this.<servicename> not available inside error function in angular2

Question

I have a strange error in angular2. while the following code works fine

loginResult.subscribe(
      (data) =>
        this.response = data,
      (err) =>

        this._ajaxService.handleError(err, 'A string to summarize the activity')
    );

The following code says cannot read property handleError of undefined. This happens only in case of a failed request.

    loginResult.subscribe(
   function (response) {

        this.response = response;
        console.log(this.response);

      },
      function (error) {

        this._ajaxService.handleError(error, 'A string to summarize the activity')

      }
    );

Answer 1

Bind "this" to both success and failure functions.

loginResult.subscribe(
    function (response) {
        this.response = response;
        console.log(this.response);
    }.bind(this), // <== "this" binding here
    function (error) {
        this._ajaxService.handleError(error, 'A string to summarize the activity')
    }.bind(this)
);