Try...catch for getQualifiedClassName

1

How do I check if a class exists? and handle the error if it doesn’t?

if the class exists the code below traces
// no Error
// Finally!

However if it doesnt exist i get a compiler error
// 1120: Access of undefined property cm_button_bg_g

I was leaad to believe the try catch statement should handle the compiler error… Am I going about this the wrong way?


try {
   getQualifiedClassName(cm_button_bg_g) == "cm_button_bg_g";
   trace("no Error ");
} catch(error:Error) {
   trace("Error catch: " + error);
} finally {
   trace("Finally!");
}

Any help would be greatly appreciated :slight_smile:

2

getQualifiedClassName() doesn’t throw any errors. The error you’re getting isn’t a run-time error, it’s compile-time… Sure, if there’s no cm_button_bg_g variable it won’t compile…
Did you mean getDefinitionByName()? it may throw ReferenceError.

3

getQualifiedClassName will return the classname of the object you pass to it. In this case you want to check if a class is actually existing right?

Try this on for size;


var classExists:Boolean = true;
var classNameToTest:String = "flash.display.Sprite";

try 
{
   var k = getDefinitionByName(classNameToTest);
} 
catch(e:Error) 
{
   trace("Statement threw an error: " + e);
   classExists = false;
} 

classExists ? trace("Your class exists") : trace("Your class doesn't exist");
4

Oh man, words can not describe how helpful those posts are! works a treat now.

I also know to look for the throws heading in help when using try catch now.

thanks again :slight_smile:

5

You’re welcome :smiley: