update rewriteStaticLinks utility function(modifiy only relative urls)

STUD-674

common/static/js/spec/utility_spec.js

@@ -10,4 +10,9 @@ describe('utility.rewriteStaticLinks', function () {
     it('returns "content" if "from" is not found', function () {
         expect(rewriteStaticLinks('<img src="/static/foo.x"/>', '/statix/', 'howdy')).toBe('<img src="/static/foo.x"/>')
     });
+    it('does not replace of "from" to "to" if "from" is part of absolute url', function () {
+        expect(
+            rewriteStaticLinks('<img src="http://www.mysite.org/static/foo.x"/>', '/static/', 'howdy')
+        ).toBe('<img src="http://www.mysite.org/static/foo.x"/>')
+    });
 });

common/static/js/src/utility.js

@@ -24,7 +24,18 @@ window.rewriteStaticLinks = function(content, from, to) {
     if (from === null || to === null) {
         return content;
     }
-
-    var regex = new RegExp(from, 'g');
-    return content.replace(regex, to);
-};
+    // replace only relative urls
+    function replacer(match){
+        if (match === from){
+            return to;
+        }
+        else {
+            return match;
+        }
+    }
+    // change all relative urls only which may be embedded inside other tags in content.
+    // handle http and https
+    // note: add other protocols here
+    var regex = new RegExp("(https?:\/\/(www\.)?[-a-zA-Z0-9@:%._\+~#=]{2,256}\.[a-z]{2,6}([-a-zA-Z0-9@:%_\+.~#?&//=]*))?"+from, 'g');
+    return content.replace(regex, replacer);
+};