What does Google Picker API drivepreopen do?

Question

I've noticed that some google drive apps fire POST request to https://docs.google.com/picker/drivepreopen?hostId=myhost upon file selection in picker dialog. Does anybody know what it does? I need to be able to access my google docs files from my google drive app and I'm aware of the fact that drive apps can access only files it created or opened via context menu in google drive. As the name "drivepreopen" suggests maybe it allows you to programmatically invoke "open with"?

Answer 1

The Picker is how your app should be given access to a file and it can be used to display a list of the currently authenticated user's Drive files, as explained at https://developers.google.com/drive/integrate-open#open_files_using_the_google_picker.