Subin Sebastian Subin Sebastian - 4 months ago 36
jQuery Question

Sending and receiving JSON data | PhoneGap + Jquery Mobile app using ajax()

I'm developing a PhoneGap application with jQuery Mobile 1.3.1 & jQuery JavaScript Library v1.9.1. I have a login form with a username and a password. There is a JSON api which can send and receive JSON data for processing the login.

I use the following JavaScript for the ajax login.

$('#submit').bind('click', function(e) {
e.preventDefault();
$.ajax({
type : "POST",
url : "http://domainx/public/login",
xhrFields : {withCredentials: true},
crossDomain: true,
beforeSend : function() {$.mobile.showPageLoadingMsg();},
complete : function() {$.mobile.hidePageLoadingMsg();},
data : {username : 'subin', password : 'passwordx'},
dataType : 'json',
success : function(response) {
console.error(JSON.stringify(response));
},
error : function() {
console.error("error");
}
});
});


Here is my html code for the login form.

<div data-role="content">
<form id="login-form" data-ajax="false" method="post">
<fieldset>
<input type="text" name="username" id="username" value="subin" placeholder="Username">
<input type="password" name="password" id="password" value="passwordx" placeholder="Password">
<input type="button" data-theme="b" name="submit" id="submit" value="Enter" data-icon="plus">
</fieldset>
</form>
</div>


But this just don't work. The server returns login failure error, although it works fine for other apps.

Answer

You have several error is your code:

  1. Change date to data

    data       : {username : 'subin', password : 'passwordx'},
    
  2. Remove this line, it will prevent Phonegap from successful posting:

    xhrFields  : {withCredentials: true},
    
  3. In your beforeSend and complete use this function to show loader:

    $.mobile.loading('show');
    

    and

    $.mobile.loading('hide');
    

    your current ones are deprecated in jQuery 1.2+.

Your final code should look like this:

$.ajax({
    type       : "POST",
    url        : "http://domain/public/login",
    crossDomain: true,
    beforeSend : function() {$.mobile.loading('show')},
    complete   : function() {$.mobile.loading('hide')},
    data       : {username : 'subin', password : 'passwordx'},
    dataType   : 'json',
    success    : function(response) {
        //console.error(JSON.stringify(response));
        alert('Works!');
    },
    error      : function() {
        //console.error("error");
        alert('Now working!');                  
    }
});     

Proof that it is working, just run it from the disk and not from a server because you will get a CROSS domain error:

<!DOCTYPE html>
<html>
    <head>
        <title>jQM Complex Demo</title>
        <meta http-equiv='Content-Type' content='text/html; charset=utf-8'/>
        <meta name="viewport" content="width=device-width; initial-scale=1.0; maximum-scale=1.0; minimum-scale=1.0; user-scalable=no; target-densityDpi=device-dpi"/>
        <link rel="stylesheet" href="http://code.jquery.com/mobile/1.3.1/jquery.mobile-1.3.1.min.css" />
        <script src="http://code.jquery.com/jquery-1.9.1.min.js"></script>          
        <script src="http://code.jquery.com/mobile/1.3.1/jquery.mobile-1.3.1.min.js"></script>    
        <script>
    $.ajax({
        type       : "POST",
        url        : "http://domain/public/login",
        crossDomain: true,
        beforeSend : function() {$.mobile.loading('show')},
        complete   : function() {$.mobile.loading('hide')},
        data       : {username : 'subin', password : 'passwordx'},
        dataType   : 'json',
        success    : function(response) {
            //console.error(JSON.stringify(response));
            alert('Works!');
        },
        error      : function() {
            //console.error("error");
            alert('Not working!');                  
        }
    });     
        </script>
    </head>
    <body>
        <div data-role="page" id="index">
            <div data-theme="b" data-role="header">
                <h1>Index page</h1>
            </div>

            <div data-role="content">

            </div>
        </div>    
    </body>
</html>   
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