To upload or download a file using the File Manager, the File Manager widget needs to work with a file. In Mendix this done using a specialisation of the System.FileDocument entity.
So, if you wanted to upload a PDF of a document, you would create an entity in your domain model for your module. You then make this entity a generalisation of System.FileDocument. On your page, you use this entity as a parameter for a DataView, and place the File Manager widget inside this DataView. Now, when you interact with the File Manager, it will use this new entity for the uploading / downloading of a file.
Hope this helps
I am trying to do the same approach, I could not be able to tap the attach button as it was in deselected state by default. How to solve this one ?
You need to do something like this:
then create a new page where the invoice is created, and you can add that widget there:
If you place it outside the page parameter you will get that error because Mendix does not understand where it should store the file:
Make sure that the right roles can create this object and it should look like this: