CODEWITHSUNDEEP
javascriptajaxlong-polling
Samuel
Samuel

Reputation: 13

What is the best way to do long polling in AJAX requests in JavaScript without JQuery?

hi after searching in the net about how to use the long polling in JavaScript I ended up with three ways, they are mentioned here briefly,but they are implemented using JQuery. I am confused which one to use in case that the AJAX request that I send to the server is asynchronous GET request ,and I don't know how many time it could take.

here is an example AJAX request:

function asynchGETRequest(method,url){
    var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function() {
    if (this.readyState == 4 && this.status == 200) {
        console.log("ok");
    }
    };
    xhttp.open(method, url, true);
    xhttp.send();
    return (xhttp.responseText);
}


var clientFunctions={
     getAnswers : function(callback){
        var res=asynchGETRequest("GET", "http://localhost:9000/answers");
        callback(JSON.stringify(res));
     }
}

 clientFunctions.getAnswers (function(){
       //do some code here after the ajax request is ended
 });

can some one guide me please?

Upvotes: 0

Views: 1762

Answers (1)

Samuel
Samuel

Reputation: 13

I think I found the solution here 

function loadFile(sUrl, timeout, callback){

    var args = arguments.slice(3);
    var xhr = new XMLHttpRequest();
    xhr.ontimeout = function () {
        console.error("The request for " + url + " timed out.");
    };
    xhr.onload = function() {
        if (xhr.readyState === 4) {
            if (xhr.status === 200) {
                callback.apply(xhr, args);
            } else {
                console.error(xhr.statusText);
            }
        }
    };
    xhr.open("GET", url, true);
    xhr.timeout = timeout;
    xhr.send(null);
}

Upvotes: 1

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