Haxe macro - Open file with relative path

Question

I'm writing a macro that needs to open a directory which is in the same folder as my macro class. The problem is that I need to be able to do the same thing, without the need to be aware about macro's folder.

My question is simple, is there a way to open the FileSystem in macro, in the current directory.

e.g : a (b (Macro.hx, c (...) ) )

I need to open "c" directly when I'm running macro methods from "Macro.hx"

If you have an idea, Thank you :)

Answer 1

You can use a function like this inside of a macro:

    static function loadFileAsString(path:String) {
        try {
            var p = haxe.macro.Context.resolvePath(path);
            return sys.io.File.getContent(p);
        }
        catch(e:Dynamic) {
            return haxe.macro.Context.error('Failed to load file $path: $e', Context.currentPos());
        }
    }

Basically, Context.resolvePath will resolve a path relative to all of your class paths. So if your macro is in a file my/package/MyMacro.hx, and you want to load my/package/MyMacroData.json, you could use:

haxe.macro.Context.resolvePath( 'my/package/MyMacroData.json' );

This will check every classpath in your build - including any haxelibs etc, so it will find your file, but it will be possible to "shadow" it, by having a file in the same package/location but in a different class path or haxelib, so try to use a unique package/name so this doesn't happen by accident.

But it should work fine for you, I use it in my compiletime library if you want to look at an example implementation. I've linked to the function with the relevant code.