AJAX is not a programming language. So what is it?

Question

I’m asking this question because I’m tired of seeing things as requirements for a certain programming position:

You need to know the languages PHP, Javascript, CSS and AJAX

I have learned that AJAX is not a programming language (of course, because no one "program in AJAX").

But when it comes to the question of terms, how should we classify AJAX? Resource? Technology? How should it be termed?

Answer 1

The AJAX is a "way" of using the Xmlhttprequest, which is not a language, but a API of Javascript, as well as File API, DOM API, etc..

What the XHR (Xmlhttprequest API) does is a client and server communication, does not mean that it is asynchronous, whereas AJAX is the way to use XHR "asynchronously".

Example of synchronous XHR (this is not AJAX):

var oReq = new XMLHttpRequest();

//Defina como false
oReq.open("GET", "/url", false);

//Espera completar a requisição, geralmente congela o browser
oReq.send(null);

alert(oReq.responseText);

Example of asynchronous XHR (this is AJAX):

var oReq = new XMLHttpRequest();

//Defina como true
oReq.open("GET", "/url", true);

//Função assíncrona que aguarda a resposta
oReq.onreadystatechange = function()
{
    if (oReq.readyState === 4) {
        alert(oReq.responseText);
    }
};

//Envia a requisição, mas a resposta fica sendo aguardada em Background
oReq.send(null);

So Ajax means Tosynchronous JavaScript tond XML (translating is asynchronous Javascript and XML) and is the way to use XHR that makes it AJAX or not. The term AJAX would be a nickname for the XHR used asynchronously.

It is important to note that the synchronous mode was "nicknamed" SJAX, which means Synchronous JavaScript tond XML (Javascript and synchronous XML)), but also note that SJAX is out of use and modern browsers have begun to emit warnings on the console and will probably come to "block" this way, however within Web Workers, as it runs on a separate "thread" as well as the error message states:

synchronous xmlhttprequest on the main thread is deprecated

In other words, only in main thread, which refers to the main thread running on the tab, the Web Works perform on sub-threads, which causes no problem and in this case is not in disuse.

More details on https://xhr.spec.whatwg.org/#Sync-Warning

Another situation is that we don’t always use XML, but at the time the nickname came up it was quite used to have support for .resposeXML XHR, to use JSON today we can do the parse of .responseText with something like:

var resposta = JSON.parse(oReq.responseText);

console.log(resposta);

Or you can adjust the property XMLHttpRequest.responseType to "json" and use XMLHttpRequest.response to get JSON, assuming the server response is actually JSON, leaving something like:

oReq.responseType = "json";

var resposta = oReq.response;

console.log(oReq.response);

---

Javascript/Ecmascript asynchronous and callback

To understand a little better about how callbacks run, read on:

• What is the real advantage of using a Callback and what is thread/multithread?

Answer 2

AJAX(Asynchronous Javascript and XML) is a technique that uses javascript to send asynchronous requests to a server, making pages and web systems (of the time and today) more interactive.

The term was wedge by Jesse James Garrett in 2005 in Article Ajax: A New Approach to Web Applications

Answer 3

To implement the Exchange web interface (OWA) without using page exchange to load new content, Microsoft created an interface in its MSXML component that allowed sending a request over HTTP and receiving an asynchronous response. At the time what was bombarding was XML and the interface was named Xmlhttprequest, but it does not require in any way that the returned content is XML.

Other browser developers adopted the interface and it exploded when Google launched Google Maps. Later it was packaged in Jquery which greatly facilitated its use portability between browsers.

So, to answer the question, I think AJAX is best qualified as a technique than as a technology. It’s certainly not a programming language. The technology would be the interface for asynchronous requests, which browsers originally did not support.

The complete story is in Wikipedia, as usual.

Answer 4

AJAX (in English Tosynchronous JavaScript and XML, or Javascript and asynchronous XML) is a term used for asynchronous communication practices between a web application and a corresponding back-end.

In this definition, AJAX is a protocol (in the sense that it defines a behavior for data exchange), its implementation a canal (where requests are made and responses received) and their use a practising (asynchronous requests and their treatment).

Answer 5

The Question Being More Specific:

AJAX is a Recourse javascript.

In which you can :

• Refresh the web page without reloading the page
• Send data to a server - after the page is already loaded.
• Receiving data from a server - after the page is already loaded.

Answer 6

It is a method or process for using Javascript and XML (or JSON) in communicating pages with users.