Function mergeTemplateAttributes

test/angular/1.7/angular.js:10807–10839

* When the element is replaced with HTML template then the new attributes * on the template need to be merged with the existing attributes in the DOM. * The desired effect is to have both of the attributes present. * * @param {object} dst destination attributes (original DOM)

(dst, src)

     * @param {object} src source attributes (from the directive template)
     */
    function mergeTemplateAttributes(dst, src) {
      var srcAttr = src.$attr,
          dstAttr = dst.$attr;

      // reapply the old attributes to the new element
      forEach(dst, function(value, key) {
        if (key.charAt(0) !== '$') {
          if (src[key] && src[key] !== value) {
            if (value.length) {
              value += (key === 'style' ? ';' : ' ') + src[key];
            } else {
              value = src[key];
            }
          }
          dst.$set(key, value, true, srcAttr[key]);
        }
      });

      // copy the new attributes on the old attrs object
      forEach(src, function(value, key) {
        // Check if we already set this attribute in the loop above.
        // `dst` will never contain hasOwnProperty as DOM parser won't let it.
        // You will get an "InvalidCharacterError: DOM Exception 5" error if you
        // have an attribute like "has-own-property" or "data-has-own-property", etc.
        if (!dst.hasOwnProperty(key) && key.charAt(0) !== '$') {
          dst[key] = value;

          if (key !== 'class' && key !== 'style') {
            dstAttr[key] = srcAttr[key];
          }
        }
      });
    }


    function compileTemplateUrl(directives, $compileNode, tAttrs,