Question

I have the following function that takes this frequency parameter and calls the api, but the parameter frequency is not defined inside the SUCCESS callback and I need it. How to pass that parameter to my callback?

 init : function(frequency) {
    $.ajax({
        url: 'api/v1/dashboard',
        type: "GET",
        dataType: "json",
        data : {username : "demo",frequency : frequency},
        success: function(data) {
            dashboard_hander.set_data(data.dashboard);
                            //here frequency is undefined

        }
    });
},

EDIT 2 =====

It works by defining parameters = {username : “demo”,frequency : frequency};
outside of the $.ajax and passing as data object, or defining frequency in a higher scope, like:

 var dashboard_hander = {
frequency : "",
init : function(frequency) {
    this.frequency = frequency;

       ...
    }
 } 

Answer 1

Just define it at a higher scope.

   init : function(frequency) {
        var myData = {username : "demo",frequency : frequency};
        $.ajax({
            url: 'api/v1/dashboard',
            type: "GET",
            dataType: "json",
            data : myData,
            success: function(data) {
                alert(myData.frequency);
                dashboard_hander.set_data(data.dashboard);
                                //here frequency is undefined

            }
        });
    },