On Drop Database Method

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4D v17.4

The On Drop Database Method is available in local or remote 4D applications.

This database method is automatically executed in the case of objects being dropped in the 4D application outside of any form or windows context. Different drop actions are supported, depending on the platform and the application type:

Action	Platform(s)	Comment
Drop in an empty area of the MDI window	Windows	Not available when the database is executed in SDI mode since there is no MDI window in this context (see SDI mode on Windows section).
Drop on the 4D icon in the Dock	macOS
Drop on the 4D icon in the system desktop	Windows(*) & macOS	The On Drop Database Method is only called when the application is already launched, except in the case of applications merged with 4D Desktop. In this case, the database method is called even when the application is not launched. This means that it is possible to define custom document signatures.

(*) Not supported with 4D Developer 64-bit on Windows because this action launches a new application instance (system feature).

On Mac, you need to hold down the Option+Command keys during the drop in order for the database method to be called.

Example

This example can be used to open a 4D Write document that is dropped outside of any form:

  `On Drop database method

 droppedFile:=Get file from pasteboard(1)

 If(Position(".4W7";droppedFile)=Length(droppedFile)-3)

    externalArea:=Open external window(100;100;500;500;0;droppedFile;"_4D Write")

    WR OPEN DOCUMENT(externalArea;droppedFile)

 End if