Jsbool js_definefunction(), Unsigned short *js_valuetostring() – Adobe Extending Flash Professional CS5 User Manual

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EXTENDING FLASH PROFESSIONAL

C-Level Extensibility

Last updated 5/2/2011

typedef JSBool (*JSNative)(JSContext *cx, JSObject *obj, unsigned int argc,
jsval *argv, jsval *rval)

Description
Method; describes C-level implementations of JavaScript functions in the following situations:

•

The cx pointer is a pointer to an opaque

JSContext

structure, which must be passed to some of the functions in

the JavaScript API. This variable holds the interpreter’s execution context.

•

The obj pointer is a pointer to the object in whose context the script executes. While the script is running, the

this

keyword is equal to this object.

•

The argc integer is the number of arguments being passed to the function.

•

The argv pointer is a pointer to an array of

jsval

structures. The array is

argc

elements in length.

•

The rval pointer is a pointer to a single

jsval

structure. The function’s return value should be written to

*rval

.

The function returns

JS_TRUE

if successful;

JS_FALSE

otherwise. If the function returns

JS_FALSE

, the current script

stops executing and an error message appears.

JSBool JS_DefineFunction()

Usage

JSBool JS_DefineFunction(unsigned short *name, JSNative call, unsigned int nargs)

Description
Method; registers a C-level function with the JavaScript interpreter in Flash. After the

JS_DefineFunction()

function registers the C-level function that you specify in the call argument, you can invoke it in a JavaScript script by
referring to it with the name that you specify in the name argument. The name argument is case-sensitive.

Typically, this function is called from the

MM_Init()

function, which Flash calls during startup.

Arguments

unsigned short *

name,

JSNative

call,

unsigned int

nargs

•

The name argument is the name of the function as it is exposed to JavaScript.

•

The call argument is a pointer to a C-level function. The function must return a

JSBool

, which indicates success or

failure.

•

The nargs argument is the number of arguments that the function expects to receive.

Returns
A Boolean value:

JS_TRUE

indicates success;

JS_FALSE

indicates failure.

unsigned short *JS_ValueToString()

Usage

unsigned short *JS_ValueToString(JSContext *cx, jsval v, unsigned int *pLength)

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