Zuu's Reflection API


804.0.24 years ago4 years agoMinified + gzip package size for @zuu/mirror in KB



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What is Mirror?

Mirror is a very powerfull reflection api created for typescript, mainly used with the zuu framework (for dependency injection, assertion and other cool stuff).

Want to contribute?

Here's how!


The basic principle is easy. Decorations are attached to classes, properties, methods and method parameters and can be reflected after by a very powerfull reflection engine (that also provides aditional information about the types, names, positions, etc).

The first step is to create a new decoration:

// just extend the IDecoration interface
interface GParameters extends IDecoration {
    x: number;
    y?: string;

After that we can define our decorator logic:

// just extend the AbstractDecorator<T> and provide a IDecoration type
class GDecorator extends AbstractDecorator<GParameters> {
    constructor() {
        // provide information about the MirrorType [CLASS, PROPERTY, METHOD, PARAMETER] and a namespace (must be unique)
        super(MirrorType.CLASS, "demos.class.g");

    public annotate(instance: GParameters, target: any, key?: string | symbol, index?: number) {
        // here you can process your decoration placement

Now we can ask mirror to build our decorator: (don't forget to say please)

// Hey Mirror, sorry for bothering you, but can you please make a new decorator?
//  It will be a ClassDecorator and will bind to GParameters decoration :) Thanks
let G = Mirror.decorator<GParameters, ClassDecorator>(new GDecorator);

That's all :) Now you can use it on any class like so:

@G({x: 3, y: "abcd"})
class Dummy { };

It's a decorator factory actually... but you can convert it to a decorator just by calling it with the decoration:

let g = G({x: 0});

class Dummy2 {};

You can now reflect on your class or class instances (also on specific methods and properties):

let reflection: ReflectedClass = Mirror.reflect<ReflectedClass>(Dummy);

let instance = new Dummy2()
let instanceReflection: ReflectedClass = Mirror.reflectInstance<ReflectedClass>(instance);


Object Reflection Decorator
type ReflectedType -
class ReflectedClass ClassDecorator
property ReflectedProperty PropertyDecorator
method ReflectedMethod MethodDecorator
parameter ReflectedParameter ParamterDecorator

If you find any bugs or have a feature request, please open an issue on github!

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