class="icon-trash"></i>').prop("title",
-				"Remove this location").click(function() {
-				fileManager.removeSync(syncIndex);
-				fileManager.updateFileTitles();
-			}));
-			$("#manage-sync-list").append(line);
-		});
-	}
-	
 	fileManager.init = function(coreModule) {
 		core = coreModule;
 		
@ -388,18 +243,29 @@ define(["jquery", "google-helper", "dropbox-helper", "github-helper", "synchroni
 			$(this).hide();
 			$("#file-title-input").show().focus();
 		});
-		$("#file-title-input").blur(function() {
-			var title = $.trim($(this).val());
+		function applyTitle(input) {
+			var title = $.trim(input.val());
+			var fileIndexTitle = fileManager.getCurrentFileIndex() + ".title";
 			if (title) {
-				var fileIndexTitle = fileManager.getCurrentFileIndex() + ".title";
 				if (title != localStorage[fileIndexTitle]) {
 					localStorage[fileIndexTitle] = title;
 					fileManager.updateFileTitles();
 					fileManager.saveFile();
 				}
 			}
-			$(this).hide();
+			input.hide().val(localStorage[fileIndexTitle]);
 			$("#file-title").show();
+		}
+		$("#file-title-input").blur(function() {
+			applyTitle($(this));
+		}).keyup(function(e) {
+			if (e.keyCode == 13) {
+				applyTitle($(this));
+			}
+			if (e.keyCode == 27) {
+				$(this).val("");
+				applyTitle($(this));
+			}
 		});
 		$(".action-download-md").click(
 			function() {
@ -422,38 +288,6 @@ define(["jquery", "google-helper", "dropbox-helper", "github-helper", "synchroni
 					+ core.encodeBase64(content);
 				window.open(uriContent, 'file');
 			});
-		
-		// Synchronize actions
-		$(".action-upload-gdrive-root").click(function() {
-			uploadGdrive();
-		});
-		$(".action-upload-gdrive-select").click(function() {
-			// This action is not available because picker does not support
-			// folder selection
-			googleHelper.picker(function(ids) {
-				if(ids !== undefined && ids.length !== 0) {
-					uploadGdrive(undefined, ids[0]);
-				}
-			}, true);
-		});
-		$(".action-download-gdrive").click(function() {
-			googleHelper.picker(importGdrive);
-		});
-		$(".action-manual-gdrive").click(function(event) {
-			var fileId = core.getInputValue($("#manual-gdrive-fileid"), event);
-			manualGdrive(fileId);
-		});
-		$(".action-download-dropbox").click(function() {
-			dropboxHelper.picker(importDropbox);
-		});
-		$(".action-upload-dropbox").click(function(event) {
-			var path = core.getInputValue($("#upload-dropbox-path"), event);
-			manualDropbox(path);
-		});
-		$(".action-manual-dropbox").click(function(event) {
-			var path = core.getInputValue($("#manual-dropbox-path"), event);
-			manualDropbox(path);
-		});
 	};

 	return fileManager;
--- a/js/gdrive-provider.js
+++ b/js/gdrive-provider.js
@ -0,0 +1,152 @@
+define(["jquery", "google-helper", "underscore"], function($, googleHelper) {
+	
+	// Dependencies
+	var core = undefined;
+	var fileManager = undefined;
+	
+	var gdriveProvider = {
+		providerType: PROVIDER_TYPE_SYNC_FLAG | PROVIDER_TYPE_PUBLISH_FLAG,
+		providerId: PROVIDER_GDRIVE,
+		providerName: "Gdrive",
+		defaultPublishFormat: "template"
+	};
+	
+	function createSyncAttributes(id, etag, content, title) {
+		var syncAttributes = {};
+		syncAttributes.provider = PROVIDER_GDRIVE;
+		syncAttributes.id = id;
+		syncAttributes.etag = etag;
+		syncAttributes.contentCRC = core.crc32(content);
+		syncAttributes.titleCRC = core.crc32(title);
+		var syncIndex = "sync." + PROVIDER_GDRIVE + "." + file.id;
+		localStorage[syncIndex] = JSON.stringify(syncAttributes);
+		return syncIndex;
+	}
+	
+	function importFilesFromIds(ids) {
+		googleHelper.downloadMetadata(ids, function(error, result) {
+			if(error) {
+				return;
+			}
+			googleHelper.downloadContent(result, function(error, result) {
+				if(error) {
+					return;
+				}
+				_.each(result, function(file) {
+					var syncIndex = createSyncAttributes(file.id, file.etag, file.content, file.title);
+					var fileIndex = fileManager.createFile(file.title, file.content, [syncIndex]);
+					fileManager.selectFile(fileIndex);
+					core.showMessage('"' + file.title + '" imported successfully from Google Drive.');
+				});
+			});
+		});
+	};
+
+	gdriveProvider.importFiles = function() {
+		googleHelper.picker(function(error, ids) {
+			if(ids === undefined) {
+				return;
+			}
+			var importIds = [];
+			_.each(ids, function(id) {
+				var syncIndex = "sync." + PROVIDER_GDRIVE + "." + id;
+				var fileIndex = fileManager.getFileIndexFromSync(syncIndex);
+				if(fileIndex !== undefined) {
+					var title = localStorage[fileIndex + ".title"];
+					core.showError('"' + title + '" was already imported');
+					return;
+				}
+				importIds.push(id);
+			});
+			importFilesFromIds(importIds);
+		});
+	};
+	
+	gdriveProvider.exportFile = function(event, title, content, callback) {
+		googleHelper.upload(undefined, undefined, title, content, function(error, result) {
+			if (error) {
+				callback(error);
+				return;
+			}
+			var syncIndex = createSyncAttributes(result.id, result.etag, content, title);
+			callback(undefined, syncIndex);
+		});
+	};
+
+	gdriveProvider.exportManual = function(event, title, content, callback) {
+		var id = core.getInputValue($("#input-sync-manual-gdrive-id"), event);
+		if(!id) {
+			return;
+		}
+		// Check that file is not synchronized with an other one
+		var syncIndex = "sync." + PROVIDER_GDRIVE + "." + id;
+		var fileIndex = fileManager.getFileIndexFromSync(syncIndex);
+		if(fileIndex !== undefined) {
+			var existingTitle = localStorage[fileIndex + ".title"];
+			core.showError('File ID is already synchronized with "' + existingTitle + '"');
+			callback(true);
+			return;
+		}
+		googleHelper.upload(id, undefined, title, content, function(error, result) {
+			if (error) {
+				callback(error);
+				return;
+			}
+			var syncIndex = createSyncAttributes(result.id, result.etag, content, title);
+			callback(undefined, syncIndex);
+		});
+	};
+	
+	gdriveProvider.publish = function(publishAttributes, title, content, callback) {
+		googleHelper.upload(publishAttributes.fileId, undefined, title, content, callback);
+	};
+
+	gdriveProvider.newPublishAttributes = function(event) {
+		var publishAttributes = {};
+		publishAttributes.fileId = $("#input-publish-gdrive-fileid").val() || undefined;
+		if(event.isPropagationStopped()) {
+			return undefined;
+		}
+		return publishAttributes;
+	};
+	
+	gdriveProvider.init = function(coreModule, fileManagerModule) {
+		core = coreModule;
+		fileManager = fileManagerModule;
+		
+		var state = localStorage["sync.gdrive.state"];
+		if(state === undefined) {
+			return;
+		}
+		localStorage.removeItem("sync.gdrive.state");
+		state = JSON.parse(state);
+		if (state.action == "create") {
+			googleHelper.upload(undefined, state.folderId, GDRIVE_DEFAULT_FILE_TITLE,
+				"", function(error, file) {
+				if(error) {
+					return;
+				}
+				var syncIndex = createSyncAttributes(file.id, file.etag, file.content, file.title);
+				var fileIndex = fileManager.createFile(file.title, file.content, [syncIndex]);
+				fileManager.selectFile(fileIndex);
+				core.showMessage('"' + file.title + '" created successfully on Google Drive.');
+			});
+		}
+		else if (state.action == "open") {
+			var importIds = [];
+			_.each(state.ids, function(id) {
+				var syncIndex = "sync." + PROVIDER_GDRIVE + "." + id;
+				var fileIndex = fileManager.getFileIndexFromSync(syncIndex);
+				if(fileIndex !== undefined) {
+					fileManager.selectFile(fileIndex);
+				}
+				else {
+					importIds.push(id);
+				}
+			});
+			importFilesFromIds(importIds);
+		}
+	};
+
+	return gdriveProvider;
+});
--- a/js/github-helper.js
+++ b/js/github-helper.js
@ -1,4 +1,4 @@
-define(["jquery", "async-runner"], function($, asyncTaskRunner) {
+define(["jquery", "async-runner"], function($, asyncRunner) {

 	// Dependencies
 	var core = undefined;
@ -9,18 +9,17 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 	var githubHelper = {};

 	// Try to connect github by downloading js file
-	function connect(callback) {
+	function connect(task) {
 		callback = callback || core.doNothing;
-		var asyncTask = {};
-		asyncTask.run = function() {
+		task.onRun(function() {
 			if(core.isOffline === true) {
 				connected = false;
 				core.showMessage("Operation not available in offline mode.");
-				asyncTask.error();
+				task.error();
 				return;
 			}
 			if (connected === true) {
-				asyncTask.success();
+				task.chain();
 				return;
 			}
 			$.ajax({
@ -28,159 +27,138 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 				dataType : "script", timeout : AJAX_TIMEOUT
 			}).done(function() {
 				connected = true;
-				asyncTask.success();
+				task.chain();
 			}).fail(function() {
-				asyncTask.error();
+				core.setOffline();
+				task.error(new Error("Network timeout"));
 			});
-		};
-		asyncTask.onSuccess = function() {
-			callback();
-		};
-		asyncTask.onError = function() {
-			core.setOffline();
-			callback();
-		};
-		asyncTaskRunner.addTask(asyncTask);
+		});
 	}

 	// Try to authenticate with Oauth
-	function authenticate(callback, immediate) {
-		callback = callback || core.doNothing;
-		connect(function() {
-			if (connected === false) {
-				callback();
+	function authenticate(task) {
+		var authWindow = undefined;
+		var intervalId = undefined;
+		task.onRun(function() {
+			if (github !== undefined) {
+				task.chain();
 				return;
 			}
-
-			var intervalId = undefined;
-			var authWindow = undefined;
 			var token = localStorage["githubToken"];
-			var errorMsg = "Access to GitHub is not authorized.";
-			var asyncTask = {};
-			asyncTask.run = function() {
-				if (github !== undefined) {
-					asyncTask.success();
-					return;
-				}
-				
-				if (token !== undefined) {
-					 github = new Github({
-						  token: token,
-						  auth: "oauth"
-						});
-					 asyncTask.success();
-					 return;
-				}
-				if(immediate === true) {
-					core.showError();
-					asyncTask.error();
-					return;
-				}
-				// We add time for user to enter his credentials
-				asyncTask.timeout = AUTH_POPUP_TIMEOUT;
-				core.showMessage("Please make sure the Github authorization popup is not blocked by your browser.");
+			if(token !== undefined) {
+				github = new Github({
+					  token: token,
+					  auth: "oauth"
+					});
+				task.chain();
+				return;
+			}
+			core.showMessage("Please make sure the Github authorization popup is not blocked by your browser.");
+			// We add time for user to enter his credentials
+			task.timeout = ASYNC_TASK_LONG_TIMEOUT;
+			var code = undefined;
+			function getCode() {
 				localStorage.removeItem("githubCode");
 				authWindow = core.popupWindow(
 					'github-oauth-client.html?client_id=' + GITHUB_CLIENT_ID,
 					'stackedit-github-oauth', 960, 600);
 				authWindow.focus();
 				intervalId = setInterval(function() {
-					var code = localStorage["githubCode"];
-					if(authWindow.closed === true || code !== undefined) {
-						localStorage.removeItem("githubCode");
+					if(authWindow.closed === true) {
+						clearInterval(intervalId);
+						authWindow = undefined;
+						intervalId = undefined;
+						code = localStorage["githubCode"];
 						if(code === undefined) {
-							asyncTask.error();
+							task.error();
 							return;
 						}
-						$.getJSON(GATEKEEPER_URL + "authenticate/" + code, function(data) {
-							if(data.token !== undefined) {
-								localStorage["githubToken"] = data.token;
-								asyncTask.success();
-							}
-							else {
-								asyncTask.error();
-							}
-						});
+						localStorage.removeItem("githubCode");
+						task.chain(getToken);
 					}
-				}, 500);
-			};
-			asyncTask.onSuccess = function() {
-				if(intervalId !== undefined) {
-					clearInterval(intervalId);
-				}
-				if (github !== undefined) {
-					callback();
-					return;
-				}
-				authenticate(callback, true);
-			};
-			asyncTask.onError = function() {
-				if(intervalId !== undefined) {
-					clearInterval(intervalId);
-				}
-				if(authWindow !== undefined) {
-					authWindow.close();
-				}
-				core.showError(errorMsg);
-				callback();
-			};
-			asyncTaskRunner.addTask(asyncTask);
+				});
+			}
+			function getToken() {
+				$.getJSON(GATEKEEPER_URL + "authenticate/" + code, function(data) {
+					if(data.token !== undefined) {
+						token = data.token;
+						localStorage["githubToken"] = token;
+						github = new Github({
+							  token: token,
+							  auth: "oauth"
+							});
+						task.chain();
+					}
+					else {
+						task.error();
+					}
+				});
+			}
+			task.chain(getCode);
+		});
+		task.onError(function() {
+			if(intervalId !== undefined) {
+				clearInterval(intervalId);
+			}
+			if(authWindow !== undefined) {
+				authWindow.close();
+			}
 		});
 	}

 	githubHelper.upload = function(reponame, branch, path, content, commitMsg, callback) {
 		callback = callback || core.doNothing;
-		authenticate(function() {
-			if (github === undefined) {
-				callback("error");
-				return;
-			}
-
-			var error = undefined;
-			var asyncTask = {};
-			asyncTask.run = function() {
+		var task = asyncRunner.createTask();
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {
+			var userLogin = undefined;
+			function getUserLogin() {
 				var user = github.getUser();
 				user.show(undefined, function(err, result) {
 					if(err) {
-						error = err.error;
-						asyncTask.error();
+						task.error(err);
 						return;
 					}
-					var repo = github.getRepo(result.login, reponame);
-					repo.write(branch, path, content, commitMsg, function(err) {
-						if(err) {
-							error = err.error;
-							asyncTask.error();
-							return;
-						}
-						asyncTask.success();
-					});
+					userLogin = result.login;
+					task.chain(write);
 				});
-			};
-			asyncTask.onSuccess = function() {
-				callback(error);
-			};
-			asyncTask.onError = function() {
-				if(error !== undefined) {
-					console.error(error);
-				}
-				var errorMsg = "Could not publish on GitHub.";
-				if(error === 401 || error === 403) {
+			}
+			function write() {
+				var repo = github.getRepo(userLogin, reponame);
+				repo.write(branch, path, content, commitMsg, function(err) {
+					if(err) {
+						task.error(err);
+						return;
+					}
+					task.chain();
+				});
+			}
+			task.chain(getUserLogin);
+		});
+		task.onSuccess(function() {
+			callback();
+		});
+		task.onError(function(err) {
+			var errorMsg = "Could not publish on GitHub.";
+			if(err !== undefined) {
+				console.error(err);
+				if(err.error === 401 || err.error === 403) {
 					github = undefined;
 					// Token must be renewed
 					localStorage.removeItem("githubToken");
 					errorMsg = "Access to GitHub is not authorized.";
 				}
-				else if(error === 0) {
+				else if(err.error === 0) {
 					connected = false;
 					github = undefined;
 					core.setOffline();
 				}
-				core.showError(errorMsg);
-				callback(error);
-			};
-			asyncTaskRunner.addTask(asyncTask);
+			}
+			core.showError(errorMsg);
+			callback(errorMsg);
 		});
+		asyncRunner.addTask(task);
 	};
 	
 	githubHelper.init = function(coreModule) {
--- a/js/google-helper.js
+++ b/js/google-helper.js
@ -1,8 +1,7 @@
-define(["jquery", "async-runner"], function($, asyncTaskRunner) {
+define(["jquery", "async-runner"], function($, asyncRunner) {

 	// Dependencies
 	var core = undefined;
-	var fileManager = undefined;

 	var connected = false;
 	var authenticated = false;
@ -10,254 +9,224 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 	var googleHelper = {};

 	// Try to connect Gdrive by downloading client.js
-	function connect(callback) {
-		callback = callback || core.doNothing;
-		var asyncTask = {};
-		asyncTask.run = function() {
+	function connect(task) {
+		task.onRun(function() {
 			if(core.isOffline === true) {
 				connected = false;
 				core.showMessage("Operation not available in offline mode.");
-				asyncTask.error();
+				task.error();
 				return;
 			}
 			if (connected === true) {
-				asyncTask.success();
+				task.chain();
 				return;
 			}
 			delayedFunction = function() {
-				asyncTask.success();
+				connected = true;
+				task.chain();
 			};
 			$.ajax({
 				url : "https://apis.google.com/js/client.js?onload=runDelayedFunction",
 				dataType : "script", timeout : AJAX_TIMEOUT
 			}).fail(function() {
-				asyncTask.error();
+				core.setOffline();
+				task.error(new Error("Network timeout"));
 			});
-		};
-		asyncTask.onSuccess = function() {
-			connected = true;
-			callback();
-		};
-		asyncTask.onError = function() {
-			core.setOffline();
-			callback();
-		};
-		asyncTaskRunner.addTask(asyncTask);
+		});
 	}

 	// Try to authenticate with Oauth
-	function authenticate(callback, immediate) {
-		callback = callback || core.doNothing;
-		if (immediate === undefined) {
-			immediate = true;
-		}
-		connect(function() {
-			if (connected === false) {
-				callback();
+	function authenticate(task) {
+		task.onRun(function() {
+			if (authenticated === true) {
+				task.chain();
 				return;
 			}
-
-			var asyncTask = {};
-			// If not immediate we add time for user to enter his credentials
-			if (immediate === false) {
-				asyncTask.timeout = AUTH_POPUP_TIMEOUT;
-			}
-			asyncTask.run = function() {
-				if (authenticated === true) {
-					asyncTask.success();
-					return;
-				}
+			var immediate = true;
+			function localAuthenticate() {
 				if (immediate === false) {
 					core.showMessage("Please make sure the Google authorization popup is not blocked by your browser.");
+					// If not immediate we add time for user to enter his credentials
+					task.timeout = ASYNC_TASK_LONG_TIMEOUT;
 				}
 				gapi.auth.authorize({ 'client_id' : GOOGLE_CLIENT_ID,
 					'scope' : GOOGLE_SCOPES, 'immediate' : immediate }, function(
 					authResult) {
 					gapi.client.load('drive', 'v2', function() {
 						if (!authResult || authResult.error) {
-							asyncTask.error();
+							// If immediate did not work retry without immediate flag
+							if (connected === true && immediate === true) {
+								immediate = false;
+								task.chain(localAuthenticate);
+								return;
+							}
+							// Error
+							var errorMsg = "Access to Google account is not authorized.";
+							core.showError(errorMsg);
+							task.error(new Error(errorMsg));
 							return;
 						}
+						// Success
 						authenticated = true;
-						asyncTask.success();
+						task.chain();
 					});
 				});
-			};
-			asyncTask.onSuccess = function() {
-				callback();
-			};
-			asyncTask.onError = function() {
-				// If immediate did not work retry without immediate flag
-				if (connected === true && immediate === true) {
-					authenticate(callback, false);
-					return;
-				}
-				callback();
-			};
-			asyncTaskRunner.addTask(asyncTask);
+			}
+			task.chain(localAuthenticate);
 		});
 	}

 	googleHelper.upload = function(fileId, parentId, title, content, callback) {
 		callback = callback || core.doNothing;
-		authenticate(function() {
-			if (connected === false) {
-				callback();
-				return;
+		var result = undefined;
+		var task = asyncRunner.createTask();
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {
+			var boundary = '-------314159265358979323846';
+			var delimiter = "\r\n--" + boundary + "\r\n";
+			var close_delim = "\r\n--" + boundary + "--";
+			var contentType = 'text/x-markdown';
+			var metadata = { title : title, mimeType : contentType };
+			if (parentId !== undefined) {
+				// Specify the directory
+				metadata.parents = [ { kind : 'drive#fileLink',
+					id : parentId } ];
+			}
+			var path = '/upload/drive/v2/files';
+			var method = 'POST';
+			var etag = undefined;
+			if (fileId !== undefined) {
+				// If it's an update
+				path += "/" + fileId;
+				method = 'PUT';
+				etag = localStorage[SYNC_PROVIDER_GDRIVE
+										+ fileId + ".etag"];
+			}
+			var headers = { 'Content-Type' : 'multipart/mixed; boundary="'
+				+ boundary + '"', };
+			if(etag !== undefined) {
+				headers["If-Match"] = etag;
 			}

-			var fileSyncIndex = undefined;
-			var asyncTask = {};
-			asyncTask.run = function() {
-				var boundary = '-------314159265358979323846';
-				var delimiter = "\r\n--" + boundary + "\r\n";
-				var close_delim = "\r\n--" + boundary + "--";
+			var base64Data = core.encodeBase64(content);
+			var multipartRequestBody = delimiter
+				+ 'Content-Type: application/json\r\n\r\n'
+				+ JSON.stringify(metadata) + delimiter + 'Content-Type: '
+				+ contentType + '\r\n'
+				+ 'Content-Transfer-Encoding: base64\r\n' + '\r\n'
+				+ base64Data + close_delim;

-				var contentType = 'text/x-markdown';
-				var metadata = { title : title, mimeType : contentType };
-				if (parentId !== undefined) {
-					// Specify the directory
-					metadata.parents = [ { kind : 'drive#fileLink',
-						id : parentId } ];
+			var request = gapi.client
+				.request({
+					'path' : path,
+					'method' : method,
+					'params' : { 'uploadType' : 'multipart', },
+					'headers' : headers,
+					'body' : multipartRequestBody, });
+			request.execute(function(response) {
+				if (response && response.id) {
+					// Upload success
+					result = response;
+					task.chain();
+					return;
 				}
-				var path = '/upload/drive/v2/files';
-				var method = 'POST';
-				var etag = undefined;
-				if (fileId !== undefined) {
-					// If it's an update
-					path += "/" + fileId;
-					method = 'PUT';
-					etag = localStorage[SYNC_PROVIDER_GDRIVE
-											+ fileId + ".etag"];
-				}
-				var headers = { 'Content-Type' : 'multipart/mixed; boundary="'
-					+ boundary + '"', };
-				if(etag !== undefined) {
-					headers["If-Match"] = etag;
-				}
-
-				var base64Data = core.encodeBase64(content);
-				var multipartRequestBody = delimiter
-					+ 'Content-Type: application/json\r\n\r\n'
-					+ JSON.stringify(metadata) + delimiter + 'Content-Type: '
-					+ contentType + '\r\n'
-					+ 'Content-Transfer-Encoding: base64\r\n' + '\r\n'
-					+ base64Data + close_delim;
-
-				var request = gapi.client
-					.request({
-						'path' : path,
-						'method' : method,
-						'params' : { 'uploadType' : 'multipart', },
-						'headers' : headers,
-						'body' : multipartRequestBody, });
-				request.execute(function(response) {
-					if (response && response.id) {
-						// Upload success
-						fileSyncIndex = SYNC_PROVIDER_GDRIVE + response.id;
-						localStorage[fileSyncIndex + ".etag"] = response.etag;
-						asyncTask.success();
-						return;
+				var error = response.error;
+				// Handle error
+				if(error !== undefined && fileId !== undefined) {
+					if(error.code === 404) {
+						error = 'File ID "' + fileId + '" does not exist on Google Drive.';
 					}
-					var error = response.error;
-					// Handle error
-					if(error !== undefined && fileId !== undefined) {
-						if(error.code === 404) {
-							error = 'File ID "' + fileId + '" does not exist on Google Drive.';
-						}
-						else if(error.code === 412) {
-							// We may have missed a file update
-							localStorage.removeItem("sync.gdrive.lastChangeId");
-							error = 'Conflict on file ID "' + fileId + '". Please restart the synchronization.';
-						}
+					else if(error.code === 412) {
+						// We may have missed a file update
+						localStorage.removeItem("sync.gdrive.lastChangeId");
+						error = 'Conflict on file ID "' + fileId + '". Please restart the synchronization.';
 					}
-					handleError(error, asyncTask, callback);
-				});
-			};
-			asyncTask.onSuccess = function() {
-				callback(fileSyncIndex);
-			};
-			asyncTask.onError = function() {
-				callback();
-			};
-			asyncTaskRunner.addTask(asyncTask);
+				}
+				handleError(error, task, callback);
+			});
 		});
+		task.onSuccess(function() {
+			callback(undefined, result);
+		});
+		task.onError(function(error) {
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};

 	googleHelper.checkUpdates = function(lastChangeId, callback) {
 		callback = callback || core.doNothing;
-		authenticate(function() {
-			if (connected === false) {
-				callback();
-				return;
-			}
+		var changes = [];
+		var newChangeId = lastChangeId || 0;
+		var task = asyncRunner.createTask();
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {
+			var nextPageToken = undefined;
+			function retrievePageOfChanges() {
+				var request = undefined;
+				if(nextPageToken === undefined) {
+					request = gapi.client.drive.changes
+						.list({ 'startChangeId' : newChangeId + 1 });
+				}
+				else {
+					request = gapi.client.drive.changes
+						.list({ 'pageToken' : nextPageToken });
+				}

-			var changes = [];
-			var newChangeId = lastChangeId || 0;
-			function retrievePageOfChanges(request) {
-				var nextPageToken = undefined;
-				var asyncTask = {};
-				asyncTask.run = function() {
-					request.execute(function(response) {
-						if (response && response.largestChangeId) {
-							// Retrieve success
-							newChangeId = response.largestChangeId;
-							nextPageToken = response.nextPageToken;
-							if (response.items !== undefined) {
-								for ( var i = 0; i < response.items.length; i++) {
-									var item = response.items[i];
-									var etag = localStorage[SYNC_PROVIDER_GDRIVE
-										+ item.fileId + ".etag"];
-									if (etag
-										&& (item.deleted === true || item.file.etag != etag)) {
-										changes.push(item);
-									}
-								}
-							}
-							asyncTask.success();
-							return;
-						}
+				request.execute(function(response) {
+					if (!response || !response.largestChangeId) {
 						// Handle error
-						handleError(response.error, asyncTask, callback);
-					});
-				};
-				asyncTask.onSuccess = function() {
-					if (nextPageToken !== undefined) {
-						request = gapi.client.drive.changes
-							.list({ 'pageToken' : nextPageToken });
-						retrievePageOfChanges(request);
-					} else {
-						callback(changes, newChangeId);
+						handleError(response.error, task, callback);
+						return;
 					}
-				};
-				asyncTask.onError = function() {
-					callback();
-				};
-				asyncTaskRunner.addTask(asyncTask);
+					// Retrieve success
+					newChangeId = response.largestChangeId;
+					nextPageToken = response.nextPageToken;
+					if (response.items !== undefined) {
+						for ( var i = 0; i < response.items.length; i++) {
+							var item = response.items[i];
+							var etag = localStorage[SYNC_PROVIDER_GDRIVE
+								+ item.fileId + ".etag"];
+							if (etag
+								&& (item.deleted === true || item.file.etag != etag)) {
+								changes.push(item);
+							}
+						}
+					}
+					if (nextPageToken !== undefined) {
+						task.chain(retrievePageOfChanges);
+					}
+					else {
+						task.chain();
+					}
+				});
 			}
-			var initialRequest = gapi.client.drive.changes
-				.list({ 'startChangeId' : newChangeId + 1 });
-			retrievePageOfChanges(initialRequest);
+			task.chain(retrievePageOfChanges);
 		});
+		task.onSuccess(function() {
+			callback(undefined, changes, newChangeId);
+		});
+		task.onError(function(error) {
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};

-	googleHelper.downloadMetadata = function(ids, callback, result) {
+	googleHelper.downloadMetadata = function(ids, callback) {
 		callback = callback || core.doNothing;
-		result = result || [];
-		if(ids.length === 0) {
-			callback(result);
-			return;
-		}
-		
-		authenticate(function() {
-			if (connected === false) {
-				callback();
-				return;
-			}
-
-			var id = ids.pop();
-			var asyncTask = {};
-			asyncTask.run = function() {
+		var result = [];
+		var task = asyncRunner.createTask();
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {
+			function recursiveDownloadMetadata() {
+				if(ids.length === 0) {
+					task.chain();
+					return;
+				}
+				var id = ids.pop();
 				var token = gapi.auth.getToken();
 				var headers = {
 					Authorization : token ? "Bearer " + token.access_token: null
@ -269,7 +238,7 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 					timeout : AJAX_TIMEOUT
 				}).done(function(data, textStatus, jqXHR) {
 					result.push(data);
-					asyncTask.success();
+					task.chain(recursiveDownloadMetadata);
 				}).fail(function(jqXHR) {
 					var error = {
 						code: jqXHR.status,
@ -279,51 +248,49 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 					if(error.code === 404) {
 						error = 'File ID "' + id + '" does not exist on Google Drive.';
 					}
-					handleError(error, asyncTask, callback);
+					handleError(error, task, callback);
 				});
-			};
-			asyncTask.onSuccess = function() {
-				googleHelper.downloadMetadata(ids, callback, result);
-			};
-			asyncTask.onError = function() {
-				callback();
-			};
-			asyncTaskRunner.addTask(asyncTask);
+			}
+			task.chain(recursiveDownloadMetadata);
 		});
+		task.onSuccess(function() {
+			callback(undefined, result);
+		});
+		task.onError(function(error) {
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};

-	googleHelper.downloadContent = function(objects, callback, result) {
+	googleHelper.downloadContent = function(objects, callback) {
 		callback = callback || core.doNothing;
-		result = result || [];
-		if(objects.length === 0) {
-			callback(result);
-			return;
-		}
-		
-		var object = objects.pop();
-		result.push(object);
-		var file = undefined;
-		// object may be a file
-		if(object.kind == "drive#file") {
-			file = object;
-		}
-		// object may be a change
-		else if(object.kind == "drive#change") {
-			file = object.file;
-		}
-		if(!file) {
-			this.downloadContent(objects, callback, result);
-			return;
-		}
-		
-		authenticate(function() {
-			if (connected === false) {
-				callback();
-				return;
-			}
-			
-			var asyncTask = {};
-			asyncTask.run = function() {
+		var result = [];
+		var task = asyncRunner.createTask();
+		// Add some time for user to choose his files
+		task.timeout = ASYNC_TASK_LONG_TIMEOUT;
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {
+			function recursiveDownloadContent() {
+				if(objects.length === 0) {
+					task.chain();
+					return;
+				}				
+				var object = objects.pop();
+				result.push(object);
+				var file = undefined;
+				// object may be a file
+				if(object.kind == "drive#file") {
+					file = object;
+				}
+				// object may be a change
+				else if(object.kind == "drive#change") {
+					file = object.file;
+				}
+				if(!file) {
+					task.chain(recursiveDownloadContent);
+					return;
+				}
 				var token = gapi.auth.getToken();
 				var headers = {
 					Authorization : token ? "Bearer " + token.access_token: null
@ -335,35 +302,29 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 					timeout : AJAX_TIMEOUT
 				}).done(function(data, textStatus, jqXHR) {
 					file.content = data;
-					asyncTask.success();
+					task.chain(recursiveDownloadContent);
 				}).fail(function(jqXHR) {
 					var error = {
 						code: jqXHR.status,
 						message: jqXHR.statusText
 					};
 					// Handle error
-					handleError(error, asyncTask, callback);
+					handleError(error, task, callback);
 				});
-			};
-			asyncTask.onSuccess = function() {
-				googleHelper.downloadContent(objects, callback, result);
-			};
-			asyncTask.onError = function() {
-				callback();
-			};
-			asyncTaskRunner.addTask(asyncTask);
+			}
+			task.chain(recursiveDownloadContent);
 		});
+		task.onSuccess(function() {
+			callback(undefined, result);
+		});
+		task.onError(function(error) {
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};
 	
-	function handleError(error, asyncTask, callback, serviceName) {
-		serviceName = serviceName || "Google Drive";
+	function handleError(error, task, callback) {
 		var errorMsg = undefined;
-		asyncTask.onError = function() {
-			if (errorMsg !== undefined) {
-				core.showError(errorMsg);
-			}
-			callback();
-		};
 		if (error) {
 			console.error(error);
 			// Try to analyze the error
@ -371,69 +332,55 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 				errorMsg = error;
 			}
 			else if (error.code >= 500 && error.code < 600) {
-				errorMsg = serviceName + " is not accessible.";
 				// Retry as described in Google's best practices
-				asyncTask.retry();
+				task.retry();
 				return;
 			} else if (error.code === 401 || error.code === 403) {
 				authenticated = false;
-				errorMsg = "Access to " + serviceName + " is not authorized.";
+				task.retry();
+				return;
 			} else if (error.code <= 0) {
 				connected = false;
 				authenticated = false;
 				core.setOffline();
 			} else {
-				errorMsg = serviceName + " error (" + error.code + ": "
+				errorMsg = "Google error (" + error.code + ": "
 					+ error.message + ").";
 			}
+			core.showError(errorMsg);
 		}
-		asyncTask.error();
+		task.error(new Error(errorMsg));
 	}

 	var pickerLoaded = false;
-	function loadPicker(callback) {
-		connect(function() {
-			if (connected === false) {
-				pickerLoaded = false;
-				callback();
+	function loadPicker(task) {
+		task.onRun(function() {
+			if (pickerLoaded === true) {
+				task.chain();
 				return;
 			}				
-				
-			var asyncTask = {};
-			asyncTask.run = function() {
-				if (pickerLoaded === true) {
-					asyncTask.success();
-					return;
-				}
-				$.ajax({
-					url : "//www.google.com/jsapi",
-					data : {key: GOOGLE_KEY},
-					dataType : "script", timeout : AJAX_TIMEOUT
-				}).done(function() {
-					asyncTask.success();
-				}).fail(function() {
-					asyncTask.error();
-				});
-			};
-			asyncTask.onSuccess = function() {
-			    google.load('picker', '1', {callback: callback});
+			$.ajax({
+				url : "//www.google.com/jsapi",
+				data : {key: GOOGLE_KEY},
+				dataType : "script", timeout : AJAX_TIMEOUT
+			}).done(function() {
+			    google.load('picker', '1', {callback: task.chain});
 				pickerLoaded = true;
-			};
-			asyncTask.onError = function() {
+			}).fail(function() {
 				core.setOffline();
-				callback();
-			};
-			asyncTaskRunner.addTask(asyncTask);
+				task.error(new Error("Network timeout"));
+			});
 		});
 	}
 	
 	googleHelper.picker = function(callback) {
 		callback = callback || core.doNothing;
-		loadPicker(function() {
-			if (pickerLoaded === false) {
-				callback();
-				return;
-			}
+		var ids = [];
+		var picker = undefined; 
+		var task = asyncRunner.createTask();
+		connect(task);
+		loadPicker(task);
+		task.onRun(function() {			
 			var view = new google.picker.View(google.picker.ViewId.DOCS);
 			view.setMimeTypes("text/x-markdown,text/plain");
 			var pickerBuilder = new google.picker.PickerBuilder();
@ -449,182 +396,122 @@ define(["jquery", "async-runner"], function($, asyncTaskRunner) {
 			pickerBuilder.setCallback(function(data) {
 				if (data.action == google.picker.Action.PICKED ||
 					data.action == google.picker.Action.CANCEL) {
-					var ids = [];
 					if(data.action == google.picker.Action.PICKED) {
 						for(var i=0; i<data.docs.length; i++) {
 					        ids.push(data.docs[i].id);							
 						}
 					}
 					$(".modal-backdrop, .picker").remove();
-					callback(ids);
+					task.chain();
 			    }
 			});
-			var picker = pickerBuilder.build();
+			picker = pickerBuilder.build();
 			$("body").append($("<div>").addClass("modal-backdrop").click(function() {
 				picker.setVisible(false);
 				$(".modal-backdrop, .picker").remove();
-				callback();
+				task.chain();
 			}));
 			picker.setVisible(true);
 		});
-	};
-
-	googleHelper.importFiles = function(ids) {
-		googleHelper.downloadMetadata(ids, function(result) {
-			if(result === undefined) {
-				return;
-			}
-			googleHelper.downloadContent(result, function(result) {
-				if(result === undefined) {
-					return;
-				}
-				for(var i=0; i<result.length; i++) {
-					var file = result[i];
-					fileSyncIndex = SYNC_PROVIDER_GDRIVE + file.id;
-					localStorage[fileSyncIndex + ".etag"] = file.etag;
-					var contentCRC = core.crc32(file.content);
-					localStorage[fileSyncIndex + ".contentCRC"] = contentCRC;
-					var titleCRC = core.crc32(file.title);
-					localStorage[fileSyncIndex + ".titleCRC"] = titleCRC;
-					var fileIndex = fileManager.createFile(file.title, file.content, [fileSyncIndex]);
-					fileManager.selectFile(fileIndex);
-					core.showMessage('"' + file.title + '" imported successfully from Google Drive.');
-				}
-			});
+		task.onSuccess(function() {
+			callback(undefined, ids);
 		});
+		task.onError(function(error) {
+			if(picker !== undefined) {
+				picker.setVisible(false);
+				$(".modal-backdrop, .picker").remove();
+				task.chain();
+			}
+			callback(error);
+		});
+		asyncRunner.addTask(task);
 	};

 	googleHelper.uploadBlogger = function(blogUrl, blogId, postId, title, content, callback) {
-		authenticate(function() {
-			if (connected === false) {
-				callback();
-				return;
-			}
-			
-			var asyncTask = {};
-			asyncTask.run = function() {
-				var token = gapi.auth.getToken();
-				var headers = {
-					Authorization : token ? "Bearer " + token.access_token: null
+		var task = asyncRunner.createTask();
+		connect(task);
+		authenticate(task);
+		task.onRun(function() {
+			var token = gapi.auth.getToken();
+			var headers = {
+				Authorization : token ? "Bearer " + token.access_token: null
+			};				
+			function publish() {
+				var url = "https://www.googleapis.com/blogger/v3/blogs/" + blogId + "/posts/";
+				var data = {
+					kind: "blogger#post",
+					blog: { id: blogId },
+					title: title,
+					content: content
 				};
-				
-				function getBlogId(localCallback) {
-					$.ajax({
-						url : "https://www.googleapis.com/blogger/v3/blogs/byurl",
-						data: { url: blogUrl },
-						headers : headers,
-						dataType : "json",
-						timeout : AJAX_TIMEOUT
-					}).done(function(blog, textStatus, jqXHR) {
-						blogId = blog.id;
-						localCallback();
-					}).fail(function(jqXHR) {
-						var error = {
-							code: jqXHR.status,
-							message: jqXHR.statusText
-						};
-						// Handle error
-						if(error.code === 404) {
-							error = 'Blog "' + blogUrl + '" not found on Blogger.';
-						}
-						handleError(error, asyncTask, callback, "Blogger");
-					});
+				var type = "POST";
+				// If it's an update
+				if(postId !== undefined) {
+					url += postId;
+					data.id = postId;
+					type = "PUT";
 				}
-				
-				function publish() {
-					var url = "https://www.googleapis.com/blogger/v3/blogs/" + blogId + "/posts/";
-					var data = {
-						kind: "blogger#post",
-						blog: { id: blogId },
-						title: title,
-						content: content
+				$.ajax({
+					url : url,
+					data: JSON.stringify(data),
+					headers : headers,
+					type: type,
+					contentType: "application/json",
+					dataType : "json",
+					timeout : AJAX_TIMEOUT
+				}).done(function(post, textStatus, jqXHR) {
+					postId = post.id;
+					task.chain();
+				}).fail(function(jqXHR) {
+					var error = {
+						code: jqXHR.status,
+						message: jqXHR.statusText
 					};
-					var type = "POST";
-					// If it's an update
-					if(postId !== undefined) {
-						url += postId;
-						data.id = postId;
-						type = "PUT";
+					// Handle error
+					if(error.code === 404 && postId !== undefined) {
+						error = 'Post ' + postId + ' not found on Blogger.';
 					}
-					$.ajax({
-						url : url,
-						data: JSON.stringify(data),
-						headers : headers,
-						type: type,
-						contentType: "application/json",
-						dataType : "json",
-						timeout : AJAX_TIMEOUT
-					}).done(function(post, textStatus, jqXHR) {
-						postId = post.id;
-						asyncTask.success();
-					}).fail(function(jqXHR) {
-						var error = {
-							code: jqXHR.status,
-							message: jqXHR.statusText
-						};
-						// Handle error
-						if(error.code === 404 && postId !== undefined) {
-							error = 'Post ' + postId + ' not found on Blogger.';
-						}
-						handleError(error, asyncTask, callback, "Blogger");
-					});
+					handleError(error, task, callback);
+				});
+			}
+			function getBlogId() {
+				if(blogId !== undefined) {
+					task.chain(publish);
 				}
-				
-				if(blogId === undefined) {
-					getBlogId(publish);
-				}
-				else {
-					publish();
-				}
-			};
-			asyncTask.onSuccess = function() {
-				callback(blogId, postId);
-			};
-			asyncTask.onError = function() {
-				callback();
-			};
-			asyncTaskRunner.addTask(asyncTask);
+				$.ajax({
+					url : "https://www.googleapis.com/blogger/v3/blogs/byurl",
+					data: { url: blogUrl },
+					headers : headers,
+					dataType : "json",
+					timeout : AJAX_TIMEOUT
+				}).done(function(blog, textStatus, jqXHR) {
+					blogId = blog.id;
+					task.chain(publish);
+				}).fail(function(jqXHR) {
+					var error = {
+						code: jqXHR.status,
+						message: jqXHR.statusText
+					};
+					// Handle error
+					if(error.code === 404) {
+						error = 'Blog "' + blogUrl + '" not found on Blogger.';
+					}
+					handleError(error, task, callback);
+				});
+			}
+			task.chain(getBlogId);
 		});
+		task.onSuccess = function() {
+			callback(undefined, blogId, postId);
+		};
+		task.onError = function(error) {
+			callback(error);
+		};
+		asyncRunner.addTask(task);
 	};

-	googleHelper.init = function(coreModule, fileManagerModule) {
+	googleHelper.init = function(coreModule) {
 		core = coreModule;
-		fileManager = fileManagerModule;
-		var state = localStorage["sync.gdrive.state"];
-		if(state === undefined) {
-			return;
-		}
-		localStorage.removeItem("sync.gdrive.state");
-		state = JSON.parse(state);
-		if (state.action == "create") {
-			googleHelper.upload(undefined, state.folderId, GDRIVE_DEFAULT_FILE_TITLE,
-				"", function(fileSyncIndex) {
-				if(fileSyncIndex === undefined) {
-					return;
-				}
-				var contentCRC = core.crc32("");
-				localStorage[fileSyncIndex + ".contentCRC"] = contentCRC;
-				var titleCRC = core.crc32(GDRIVE_DEFAULT_FILE_TITLE);
-				localStorage[fileSyncIndex + ".titleCRC"] = titleCRC;
-				var fileIndex = fileManager.createFile(GDRIVE_DEFAULT_FILE_TITLE, "", [fileSyncIndex]);
-				fileManager.selectFile(fileIndex);
-				core.showMessage('"' + GDRIVE_DEFAULT_FILE_TITLE + '" created successfully on Google Drive.');
-			});
-		}
-		else if (state.action == "open") {
-			var ids = [];
-			for(var i=0; i<state.ids.length; i++) {
-				var id = state.ids[i];
-				var fileSyncIndex = SYNC_PROVIDER_GDRIVE + id;
-				var fileIndex = fileManager.getFileIndexFromSync(fileSyncIndex);
-				if(fileIndex !== undefined) {
-					fileManager.selectFile(fileIndex);
-				} else {
-					ids.push(id);
-				}
-			}
-			googleHelper.importFiles(ids);
-		}
 	};
 	
 	return googleHelper;
--- a/js/publisher.js
+++ b/js/publisher.js
@ -1,4 +1,4 @@
-define(["jquery", "github-provider", "blogger-provider", "dropbox-provider", "underscore"], function($) {
+define(["jquery", "github-provider", "blogger-provider", "dropbox-provider", "gdrive-provider", "underscore"], function($) {
 	
 	// Dependencies
 	var core = undefined;
@ -183,8 +183,7 @@ define(["jquery", "github-provider", "blogger-provider", "dropbox-provider", "un
 			$(".msg-no-publish").removeClass("hide");
 		}
 		_.each(publishIndexList, function(publishIndex) {
-			var serializedObject = localStorage[publishIndex];
-			var publishAttributes = JSON.parse(serializedObject);
+			var publishAttributes = JSON.parse(localStorage[publishIndex]);
 			var publishDesc = JSON.stringify(publishAttributes).replace(/{|}|"/g, "");
 			lineElement = $(_.template(lineTemplate, {
 				provider: providerMap[publishAttributes.provider],
@ -203,7 +202,7 @@ define(["jquery", "github-provider", "blogger-provider", "dropbox-provider", "un
 		
 		// Init each provider
 		_.each(providerMap, function(provider) {
-			provider.init(core);
+			provider.init(core, fileManager);
 			// Publish provider button
 			$(".action-publish-" + provider.providerId).click(function() {
 				initNewLocation(provider);
--- a/js/synchronizer.js
+++ b/js/synchronizer.js
@ -1,10 +1,16 @@
-define(["jquery", "google-helper", "dropbox-helper"], function($, googleHelper, dropboxHelper) {
+define(["jquery", "google-helper", "dropbox-helper", "dropbox-provider", "gdrive-provider"], function($, googleHelper, dropboxHelper) {
 	var synchronizer = {};
 	
 	// Dependencies
 	var core = undefined;
 	var fileManager = undefined;

+	// Create a map with providerName: providerObject
+	var providerMap = _.chain(arguments)
+		.map(function(argument) {
+			return argument && argument.providerType & PROVIDER_TYPE_SYNC_FLAG && [argument.providerId, argument];
+		}).compact().object().value();
+
 	// Used to know the providers we are connected to 
 	synchronizer.useGoogleDrive = false;
 	synchronizer.useDropbox = false;
@ -52,15 +58,12 @@ define(["jquery", "google-helper", "dropbox-helper"], function($, googleHelper,
 		}
 		
 		// Dequeue a synchronized location
-		var fileSyncIndex = uploadFileSyncIndexList.pop();
-		if(!fileSyncIndex) {
-			locationUp(callback);
-			return;
-		}
-
-		// Skip if CRC has not changed
+		var syncIndex = uploadFileSyncIndexList.pop();
+		var syncAttributes = JSON.parse(localStorage[fileSyncIndex]);
+		=
 		var syncContentCRC = localStorage[fileSyncIndex + ".contentCRC"];
 		var syncTitleCRC = localStorage[fileSyncIndex + ".titleCRC"];
+		// Skip if CRC has not changed
 		if(uploadContentCRC == syncContentCRC && (syncTitleCRC === undefined || uploadTitleCRC == syncTitleCRC)) {
 			locationUp(callback);
 			return;
@ -74,17 +77,15 @@ define(["jquery", "google-helper", "dropbox-helper"], function($, googleHelper,
 		// Try to find the provider
 		if (fileSyncIndex.indexOf(SYNC_PROVIDER_GDRIVE) === 0) {
 			var id = fileSyncIndex.substring(SYNC_PROVIDER_GDRIVE.length);
-			googleHelper.upload(id, undefined, uploadTitle, uploadContent, function(result) {
-				if (result !== undefined) {
-					localStorage[fileSyncIndex + ".contentCRC"] = uploadContentCRC;
-					localStorage[fileSyncIndex + ".titleCRC"] = uploadTitleCRC;
-					locationUp(callback);
+			googleHelper.upload(id, undefined, uploadTitle, uploadContent, function(error, result) {
+				if(error) {
+					// If error we abort the synchronization (retry later)
+					callback(error);
 					return;
 				}
-				
-				// If error we abort the synchronization (retry later)
-				callback("abort");
-				return;
+				localStorage[fileSyncIndex + ".contentCRC"] = uploadContentCRC;
+				localStorage[fileSyncIndex + ".titleCRC"] = uploadTitleCRC;
+				locationUp(callback);
 			});
 		} else if (fileSyncIndex.indexOf(SYNC_PROVIDER_DROPBOX) === 0) {
 			var path = fileSyncIndex.substring(SYNC_PROVIDER_DROPBOX.length);
@ -130,7 +131,7 @@ define(["jquery", "google-helper", "dropbox-helper"], function($, googleHelper,
 		uploadTitleCRC = core.crc32(uploadTitle);

 		// Parse the list of synchronized locations associated to the document
-		uploadFileSyncIndexList = fileSyncIndexes.split(";");
+		uploadFileSyncIndexList = _.compact(fileSyncIndexes.split(";"));
 		locationUp(callback);
 	}

@ -156,14 +157,14 @@ define(["jquery", "google-helper", "dropbox-helper"], function($, googleHelper,
 		}
 		var lastChangeId = parseInt(localStorage[SYNC_PROVIDER_GDRIVE
 			+ "lastChangeId"]);
-		googleHelper.checkUpdates(lastChangeId, function(changes, newChangeId) {
-			if (changes === undefined) {
-				callback("error");
+		googleHelper.checkUpdates(lastChangeId, function(error, changes, newChangeId) {
+			if (error) {
+				callback(error);
 				return;
 			}
-			googleHelper.downloadContent(changes, function(changes) {
-				if (changes === undefined) {
-					callback("error");
+			googleHelper.downloadContent(changes, function(error, changes) {
+				if (error) {
+					callback(error);
 					return;
 				}
 				var updateFileTitles = false;
@ -336,10 +337,83 @@ define(["jquery", "google-helper", "dropbox-helper"], function($, googleHelper,
 		});
 	};
 	
+	// Used to populate the "Manage synchronization" dialog
+	var lineTemplate = ['<div class="input-prepend input-append">',
+		'<span class="add-on" title="<%= provider.providerName %>">',
+		'<i class="icon-<%= provider.providerId %>"></i></span>',
+		'<input class="span5" type="text" value="<%= syncDesc %>" disabled />',
+		'</div>'].join("");
+	var removeButtonTemplate = '<a class="btn" title="Remove this location"><i class="icon-trash"></i></a>';
+	synchronizer.refreshManageSync = function() {
+		var fileIndex = fileManager.getCurrentFileIndex();
+		var syncIndexList = _.compact(localStorage[fileIndex + ".sync"].split(";"));
+		$(".msg-no-sync, .msg-sync-list").addClass("hide");
+		$("#manage-sync-list .input-append").remove();
+		if (syncIndexList.length > 0) {
+			$(".msg-sync-list").removeClass("hide");
+		} else {
+			$(".msg-no-sync").removeClass("hide");
+		}
+		_.each(syncIndexList, function(syncIndex) {
+			var syncAttributes = JSON.parse(localStorage[syncIndex]);
+			var syncDesc = syncAttributes.id || syncAttributes.path;
+			lineElement = $(_.template(lineTemplate, {
+				provider: providerMap[syncAttributes.provider],
+				syncDesc: syncDesc
+			}));
+			lineElement.append($(removeButtonTemplate).click(function() {
+				fileManager.removeSync(syncIndex);
+				fileManager.updateFileTitles();
+			}));
+			$("#manage-sync-list").append(lineElement);
+		});
+	};
+	
 	synchronizer.init = function(coreModule, fileManagerModule) {
 		core = coreModule;
 		fileManager = fileManagerModule;
 		
+		// Init each provider
+		_.each(providerMap, function(provider) {
+			provider.init(core, fileManager);
+			// Provider's import button
+			$(".action-sync-import-" + provider.providerId).click(function(event) {
+				provider.importFiles(event);
+			});
+			// Provider's export button
+			$(".action-sync-export-" + provider.providerId).click(function(event) {
+				var fileIndex = fileManager.getCurrentFileIndex();
+				var title = localStorage[fileIndex + ".title"];
+				var content = localStorage[fileIndex + ".content"];
+				provider.exportFile(event, title, content, function(error, syncIndex) {
+					if(error) {
+						return;
+					}
+					localStorage[fileIndex + ".sync"] += syncIndex + ";";
+					synchronizer.refreshManageSync();
+					fileManager.updateFileTitles();
+					core.showMessage('"' + title
+						+ '" will now be synchronized on ' + provider.providerName + '.');
+				});
+			});
+			// Provider's manual sync button
+			$(".action-sync-manual-" + provider.providerId).click(function(event) {
+				var fileIndex = fileManager.getCurrentFileIndex();
+				var title = localStorage[fileIndex + ".title"];
+				var content = localStorage[fileIndex + ".content"];
+				provider.exportManual(event, title, content, function(error, syncIndex) {
+					if(error) {
+						return;
+					}
+					localStorage[fileIndex + ".sync"] += syncIndex + ";";
+					synchronizer.refreshManageSync();
+					fileManager.updateFileTitles();
+					core.showMessage('"' + title
+						+ '" will now be synchronized on ' + provider.providerName + '.');
+				});
+			});
+		});
+		
 		synchronizer.updateSyncButton();
 		$(".action-force-sync").click(function() {
 			if(!$(this).hasClass("disabled")) {