TyZ - Thijs Broerse - Flash Developer

If you have a function reference in Flash there is not a lot of information you can get from it. Converting the function to a string will only give you:

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"function Function() {}"

A describeType() wouldn’t give you more information either. Specially for debug purposes you would like to have some more information about the function, like his name or class.

By coincident I discovered that Flash throws an error if you try to cast a function to something else. The error message contains some more information about the function:

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"TypeError: Error #1034: Type Coercion failed: cannot convert MC{FunctionUtilsExample@2ac32e1 FunctionUtilsExample/myPrivateFunction()}@2ccbb21 to flash.utils.Dictionary.
at FunctionUtilsExample()"

So a simple regular expression gave me the information I wanted. I created the following function in FunctionUtils for the Temple:

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public static function functionToString(func:Function):String
{
	try
	{
		Dictionary(func);
	}
	catch (error:Error)
	{
		var regExp:RegExp = /MC{(?:.*) (.*)}/g;
		var s:String = String(regExp.exec(String(error.message))[1]);
		var i:int = s.indexOf("/");
		var className:String = s.substr(0, i);
		var functionName:String = s.substr(i);
		functionName = functionName.substr(functionName.indexOf("::") + 2);
 
		if (Temple.displayFullPackageInToString || className.indexOf('::') == -1)
		{
			return className + "." + functionName;
		}
		else
		{
			return className.split('::')[1] + "." + functionName;
		}
	}
	return null;
}

Example:

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FunctionUtils.functionToString(new MovieClip().gotoAndPlay);

returns

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"MovieClip.gotoAndPlay()"

A lot more readable I think.

Unfortunately this only works in the Debug Player, but you should only use this for debug purposes.

Sources, including an example, is available from GoogleCode.

This entry was posted on Friday, April 23rd, 2010 at 17:03 and is filed under Open source, English, Tricks, Temple, Flash. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.