Fix missing callback
Fix missing callback

The callback function was never called whenever the widget skipped loading in the _loadData function. Mendix R&D found this issue in one of our tickets. The result of the missing callback resulted in non-responsive pages after a commit and refresh in a nanoflow.

Below is the full scenario (copied from Mendix ticket):

- When user clicks button, nanoflow NB_MobileWorkOrder_Step1_StartJourney is called.
- Change action inside this nanoflow triggers other widgets on the page update according to the new change
- As a part of this update, listView1 in SN_PhoneLayout_CurrentWorkorder reloads.
- Nanoflow waits for listView1 to finish reloading.
- listView1 loads the data and renders the first row which contains javaScriptSnippet_DataSource_1 custom widget.
- But this custom widget does not notify list view that it is loaded.
- Nanoflow does not continue.
mrgroen/JavaScript-Snippet