Stackedit/js/async-runner.js
2013-03-30 18:38:18 +00:00

71 lines
1.7 KiB
JavaScript

/**
* Used to run any asynchronous tasks sequentially (ajax mainly)
* An asynchronous task must be created with:
* - a run() function (required) that may call success() or error()
* - a onSuccess() function (optional)
* - a onError() function (optional)
*/
var asyncTaskRunner = (function() {
var asyncTaskRunner = {};
var asyncTaskQueue = [];
var currentTask = undefined;
var currentTaskStartTime = new Date().getTime();
// Run the next task in the queue if any and no other is running
asyncTaskRunner.runTask = function() {
// If there is a task currently running
if(currentTask !== undefined) {
// If the current task takes too long
if(currentTaskStartTime + 30000 < currentTime) {
currentTask.error();
}
return;
}
// If no task in the queue
if(asyncTaskQueue.length === 0) {
return;
}
currentTask = asyncTaskQueue.shift();
currentTaskStartTime = currentTime;
showWorkingIndicator(true);
// Set task attributes and functions
currentTask.finished = false;
currentTask.finish = function() {
this.finished = true;
showWorkingIndicator(false);
currentTask = undefined;
asyncTaskRunner.runTask();
};
currentTask.success = function() {
if(this.finished === true) {
return;
}
if(this.onSuccess) {
this.onSuccess();
}
this.finish();
};
currentTask.error = function() {
if(this.finished === true) {
return;
}
if(this.onError) {
this.onError();
}
this.finish();
};
currentTask.run();
};
// Add a task in the queue
asyncTaskRunner.addTask = function(asyncTask) {
asyncTaskQueue.push(asyncTask);
};
return asyncTaskRunner;
})();