Read Blogger Feeds Using AJAX Callback Function - Amit Padhiyar (Saatody)

This article is all about read AJAX callback function. This callback function gives output in XML and JSON formats. This will also help us to make blogger widgets without blogger tags like <b:widget>.

The callback function read blogger feeds using readJSON() and readXML() functions. Write entire program between <script> tag.

<script>

</script>

Create callback function in AJAX

function read(_url, _function){
    var xhttp = new XMLHttpRequest();
    xhttp.onreadystatechange = function(){
        if (this.readyState == 4 && this.status == 200){
            _function(this);
        }
    };
    xhttp.open('GET',_url,true);
    xhttp.send();
}

Create callback function for JSON format

function readJSON(_url, _function){
    read(_url + "?alt=json", _function);
}

Create callback function for XML format

function readXML(_url, _function){
    read(_url ,_function);
}

Create function that write output in browser console

function writeInConsole(xhttp){
    var data = xhttp.responseText;
    console.log(data);
}

Call functions and get output in browser console

readJSON("https://demo.blogspot.com/feeds/posts/default",writeInConsole);
readXML("https://demo.blogspot.com/feeds/posts/default",writeInConsole);

Look at entire script

<script>

    function read(_url, _function){
        var xhttp = new XMLHttpRequest();
        xhttp.onreadystatechange = function(){
            if (this.readyState == 4 && this.status == 200){
                _function(this);
            }
        };
        xhttp.open('GET',_url,true);
        xhttp.send();
    }
    
    function readJSON(_url, _function){
        read(_url + "?alt=json", _function);
    }
    
    function readXML(_url, _function){
        read(_url ,_function);
    }
    
    function writeInConsole(xhttp){
        var data = xhttp.responseText;
        console.log(data);
    }
    
    readJSON("https://demo.blogspot.com/feeds/posts/default", writeInConsole);
    readXML("https://demo.blogspot.com/feeds/posts/default", writeInConsole);

</script>