将带有 arguments 的成功回调 function 传递给另一个执行 ZA34A6659BCEAE779F28185E757 调用的 function

Question

I'm new to javascript and trying to understand if following thing is possible:

Let's say I use following ajax request construction in several places in my code (with different success callback functions - in this example only handleSuccessCallback() ) and different url and data request param:

  jQuery.ajax({
        type: 'GET',
        url: loadUrl,
        data: data,
        error: errorCallback,
        success: function(response) {
            this.handleSuccessCallback(response);
        }
    }); 

function handleSuccessCallback(response) {
     Do something with response here...
}

I wanted to refactor this code in such way, that I don't need to create construction above each time I need to send request. I wanted to create a function in my utils class that will take url, request data and error/success callback. Something like this:

 function sendAjaxRequest(url, data, errorCallback, successCallback)
  jQuery.ajax({
        type: 'GET',
        url: url,
        data: data,
        error: errorCallback,
        success: successCallback
  }); 
 }

Then, I wanted to call this function several times passing different arguments from my main script.

In my main code:

var url = "https://some url";
var data = {};
var errorCallback = handleErrorCallback();
var successCallback = handleSuccessCallback(); // ??? This function requires `response` argument being passed, how it can be done?

utils.sendAjaxRequest(url, data, errorCallback, successCallback);


function handleSuccessCallback(response) {
     Do something with response here...
}

function handleErrorCallback() {
     Do something with error here...
}

However, what I don't understanding is the following: how can I pass success callback function ( handleSuccessCallback(response) ) to the sendAjaxRequest() function, if my handleSuccessCallback(response) needs params which is result of the success ajax callback itself( response )?

How can I pass this response param to handleSuccessCallback() when passing it to sendAjaxRequest() if I don't know yet what will be the response from ajax call?

Answer 1

When you want to call:

function sendAjaxRequest(url, data, errorCallback, successCallback)

You just need to give names of functions for errorCallback and successCallback . You are passing function references, so they can be called by other code. The params are provided at the point where those functions are called, like in your original example:

success: function(response) {
        this.handleSuccessCallback(response);
    }

Here the success function as defined in ajax with first parameter as response , so you have an anonymous function here with the first parameter as response .

So you just need to define your functions to match what they will be when they get called by ajax , eg:

var firstSuccessCallback = function(response) {
    //do something;
}

var firstErrorCallback = function(error) {
    //do something;
}

you can do:

sendAjaxRequest(url, data, firstErrorCallback, firstSuccessCallback)