es6 Javascript class using this inside a callback [duplicate]

Answer 1

Put a reference to dir in aMethod(), then use that in aFunc like

aMethod() {
    var tempDir = this.dir;
    aFunc() {
        console.log(tempDir);
    }
}

Answer 2

You have the following options:

1) Use an arrow function:

class ClassName {
  // ...
  aMethod(){
    let aFun = () => {
      this.dir;// ACCESS to class reference of this
    }
  }
}

2) Or the bind() method:

class ClassName {
  // ...
  aMethod(){
    var aFun = function() {
      this.dir;// ACCESS to class reference of this
    }.bind(this);
  }
}

3) Store this in a specialised variable:

class ClassName {
  // ...
  aMethod(){
    var self = this;
    function aFun() {
      self.dir;// ACCESS to class reference of this
    }
  }
}

This article describes the necessary details about this and arrow functions in JavaScript.