How to call external method from nested ajax (success) method?

Question

I need to call onSuccessLogin method from ajax success method, or put response as argument into onSuccessLogin. Thank you for answers.

submit: function (form) {

      $.ajax({
        type: "post",
        url: "/login",
        data: {
          login: $(form).find('#login').val(),
          password: $(form).find('#password').val(),
          deviceType: environmentInfo.browser,
          sdkVersion: environmentInfo.browserVersion,
          osVersion: environmentInfo.OS
        },

        success: function(res) {
          localStorage.setItem("languagesList", res);
          //how to call onSuccessLogin method from here?
        },

    	//Another implementation
        // success: this.onSuccessLogin(res), - dosen't work, if I want put response from ajax into this method call

        error: this.onErrorLogin
      });
    },

onSuccessLogin: function () {
  //localStorage.setItem("languagesList", res); get response from second implementation
  window.location = "/";
}

Answer 1

By creating a reference (that can be seen from the scope of AJAX success callback) to the object holding onSuccessLogin.

Inside the submit method (as a sibling of onSuccessLogin) that object is this.

Also see MDN reference on ES6 Arrow functions - abstraction for binding this to enclosing scope.

submit: function (form) {

      var self = this;
  
      $.ajax({
        type: "post",
        url: "/login",
        data: {
          login: $(form).find('#login').val(),
          password: $(form).find('#password').val(),
          deviceType: environmentInfo.browser,
          sdkVersion: environmentInfo.browserVersion,
          osVersion: environmentInfo.OS
        },

        success: function(res) {
          localStorage.setItem("languagesList", res);
          self.onSuccessLogin();
        },

    	//Another implementation
        // success: this.onSuccessLogin(res), - dosen't work, if I want put response from ajax into this method call

        error: this.onErrorLogin
      });
    },

onSuccessLogin: function () {
  //localStorage.setItem("languagesList", res); get response from second implementation
  window.location = "/";
}