109 lines
3.8 KiB
JavaScript
109 lines
3.8 KiB
JavaScript
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(function () {
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var output, Converter;
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if (typeof exports === "object" && typeof require === "function") { // we're in a CommonJS (e.g. Node.js) module
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output = exports;
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Converter = require("./Markdown.Converter").Converter;
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} else {
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output = window.Markdown;
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Converter = output.Converter;
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}
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output.getSanitizingConverter = function () {
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var converter = new Converter();
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converter.hooks.chain("postConversion", sanitizeHtml);
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converter.hooks.chain("postConversion", balanceTags);
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return converter;
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}
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function sanitizeHtml(html) {
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return html.replace(/<[^>]*>?/gi, sanitizeTag);
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}
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// (tags that can be opened/closed) | (tags that stand alone)
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var basic_tag_whitelist = /^(<\/?(b|blockquote|code|del|dd|dl|dt|em|h1|h2|h3|i|kbd|li|ol|p|pre|s|sup|sub|strong|strike|ul)>|<(br|hr)\s?\/?>)$/i;
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// <a href="url..." optional title>|</a>
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var a_white = /^(<a\shref="((https?|ftp):\/\/|\/)[-A-Za-z0-9+&@#\/%?=~_|!:,.;\(\)]+"(\stitle="[^"<>]+")?\s?>|<\/a>)$/i;
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// <img src="url..." optional width optional height optional alt optional title
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var img_white = /^(<img\ssrc="(https?:\/\/|\/)[-A-Za-z0-9+&@#\/%?=~_|!:,.;\(\)]+"(\swidth="\d{1,3}")?(\sheight="\d{1,3}")?(\salt="[^"<>]*")?(\stitle="[^"<>]*")?\s?\/?>)$/i;
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function sanitizeTag(tag) {
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if (tag.match(basic_tag_whitelist) || tag.match(a_white) || tag.match(img_white))
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return tag;
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else
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return "";
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}
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/// <summary>
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/// attempt to balance HTML tags in the html string
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/// by removing any unmatched opening or closing tags
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/// IMPORTANT: we *assume* HTML has *already* been
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/// sanitized and is safe/sane before balancing!
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///
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/// adapted from CODESNIPPET: A8591DBA-D1D3-11DE-947C-BA5556D89593
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/// </summary>
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function balanceTags(html) {
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if (html == "")
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return "";
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var re = /<\/?\w+[^>]*(\s|$|>)/g;
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// convert everything to lower case; this makes
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// our case insensitive comparisons easier
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var tags = html.toLowerCase().match(re);
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// no HTML tags present? nothing to do; exit now
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var tagcount = (tags || []).length;
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if (tagcount == 0)
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return html;
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var tagname, tag;
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var ignoredtags = "<p><img><br><li><hr>";
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var match;
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var tagpaired = [];
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var tagremove = [];
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var needsRemoval = false;
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// loop through matched tags in forward order
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for (var ctag = 0; ctag < tagcount; ctag++) {
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tagname = tags[ctag].replace(/<\/?(\w+).*/, "$1");
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// skip any already paired tags
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// and skip tags in our ignore list; assume they're self-closed
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if (tagpaired[ctag] || ignoredtags.search("<" + tagname + ">") > -1)
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continue;
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tag = tags[ctag];
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match = -1;
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if (!/^<\//.test(tag)) {
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// this is an opening tag
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// search forwards (next tags), look for closing tags
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for (var ntag = ctag + 1; ntag < tagcount; ntag++) {
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if (!tagpaired[ntag] && tags[ntag] == "</" + tagname + ">") {
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match = ntag;
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break;
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}
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}
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}
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if (match == -1)
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needsRemoval = tagremove[ctag] = true; // mark for removal
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else
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tagpaired[match] = true; // mark paired
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}
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if (!needsRemoval)
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return html;
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// delete all orphaned tags from the string
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var ctag = 0;
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html = html.replace(re, function (match) {
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var res = tagremove[ctag] ? "" : match;
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ctag++;
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return res;
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});
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return html;
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}
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})();
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