feat(base64-wrapping): support for wrapping base64 strings

Wrapping base64 strings, which are usually extremely long lines of text, is now supported.
Newlines can be added arbitrarily, as long as they appear after the comma (,) character.

Closes #429

Author: tivie

dist/showdown.js

@@ -1,6 +1,6 @@
 {
   "name": "showdown",
-  "version": "1.7.3",
+  "version": "1.7.4",
   "description": "A Markdown to HTML converter written in Javascript",
   "author": "Estevão Santos",
   "homepage": "http://showdownjs.github.io/showdown/",

dist/showdown.js.map

@@ -8,9 +8,15 @@ showdown.subParser('images', function (text, options, globals) {
 
   var inlineRegExp      = /!\[([^\]]*?)][ \t]*()\([ \t]?<?([\S]+?(?:\([\S]*?\)[\S]*?)?)>?(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*(?:(["'])([^"]*?)\6)?[ \t]?\)/g,
       crazyRegExp       = /!\[([^\]]*?)][ \t]*()\([ \t]?<([^>]*)>(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*(?:(?:(["'])([^"]*?)\6))?[ \t]?\)/g,
-      referenceRegExp   = /!\[([^\]]*?)] ?(?:\n *)?\[(.*?)]()()()()()/g,
+      base64RegExp      = /!\[([^\]]*?)][ \t]*()\([ \t]?<?(data:.+?\/.+?;base64,[A-Za-z0-9+/=\n]+?)>?(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*(?:(["'])([^"]*?)\6)?[ \t]?\)/g,
+      referenceRegExp   = /!\[([^\]]*?)] ?(?:\n *)?\[([\s\S]*?)]()()()()()/g,
       refShortcutRegExp = /!\[([^\[\]]+)]()()()()()/g;
 
+  function writeImageTagBase64 (wholeMatch, altText, linkId, url, width, height, m5, title) {
+    url = url.replace(/\s/g, '');
+    return writeImageTag (wholeMatch, altText, linkId, url, width, height, m5, title);
+  }
+
   function writeImageTag (wholeMatch, altText, linkId, url, width, height, m5, title) {
 
     var gUrls   = globals.gUrls,
@@ -80,13 +86,17 @@ showdown.subParser('images', function (text, options, globals) {
   text = text.replace(referenceRegExp, writeImageTag);
 
   // Next, handle inline images:  ![alt text](url =<width>x<height> "optional title")
+
+  // base64 encoded images
+  text = text.replace(base64RegExp, writeImageTagBase64);
+
   // cases with crazy urls like ./image/cat1).png
   text = text.replace(crazyRegExp, writeImageTag);
 
   // normal cases
   text = text.replace(inlineRegExp, writeImageTag);
 
-  // handle reference-style shortcuts: |[img text]
+  // handle reference-style shortcuts: ![img text]
   text = text.replace(refShortcutRegExp, writeImageTag);
 
   text = globals.converter._dispatch('images.after', text, options, globals);

dist/showdown.min.js

@@ -6,14 +6,20 @@
 showdown.subParser('stripLinkDefinitions', function (text, options, globals) {
   'use strict';
 
-  var regex = /^ {0,3}\[(.+)]:[ \t]*\n?[ \t]*<?([^>\s]+)>?(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*\n?[ \t]*(?:(\n*)["|'(](.+?)["|')][ \t]*)?(?:\n+|(?=¨0))/gm;
+  var regex       = /^ {0,3}\[(.+)]:[ \t]*\n?[ \t]*<?([^>\s]+)>?(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*\n?[ \t]*(?:(\n*)["|'(](.+?)["|')][ \t]*)?(?:\n+|(?=¨0))/gm,
+      base64Regex = /^ {0,3}\[(.+)]:[ \t]*\n?[ \t]*<?(data:.+?\/.+?;base64,[A-Za-z0-9+/=\n]+?)>?(?: =([*\d]+[A-Za-z%]{0,4})x([*\d]+[A-Za-z%]{0,4}))?[ \t]*\n?[ \t]*(?:(\n*)["|'(](.+?)["|')][ \t]*)?(?:\n\n|(?=¨0)|(?=\n\[))/gm;
 
   // attacklab: sentinel workarounds for lack of \A and \Z, safari\khtml bug
   text += '¨0';
 
-  text = text.replace(regex, function (wholeMatch, linkId, url, width, height, blankLines, title) {
+  var replaceFunc = function (wholeMatch, linkId, url, width, height, blankLines, title) {
     linkId = linkId.toLowerCase();
-    globals.gUrls[linkId] = showdown.subParser('encodeAmpsAndAngles')(url, options, globals);  // Link IDs are case-insensitive
+    if (url.match(/^data:.+?\/.+?;base64,/)) {
+      // remove newlines
+      globals.gUrls[linkId] = url.replace(/\s/g, '');
+    } else {
+      globals.gUrls[linkId] = showdown.subParser('encodeAmpsAndAngles')(url, options, globals);  // Link IDs are case-insensitive
+    }
 
     if (blankLines) {
       // Oops, found blank lines, so it's not a title.
@@ -33,7 +39,12 @@ showdown.subParser('stripLinkDefinitions', function (text, options, globals) {
     }
     // Completely remove the definition from the text
     return '';
-  });
+  };
+
+  // first we try to find base64 link references
+  text = text.replace(base64Regex, replaceFunc);
+
+  text = text.replace(regex, replaceFunc);
 
   // attacklab: strip sentinel
   text = text.replace(/¨0/, '');

dist/showdown.min.js.map

@@ -0,0 +1,3 @@
+<p><img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAQAAAADCAIAAAA7ljmRAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAYSURBVBhXYwCC/2AAZYEoOAMs8Z+BgQEAXdcR7/Q1gssAAAAASUVORK5CYII=" alt="foo" /></p>
+<p><img src="data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAQAAAADCAIAAAA7ljmRAAAAAXNSR0IArs4c6QAAAARnQU1BAACxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAYSURBVBhXYwCC/2AAZYEoOAMs8Z+BgQEAXdcR7/Q1gssAAAAASUVORK5CYII=" alt="bar" /></p>
+

package.json

@@ -0,0 +1,9 @@
+![foo](data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAQAAAADCAIAAAA7ljmRAAAAAXNSR0IArs4c6QAAAARnQU1BAA
+Cxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAYSURBVBhXYwCC/2AAZYEoOAMs8Z+BgQEAXdcR7/Q1gssAAAAASUVORK5CYII=)
+
+![bar][]
+
+
+[bar]:
+data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAQAAAADCAIAAAA7ljmRAAAAAXNSR0IArs4c6QAAAARnQU1BAA
+Cxjwv8YQUAAAAJcEhZcwAADsMAAA7DAcdvqGQAAAAYSURBVBhXYwCC/2AAZYEoOAMs8Z+BgQEAXdcR7/Q1gssAAAAASUVORK5CYII=