Get all classes from a package - haxe

Question

I'd like a (platform independent) way to list all classes from a package.
A possible way would be get a list of all classes known by Haxe, then filtering through it.

Answer 1

I made a macro to help with just this. It's in the compiletime haxelib.
haxelib install compiletime
And then add it to your build (hxml file):
-lib compiletime
And then use it to import your classes:
// All classes in this package, including sub packages.
var testcases = CompileTime.getAllClasses("my.package");
// All classes in this package, not including sub packages.
var testcases = CompileTime.getAllClasses("my.package",false);
// All classes that extend (or implement) TestCase
var testcases = CompileTime.getAllClasses(TestCase);
// All classes in a package that extend TestCase
var testcases = CompileTime.getAllClasses("my.package",TestCase);
And then you can iterate over them:
for ( testClass in testcases ) {
var test = Type.createInstance( testClass, [] );
}
Please note, if you never have "import some.package.SomeClass" in your code, that class will never be included, because of dead code elimination. So if you want to make sure it gets included, even if you never explicitly call it in your code, you can do something like this:
CompileTime.importPackage( "mygame.levels" );
CompileTime.getAllClasses( "mygame.levels", GameLevel );
How it works
CompileTime.getAllClasses is a macro, and what it does is:
Waits until compilation is finished, and we know all of the types / classes in our app.
Go through each one, and see if it is in the specified package
See also if it extends (or implements) the specified class/interface
If it does, add the class name to some special metadata - #classLists(...) metadata on the CompileTimeClassList file, containing the names of all the matching classes.
At runtime, use the metadata, together with Type.resolveClass(...) to create a list of all matching types.

Answer 2

This is one way to store and retrieve the information: https://gist.github.com/back2dos/c9410ed3ed476ecc1007
Beyond that you could use haxe -xml to get the type information you want, then transform it as needed (use the parser from haxe.rtti to handle the data) and embed the JSON encoded result with -resource theinfo.json (accessed through haxe.Resource).
As a side note: there are chances you'll be better off not having any automation and just add the classes to an array manually. Imagine you have somepackage.ClassA, somepackage.ClassB, ... then you can do
import somepackage.*;
//...
static var CLASSES:Array<Class<Dynamic>> = [ClassA, ClassB, ...];
It gives you more flexibility as whatever you want to do, you can always add 3rd party classes, which may not necessarily be in the same package and you can also choose to not use a class without having to delete it.