refactor($compile): move img[srcset] sanitizing to helper method

src/ng/compile.js

@@ -1631,6 +1631,57 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
     }
 
 
+    function sanitizeSrcset(value) {
+      if (!value) {
+        return value;
+      }
+      if (!isString(value)) {
+        throw $compileMinErr('srcset', 'Can\'t pass trusted values to `$set(\'srcset\', value)`: "{0}"', value.toString());
+      }
+
+      // Such values are a bit too complex to handle automatically inside $sce.
+      // Instead, we sanitize each of the URIs individually, which works, even dynamically.
+
+      // It's not possible to work around this using `$sce.trustAsMediaUrl`.
+      // If you want to programmatically set explicitly trusted unsafe URLs, you should use
+      // `$sce.trustAsHtml` on the whole `img` tag and inject it into the DOM using the
+      // `ng-bind-html` directive.
+
+      var result = '';
+
+      // first check if there are spaces because it's not the same pattern
+      var trimmedSrcset = trim(value);
+      //                (   999x   ,|   999w   ,|   ,|,   )
+      var srcPattern = /(\s+\d+x\s*,|\s+\d+w\s*,|\s+,|,\s+)/;
+      var pattern = /\s/.test(trimmedSrcset) ? srcPattern : /(,)/;
+
+      // split srcset into tuple of uri and descriptor except for the last item
+      var rawUris = trimmedSrcset.split(pattern);
+
+      // for each tuples
+      var nbrUrisWith2parts = Math.floor(rawUris.length / 2);
+      for (var i = 0; i < nbrUrisWith2parts; i++) {
+        var innerIdx = i * 2;
+        // sanitize the uri
+        result += $sce.getTrustedMediaUrl(trim(rawUris[innerIdx]));
+        // add the descriptor
+        result += ' ' + trim(rawUris[innerIdx + 1]);
+      }
+
+      // split the last item into uri and descriptor
+      var lastTuple = trim(rawUris[i * 2]).split(/\s/);
+
+      // sanitize the last uri
+      result += $sce.getTrustedMediaUrl(trim(lastTuple[0]));
+
+      // and add the last descriptor if any
+      if (lastTuple.length === 2) {
+        result += (' ' + trim(lastTuple[1]));
+      }
+      return result;
+    }
+
+
     function Attributes(element, attributesToCopy) {
       if (attributesToCopy) {
         var keys = Object.keys(attributesToCopy);
@@ -1767,51 +1818,8 @@ function $CompileProvider($provide, $$sanitizeUriProvider) {
         nodeName = nodeName_(this.$$element);
 
         // Sanitize img[srcset] values.
-        if (nodeName === 'img' && key === 'srcset' && value) {
-          if (!isString(value)) {
-            throw $compileMinErr('srcset', 'Can\'t pass trusted values to `$set(\'srcset\', value)`: "{0}"', value.toString());
-          }
-
-          // Such values are a bit too complex to handle automatically inside $sce.
-          // Instead, we sanitize each of the URIs individually, which works, even dynamically.
-
-          // It's not possible to work around this using `$sce.trustAsMediaUrl`.
-          // If you want to programmatically set explicitly trusted unsafe URLs, you should use
-          // `$sce.trustAsHtml` on the whole `img` tag and inject it into the DOM using the
-          // `ng-bind-html` directive.
-
-          var result = '';
-
-          // first check if there are spaces because it's not the same pattern
-          var trimmedSrcset = trim(value);
-          //                (   999x   ,|   999w   ,|   ,|,   )
-          var srcPattern = /(\s+\d+x\s*,|\s+\d+w\s*,|\s+,|,\s+)/;
-          var pattern = /\s/.test(trimmedSrcset) ? srcPattern : /(,)/;
-
-          // split srcset into tuple of uri and descriptor except for the last item
-          var rawUris = trimmedSrcset.split(pattern);
-
-          // for each tuples
-          var nbrUrisWith2parts = Math.floor(rawUris.length / 2);
-          for (var i = 0; i < nbrUrisWith2parts; i++) {
-            var innerIdx = i * 2;
-            // sanitize the uri
-            result += $sce.getTrustedMediaUrl(trim(rawUris[innerIdx]));
-            // add the descriptor
-            result += ' ' + trim(rawUris[innerIdx + 1]);
-          }
-
-          // split the last item into uri and descriptor
-          var lastTuple = trim(rawUris[i * 2]).split(/\s/);
-
-          // sanitize the last uri
-          result += $sce.getTrustedMediaUrl(trim(lastTuple[0]));
-
-          // and add the last descriptor if any
-          if (lastTuple.length === 2) {
-            result += (' ' + trim(lastTuple[1]));
-          }
-          this[key] = value = result;
+        if (nodeName === 'img' && key === 'srcset') {
+          this[key] = value = sanitizeSrcset(value, '$set(\'srcset\', value)');
         }
 
         if (writeAttr !== false) {