Creating custom plug-ins
If you are a C or C++ programmer and familiar with calculations in FileMaker Pro and FileMaker Pro Advanced, you can create plug-ins that extend the feature set of the FileMaker application. The plug-ins can take advantage of recursion and looping or hook into other programming interfaces.
To use plug-ins, FileMaker Pro users need to allow solution files to install plug-ins and enable plug-ins. For FileMaker Server-hosted files, the server administrator needs to allow the Install Plug-In File script step to update FileMaker Server plug-ins in the Server Admin Console.
Note  Plug-ins are not supported in FileMaker Go.
To see an example plug-in, go to //www.filemaker.com/downloads.
Follow these general steps to prepare your custom plug-ins:
1.
In Windows, the plug-in extension must be .fmx. In OS X, the plug-in extension must be .fmplugin.
2.
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To make plug-ins available in a file, instruct users to:
1.
2.
Click Configure and define or edit a calculation field to access external functions provided by the plug-in, if required.
3.
Note  To display all available external functions, select External functions from the View list.
4.
If you want plug-in updates to be installed automatically, ensure Allow Solutions to Install Files is selected.
See Installing plug-ins.
Note  For security reasons, system administrators might require users to disable Allow Solutions to Install Files. Contact the system administrator at your customer site for more information.
Related topics 
External functions