'this' reference from static method should be possible

[agu-z]

In JavaScript I am able to reference this from object methods, in order to access properties from the same object that stores my method, for example the prototype of the object.

Suppose I'm writing an ORM and I have a class Model and I want to implement an static method where that does a query in the DB for the corresponding table to that Model. I would write it like this:

class Model {
  public static where(options: any) {
     doWhereQuery(Reflect.getMetadata('table', this.prototype));
  }
}

 // Suppose that I have a decorator that sets the 'table' key in this class metadata
@table('users')
class User extends Model { }

User.where({ name: 'John', surname: 'Doe' });

But when I do so I get: error TS2334: 'this' cannot be referenced in a static property initializer.

I understand that maybe this is not the correct keyword to reference the "class", but that is the way it works in JavaScript and I think that this should be possible Otherwise, there is no trivial way to implement that functionality.

[RyanCavanaugh]

It is legal to reference this from a static method. The sample you posted does not produce the error given. Can you clarify?

[agu-z]

Oh sorry, you are right. But it produces that error if you do it from an static arrow function and I guessed it would happen from a static method too. Anyway, that is incorrect, isn't it?

class Model {
  public static where = (options: any) => doWhereQuery(Reflect.getMetadata('table', this.prototype));
}

'this' cannot be referenced in a static property initializer.at line 2 col 85

[RyanCavanaugh]

What's the intent with writing it as an arrow function and referencing this ?

If you want this to always refer to Model, then just write Model instead of this.

If you want this to refer to the class that it's invoked on but not require a method-style invocation (i.e. allow an unbound invocation var x = MyModel.where; x();), that's impossible because derived classes don't get a newly-closed-over own property for where, so there's no way for them to capture this. Trying to write out what the emit would look like in this case is an informative exercise.

[agu-z]

I forgot that arrow functions doesn't have own this, so this issue should be closed. Sorry for my ignorance.