Replace default message 'load failed' in


I need to change the value (and probably translated) of which is by default set to load failed.
This string is been used inside the childDataSourceLoadFailed function.

I tried to redefine this method to change the value been displayed with the following way:

(function() {
  var request =;
  _.extend(request, {
    childDataSourceLoadFailed: function(sourceMapping, targetMappings, callback, signature) {
      var response = signature.response,
          data     = response.get('data'),
          loadfailedText = 'couscous';//this.get('loadfailedText');

      _.each(targetMappings, function(targetMapping) {
        _.each(data, function(dataItem) {
            dataItem[] = loadfailedText;


This does not work, I still got load failed! How I can set this value?


We should extend the prototype of Request.

var request =;


Thanks @Zicheng, this did the job for me:

var request =;
request.set('loadfailedText', 'my_new_value');