This is the legacy 4D documentation web site. Documentations are progressively being moved to developer.4d.com
- 4D Language Reference
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- Database Methods
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Database Methods
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On Backup Shutdown database method
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On Backup Startup database method
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On Drop database method
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On Exit database method
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On Host Database Event database method
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On Mobile App Action database method
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On Mobile App Authentication database method
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On Server Close Connection database method
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On Server Open Connection database method
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On Server Shutdown database method
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On Server Startup database method
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On SQL Authentication database method
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On Startup database method
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On System Event database method
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On Web Authentication database method
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On Web Connection database method
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On Web Legacy Close Session database method
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On REST Authentication database method
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On Drop database method
| On Drop database method | ||||||||
| Does not require any parameters | ||||||||
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.
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
Product: 4D
Theme: Database Methods
Modified: 4D v16 R4
4D Language Reference ( 4D v20 R7)
