I have an application where a user needs to drag and drop attachments from their hard drive into the application; the application stores documents relating to building projects like floor plans, location plans, pictures of gardens etc.
Use cases:
I want to select a bunch of files of a certain type and drag them into the application. I need to tell the system what they are, so I will need to specify that they are all 'floor plans' for example.
I want to select a bunch of files of mixed type and drag them into the application. I need to tell the system what each one is because they will be different, e.g. one is a floor plan, the other is a picture of a house, etc.
I'm thinking that there needs to be a control that sets global metadata for the dragged set of documents and an individual control that allows the user to override global metadata with individual document metadata.
Does anyone have a good pattern for this complex scenario?


