Merge pull request #73 from twitter/derekmooney-gh-pages

Derekmooney gh pages

README.md

@@ -148,6 +148,7 @@ Here the list of properties accepted by the optional object that could be passed
 ```js
   {
     callback: Function,   // default the common replacer
+    attributes: Function, // default returns {}
     base: string,         // default MaxCDN
     ext: string,          // default ".png"
     className: string,    // default "emoji"
@@ -173,6 +174,19 @@ function imageSourceGenerator(icon, options) {
 }
 ```
 
+##### attributes
+The function to invoke in order to generate additional, custom attributes for the image tag.
+
+By default it is a function like the following one:
+```js
+function attributesCallback(icon, variant) {
+  return {
+    title: 'Emoji: ' + icon + variant
+  };
+}
+```
+
+Event handlers cannot be specified via this method, and twemoji-provided attributes (src, alt, className, draggable) cannot be re-defined.
 
 ##### base
 The default url is the same as `twemoji.base`, so if you modify the former, it will reflect as default for all parsed strings or nodes.

test.js

@@ -306,6 +306,102 @@ wru.test([{
       div.getElementsByTagName('img')[0].className === className
     );
   }
+},{
+  name: 'string parsing + attributes callback',
+  test: function () {
+    wru.assert(
+      'custom attributes are inserted',
+      'I <img class="emoji" draggable="false" alt="\u2764" src="' + base + '36x36/2764.png" title="Emoji: \u2764" data-test="We all &lt;3 emoji"> emoji!' ===
+      twemoji.parse(
+        'I \u2764 emoji!',
+        {
+          attributes: function(icon) {
+            return {
+              title: 'Emoji: ' + icon,
+              'data-test': 'We all <3 emoji'
+            };
+          }
+        }
+      )
+    );
+  }
+},{
+  name: 'string parsing + attributes callback content properly encoded',
+  test: function () {
+    wru.assert(
+      'custom attributes are inserted',
+      'I <img class="emoji" draggable="false" alt="\u2764" src="' + base + '36x36/2764.png" title="&amp;amp;lt;script&amp;amp;gt;alert(&quot;yo&quot;)&amp;amp;lt;/script&amp;amp;gt;"> emoji!' ===
+      twemoji.parse(
+        'I \u2764 emoji!',
+        {
+          attributes: function(icon) {
+            return {
+              title: '&amp;lt;script&amp;gt;alert("yo")&amp;lt;/script&amp;gt;'
+            };
+          }
+        }
+      )
+    );
+  }
+},{
+  name: 'string parsing + attributes callback "on" attributes are omitted',
+  test: function () {
+    wru.assert(
+      'custom attributes are inserted',
+      'I <img class="emoji" draggable="false" alt="❤" src="' + base + '36x36/2764.png" title="test"> emoji!' ===
+      twemoji.parse(
+        'I \u2764 emoji!',
+        {
+          attributes: function(icon) {
+            return {
+              title: 'test',
+              onsomething: 'whoops!',
+              onclick: 'nope',
+              onmousedown: 'nada'
+            };
+          }
+        }
+      )
+    );
+  }
+},{    
+  name: 'DOM parsing + attributes callback',
+  test: function () {
+    var img,
+    // without variant
+        div = document.createElement('div');
+    div.appendChild(document.createTextNode('I \u2764 emoji!'));
+    twemoji.parse(
+      div, { 
+        attributes: function(icon) { 
+          return { 
+            title: 'Emoji: ' + icon,
+            'data-test': 'We all <3 emoji',
+            onclick: 'nope',
+            onmousedown: 'nada'
+          }; 
+        }
+      }
+     
+    );    
+    wru.assert('default parsing works creating 3 nodes', div.childNodes.length === 3);
+    wru.assert('first child is the expected one', div.removeChild(div.firstChild).nodeValue === 'I ');
+    img = div.removeChild(div.firstChild);
+    wru.assert('second child is the image', img.nodeName === 'IMG');
+    wru.assert('img attributes are OK',
+      img.className === 'emoji' &&
+      img.getAttribute('draggable') === 'false' &&
+      img.src === base + '36x36/2764.png' &&
+      img.alt === '\u2764' &&
+      img.onerror === twemoji.onerror &&
+      img.getAttribute('title') === 'Emoji: \u2764' &&
+      img.getAttribute('data-test') === 'We all <3 emoji'
+    );
+    wru.assert('img on attributes are omitted',
+      img.onclick === null &&
+      img.onmousedown === null
+    );  
+  }
 },{
   name: 'folder option',
   test: function () {

twemoji-generator.js

@@ -500,10 +500,22 @@ function createTwemoji(re) {
           test: test
         },
 
+        // used to escape HTML special chars in attributes
+        escaper = {
+          '&': '&',
+          '<': '&lt;',
+          '>': '&gt;',
+          "'": '&#39;',
+          '"': '&quot;'
+        },
+
         // RegExp based on emoji's official Unicode standards
         // http://www.unicode.org/Public/UNIDATA/EmojiSources.txt
         re = /twemoji/,
 
+        // used to find HTML special chars in attributes
+        rescaper = /[&<>'"]/g,
+
         // nodes with type 1 which should **not** be parsed
         shouldntBeParsed = /IFRAME|NOFRAMES|NOSCRIPT|SCRIPT|SELECT|STYLE|TEXTAREA/,
 
@@ -527,6 +539,15 @@ function createTwemoji(re) {
         return document.createTextNode(text);
       }
 
+      /**
+       * Utility function to escape html attribute text
+       * @param   string  text use in HTML attribute
+       * @return  string  text encoded to use in HTML attribute
+       */
+      function escapeHTML(s) {
+        return s.replace(rescaper, replacer);
+      }
+
       /**
        * Default callback used to generate emoji src
        *  based on Twitter CDN
@@ -604,6 +625,8 @@ function createTwemoji(re) {
         var
           allText = grabAllTextNodes(node, []),
           length = allText.length,
+          attrib,
+          attrname,
           modified,
           fragment,
           subnode,
@@ -642,8 +665,19 @@ function createTwemoji(re) {
               if (src) {
                 img = new Image();
                 img.onerror = twemoji.onerror;
-                img.className = options.className;
                 img.setAttribute('draggable', 'false');
+                attrib = options.attributes(icon, variant);
+                for (attrname in attrib) {
+                  if (
+                    attrib.hasOwnProperty(attrname) &&
+                    // don't allow any handlers to be set + don't allow overrides
+                    attrname.indexOf('on') !== 0 &&
+                    !img.hasAttribute(attrname)
+                  ) {
+                    img.setAttribute(attrname, attrib[attrname]);
+                  }
+                }
+                img.className = options.className;
                 img.alt = alt;
                 img.src = src;
                 modified = true;
@@ -684,7 +718,11 @@ function createTwemoji(re) {
        */
       function parseString(str, options) {
         return replace(str, function (match, icon, variant) {
-          var src;
+          var
+            ret = match,
+            attrib,
+            attrname,
+            src;
           // verify the variant is not the FE0E one
           // this variant means "emoji as text" and should not
           // require any action/replacement
@@ -698,7 +736,7 @@ function createTwemoji(re) {
             if (src) {
               // recycle the match string replacing the emoji
               // with its image counter part
-              match = '<img '.concat(
+              ret = '<img '.concat(
                 'class="', options.className, '" ',
                 'draggable="false" ',
                 // needs to preserve user original intent
@@ -708,15 +746,43 @@ function createTwemoji(re) {
                 '"',
                 ' src="',
                 src,
-                '"',
+                '"'
-                '>'
               );
+              attrib = options.attributes(icon, variant);
+              for (attrname in attrib) { 
+                if (
+                  attrib.hasOwnProperty(attrname) &&
+                  // don't allow any handlers to be set + don't allow overrides
+                  attrname.indexOf('on') !== 0 &&
+                  ret.indexOf(' ' + attrname + '=') === -1
+                ) {
+                  ret = ret.concat(' ', attrname, '="', escapeHTML(attrib[attrname]), '"');
                 }
               }
-          return match;
+              ret = ret.concat('>');
+            }
+          }
+          return ret;
         });
       }
 
+      /**
+       * Function used to actually replace HTML special chars
+       * @param   string  HTML special char
+       * @return  string  encoded HTML special char
+       */
+      function replacer(m) {
+        return escaper[m];
+      }
+
+      /**
+       * Default options.attribute callback
+       * @return  null
+       */
+      function returnNull() {
+        return null;
+      }
+
       /**
        * Given a generic value, creates its squared counterpart if it's a number.
        *  As example, number 36 will return '36x36'.
@@ -758,6 +824,7 @@ function createTwemoji(re) {
         // otherwise use the DOM tree and parse text nodes only
         return (typeof what === 'string' ? parseString : parseNode)(what, {
           callback:   how.callback || defaultImageSrcGenerator,
+          attributes: typeof how.attributes === 'function' ? how.attributes : returnNull,
           base:       typeof how.base === 'string' ? how.base : twemoji.base,
           ext:        how.ext || twemoji.ext,
           size:       how.folder || toSizeSquaredAsset(how.size || twemoji.size),