check isUrl

 var urlRegEx = /(http|https|ftp):\/\/[-a-zA-Z0-9@:%_\+.~#?&\/\/=]{2,256}\.[a-z]{2,4}\b(\/[-a-zA-Z0-9@:%_\+.~#?$&\/\/=]*)?/gi;

    //If entered data doesn't match the URL regex, then return error data, and don't actually make the AJAX request.
    if (!urlRegEx.test(link)) {
      var badURL = {warning: "Snap! That link came back with nothing. How about pasting it in?", tags: []};
      $scope.suggestedData = badURL;
      return;
    }