Pass Class as parameter

haxe

Solution

Class has a Type Parameter, so if you're going to accept a class as an argument, you need to specify a type parameter.

Accept any class:

function foo(myClassRef:Class<Dynamic>):Void {
    var myVar = Type.createInstance( myClassRef, [constructorArg1, constructorArg2....] );
    trace( Type.typeof(myVar) );
}

Accept only "sys.db.Object" class or sub classes:

function foo(myClassRef:Class<sys.db.Object>):Void {
    var myVar = Type.createInstance( myClassRef, [] );
    trace( Type.typeof(myVar) );
}

Haxe 3 also allows generic functions:

@:generic function foo<T:Dynamic>(t:Class<T>) {
    var myVar = new T();
    trace( Type.typeof(myVar) );
}

Here you declare the function to be generic, which means that for each different type parameter, a different version of the function will be compiled. You accept Class, where T is the type parameter - in this case, dynamic, so it will work with any class. Finally, using generic functions let's you write `new T()`, which may seem a more natural syntax, and there may be performance benefits on some platforms.

Problem

I'm trying to pass a Class reference and instantiate it in a function. This doesn't work: ``` function foo(myClassRef:Class):Void { var myVar = new myClassRef(); } foo(MyClass); ``` It gives `Unexpected (`. Is this possible in Haxe 3?

Original source