Meta.hx

/*
 * Copyright (C)2005-2019 Haxe Foundation
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included in
 * all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

package haxe.rtti;

private typedef MetaObject = {
	?fields:Dynamic<Dynamic<Null<Array<Dynamic>>>>,
	?statics:Dynamic<Dynamic<Null<Array<Dynamic>>>>,
	?obj:Dynamic<Null<Array<Dynamic>>>
};

/**
	An API to access classes and enums metadata at runtime.

	@see <https://haxe.org/manual/cr-rtti.html>
**/
class Meta {
	/**
		Returns the metadata that were declared for the given type (class or enum)
	**/
	public static function getType(t:Dynamic):Dynamic<Array<Dynamic>> {
		var meta = getMeta(t);
		return (meta == null || meta.obj == null) ? {} : meta.obj;
	}

	// Could move this to Type.hx?
	private static function isInterface(t:Dynamic):Bool {
		#if java
		return java.Lib.toNativeType(t).isInterface();
		#elseif cs
		return cs.Lib.toNativeType(t).IsInterface;
		#else
		throw "Something went wrong";
		#end
	}

	private static function getMeta(t:Dynamic):MetaObject {
		#if php
		return php.Boot.getMeta(t.phpClassName);
		#elseif (java || cs)
		var ret = Reflect.field(t, "__meta__");
		if (ret == null && Std.isOfType(t, Class)) {
			if (isInterface(t)) {
				var name = Type.getClassName(t),
					cls = Type.resolveClass(name + '_HxMeta');
				if (cls != null)
					return Reflect.field(cls, "__meta__");
			}
		}
		return ret;
		#elseif hl
		var t:hl.BaseType = t;
		return t.__meta__;
		#else
		return untyped t.__meta__;
		#end
	}

	/**
		Returns the metadata that were declared for the given class static fields
	**/
	public static function getStatics(t:Dynamic):Dynamic<Dynamic<Array<Dynamic>>> {
		var meta = getMeta(t);
		return (meta == null || meta.statics == null) ? {} : meta.statics;
	}

	/**
		Returns the metadata that were declared for the given class fields or enum constructors
	**/
	public static function getFields(t:Dynamic):Dynamic<Dynamic<Array<Dynamic>>> {
		var meta = getMeta(t);
		return (meta == null || meta.fields == null) ? {} : meta.fields;
	}
}