JavaScript bind method does not work on getter property

Question

Trying to do this:

var c = {
  x: \'other context\'
};

var o = {
  x: \'this context\',
  get otherContext () {
    alert(this.x);
  }.bind(c)
};

o.otherCon         


        

Answer 1

The problem is that method syntax doesn't use function expressions. It's a defined syntactic structure.

MethodDefinition[Yield] :

PropertyName[?Yield] ( StrictFormalParameters ) { FunctionBody }

GeneratorMethod[?Yield]

get PropertyName[?Yield] ( ) { FunctionBody }

set PropertyName[?Yield] ( PropertySetParameterList ) { FunctionBody }

PropertySetParameterList :

FormalParameter

Since it isn't a function expression, you don't have access to the functions methods or properties.

You can accomplish what you want with Object.defineProperty.

var proxy = { ... };
Object.defineProperty(proxy, 'left', {
  get: function() {
    return this.el.offsetLeft;
  }.bind(this)
});