AIR 3.0 and later


typedef FREObject (*FREFunction)( 
        FREContext             ctx, 
        void*            functionData, 
        uint32_t             argc, 
        FREObject             argv[] 


The FREContext variable that represents this extension context. See FREContext.

A void*. This pointer points to the data you associated with this FREFunction function in its FRENamedFunction structure. Your implementation of FREContextInitializer() passed a set of FRENamedFunction structures to the runtime in an out parameter. When the runtime calls the FREFunction function, it passes the function this data pointer. See FRENamedFunction.

The number of elements in the argv parameter.

An array of FREObject variables. These pointers correspond to the parameters passed after the function name in the ActionScript call to the ExtensionContext instance’s call() method.


An FREObject variable. The default return value is an FREObject for which the type is FRE_INVALID_OBJECT.


Implement a function with the FREFunction signature for each native function in the extension. The function name corresponds to the function field of an FRENamedFunction element in the array returned in the functionsToSet parameter of the FREContextInitializer() function.

The runtime calls this FREFunction function when the ActionScript side calls the ExtensionContext instance’s call() method. The first parameter of call() is the same as the name field of the FRENamedFunction element. Subsequent parameters to call() correspond to the FREObject variables in the argv array.

You define the FREFunction to return an FREObject variable. The type of the FREObject variable corresponds to the ActionScript type returned by the call() method. If the FREFunction has no return value, the default return value is an FREObject variable with the type FRE_INVALID_OBJECT. The default return value results in call() returning null on the ActionScript side.

Use the ctx parameter to:

  • Get and set data you associate with the extension. This data can be native context data and ActionScript context data. See Context-specfic data.

  • Dispatch an asynchronous event to the ExtensionContext instance on the ActionScript side. See FREDispatchStatusEventAsync().

Use the functions in Functions you use to work with the FREObject parameters and the return value, if any.