We need to define two different layers inside a wrapper. One is a "fake" zone that is always visible and could be whatever you want (with more elements inside), and the other is the "real" drop zone, that is only visible when we are dragging a file.
Note: The aim of this plugin is just to detect the drag event over the element where we listen a drop event, and detect also the drag outside this element. But management and behaviour after the drop event (e.g.upload the file) ∫is out of the scope of this plugin. It could be done with other libraries like for example Simple Ajax Upload.
Drag and drop here your file.