Hi Karunakaran,
I created the File Dropper widget, can you please explain what the issue is? Your domain setup seems fine to me. Using that domain model you should be able to automatically set the association.
In your setup, you set the following:
That's all. When you upload pictures, they should automatically be associated with the PracticeTest object
If you create an overview page of all your practices, you could create for example a ListView for the PracticeTest objects, then use a dataview that listens to this listview, which will show a listview of all images, that you got over an association.
Hope this makes sense to you?
Have you tried the dropzone widget?
Hope this helps