Adobe AIR Development

[anandr37]

Hello All,

I have a simple application which adds 2 number using ANE native methods.

I am getting the exception:

TypeError: Error #1009: Cannot access a property or method of a null object reference.
at com.math::MathLibrary/sayHello()[C:\FlashBuilder_ws\MathLibrary\src\com\math\MathLibrary.as:16]
at UsingMath2/onHelloButtonClick()[C:\FlashBuilder_ws\UsingMath2\src\UsingMath2.as:62]

Below is the code for the same

Native Side:

#include "FlashRuntimeExtensions.h"
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

void ExtensionInitializer(void** extDataToSet,
		FREContextInitializer* ctxInitializerToSet,
		FREContextFinalizer* ctxFinalizerToSet);
void ExtensionFinalizer();

void ContextInitializer(void* extData, const uint8_t* ctxType, FREContext ctx,
		uint32_t* numFunctionsToSet, const FRENamedFunction** functionsToSet);
void ContextFinalizer(FREContext ctx);

FREObject sayHello(FREContext ctx, void* functionData, uint32_t argc,
		FREObject argv[]);

FREObject addValues(FREContext ctx, void* functionData, uint32_t argc,
		FREObject argv[]);


FREObject sayHello(FREContext ctx, void* functionData, uint32_t argc,
		FREObject argv[]) {
	const char *out = "Hello from the native code!";
	FREObject result;
	FRENewObjectFromUTF8((uint32_t)(strlen(out) + 1), (uint8_t*) out, &result);
	return result;
}

FREObject addValues(FREContext ctx, void* functionData, uint32_t argc,
		FREObject argv[]) {
		int32_t valueOne = 0;
		int32_t valueTwo = 0;
		FREGetObjectAsInt32( argv[ 0 ], &valueOne );
		FREGetObjectAsInt32( argv[ 1 ], &valueTwo );

		int32_t resultValue = valueOne + valueTwo;

		const char *out = (char)resultValue;

		FREObject result;
		FRENewObjectFromUTF8((uint32_t)(strlen(out) + 1), (uint8_t*) out, &result);
		return result;
}


void ExtensionInitializer(void** extDataToSet,
		FREContextInitializer* ctxInitializerToSet,
		FREContextFinalizer* ctxFinalizerToSet) {
	*extDataToSet = NULL;
	*ctxInitializerToSet = &ContextInitializer;
	*ctxFinalizerToSet = &ContextFinalizer;
}

/**
 * The runtime calls this function when it disposes of the ExtensionContext instance
 * for this extension context.
 */
void ExtensionFinalizer() {
}


void ContextInitializer(void* extData, const uint8_t* ctxType, FREContext ctx,
		uint32_t* numFunctionsToSet, const FRENamedFunction** functionsToSet) {
	char *temp = NULL;
	int i;

	// define an array of functions
	const char *functionNames[] = { "sayHello","addValues", NULL };
	FREFunction functionPtrs[] = { sayHello,addValues, NULL };

	// count number of functions
	*numFunctionsToSet = 0;
	while (functionPtrs[*numFunctionsToSet] != NULL) {
		(*numFunctionsToSet)++;
	}

	FRENamedFunction *functionSet = calloc(*numFunctionsToSet,
			sizeof(FRENamedFunction));

	for (i = 0; i < *numFunctionsToSet; i++) {
		int bufferSize = sizeof(char) * (strlen(functionNames[i]) + 1);
		temp = (char*) malloc(bufferSize);
		strncpy(temp, functionNames[i], bufferSize);
		temp[strlen(functionNames[i])] = '\0';
		functionSet[i].name = (uint8_t*) temp;
		functionSet[i].functionData = NULL;
		functionSet[i].function = functionPtrs[i];
	}

	*functionsToSet = functionSet;
}


void ContextFinalizer(FREContext ctx) {
}

 ANE Library:

package com.math
{
	import flash.external.ExtensionContext;
	
	public class MathLibrary
	{
		private var _ctx:ExtensionContext;
		
		public function MathLibrary()
		{
			this._ctx = ExtensionContext.createExtensionContext( 
				"com.math.MathLibraryNative", null);
		}
		
		public function sayHello(v1:int, v2:int ): Object {
			var result:Object = this._ctx.call( "addValues",v1,v2 );
			return result;
		}
	}
}

Where the call is made:

private function onHelloButtonClick(event:MouseEvent):void
		{
			this.extension = new MathLibrary();
			var out:String = new String(this.extension.sayHello(2,4));
			helloLabel.text = out;
		}

 I have the entries <action system="true">run_air_native</action> in the bar-descriptor

and the entry 

<extensions>
<extensionID>com.example.MathLibraryNative</extensionID>
</extensions>

in the app.xml

Please let me know where I am going wrong here ?

Also kindly do let me know if there are any good sample apps/tutorials for Passing parameters to native

using ANE in playbook.

[Smugrik]

Is it com.math, or com.example? Make sure these ids match..

[anandr37]

Thanks a lot, that really worked. I had to just change the ANE library

code to "com.math.MathLibraryNative", null) and it worked !!!!

However still not able to figure out what decides the package name

for the air extension. Any suggestions here ?