AJAX
AJAX has changed the world of web development. Look at digg, facebook and gmail, thery are good examples to show the capability of AJAX. AJAX can create a highly responsive web interface and increase the user experience.
AJAX is abbrieviated from Asynchrounous javascript and XML. It's not a new technology, but the implementation of a group of technologies to achieve a seamless interaction between client and server.
Typically, xhtml and css to present the information, javascript is used to handle user interactions, and a server side language to perform the users' requests (and normally return data in XML format, in this tutorial, we won't do that), and it all is happening in the background using the Javascript XMLHttpRequest. Javascript plays a main role tie all these technologies together and create the asynchronous interaction between client ans server.
Advantages:- Reduce connections and bandwidth to the server, images, scripts, stylesheets only need to be downloaded once
- Reduce loading timew. User doesnt have to load pages again and again, it all happens in a same page!
- Increase responsiveness and end user experiences.
- Always provide feedback to user. Let user know the server is processing the request. Indicate that using message or loading icon.
- Prepare a plan to those users without Javascript support.
Introduction
So, you know about the goodness of AJAX. Let's learn a simple way to implement it.
In this tutorial, we will learn form submission using jQuery without navigate out from the page. It accepts user input, processes it and sends it to a php file called "process.php". The PHP script will send a notification email to the recipient. Of course, in case browser couldn't support javascript/XMLHttpRequest, we have a second plan ready, the form will submit the data using the normal form submission.
How do we do that? Easy, we specified POST and ACTION attributes in the FORM element, if browsers couldn't support it, that will submit the form straight away. If the browsers could support it, the javascript will cancel the submit button default behaviour. And we need to code the PHP script to support both GET and POST methods and produce the result accordingly.
1. HTML
In this sample, I'll keep everything as simple as possible. This is how it looks like
<div class="block"> <div class="done"> <b>Thank you !</b> We have received your message. </div> <div class="form"> <form method="post" action="process.php"> <div class="element"> <label>Name</label> <input type="text" name="name" class="text" /> </div> <div class="element"> <label>Email</label> <input type="text" name="email" class="text" /> </div> <div class="element"> <label>Website</label> <input type="text" name="website" class="text" /> </div> <div class="element"> <label>Comment</label> <textarea name="comment" class="text textarea" /></textarea> </div> <div class="element"> <input type="submit" id="submit"/> <div class="loading"></div> </div> </form> </div> </div> <div class="clear"></div>
2. CSS
I'm using CSS to make the 2 columns layout - LABEL and Form Elements. Also, some important classes:
- .hightlight: Error indicator. if user had not entered anything in the textfield, it will highlight it and display an error icon
- .loading: Loading animation icon. After user clicked on submit, if no errors were found, this icon will be displayed next to the submit button
- .done: Success message. If the form is submitted successfully, display show this class
body{text-align:center;} .clear {clear:both} .block { width:400px; margin:0 auto; text-align:left; } .element * { padding:5px; margin:2px; font-family:arial; font-size:12px; } .element label { float:left; width:75px; font-weight:700 } .element input.text { float:left; width:270px; padding-left:20px; } .element .textarea { height:120px; width:270px; padding-left:20px; } .element .hightlight { border:2px solid #9F1319; background:url(iconCaution.gif) no-repeat 2px } .element #submit { float:right; margin-right:10px; } .loading { float:right; background:url(ajax-loader.gif) no-repeat 1px; height:28px; width:28px; display:none; } .done { background:url(iconIdea.gif) no-repeat 2px; padding-left:20px; font-family:arial; font-size:12px; width:70%; margin:20px auto; display:none }
3. Javascript
Finally, the Javascript code. I have added comments in each line to explain what it does.
First, we need a simple validation to ensure user has key in something. We can add more validations, like, email validation, valid character validation, length validation and so on. And it's a good practise to encode the data into URL friendly format as well.
What the code does:
- Get user's input
- Validate the data, if error found, add the hightlight class, and stop the script
- If no errors were found, all text field will be disabled and format the data to be passed to jQuery ajax method
- jQuery will appened the data to process.php, so it will look something like this:
http://[your-website-url]/process.php?name=kevin&email=kevin@test.com&website=http://www.queness.com&comment=Testing%20of%20Ajax%20Form%20Submission
in fact, you can execute the process.php with that url. - process.php will return either 1 or 0, if 1 it meant mail was sent successfully, otherwise, mail was not sent.
- If suceed, the form will be hidden and a message is displayed.
$(document).ready(function() { //if submit button is clicked $('#submit').click(function () { //Get the data from all the fields var name = $('input[name=name]'); var email = $('input[name=email]'); var website = $('input[name=website]'); var comment = $('textarea[name=comment]'); //Simple validation to make sure user entered something //If error found, add hightlight class to the text field if (name.val()=='') { name.addClass('hightlight'); return false; } else name.removeClass('hightlight'); if (email.val()=='') { email.addClass('hightlight'); return false; } else email.removeClass('hightlight'); if (comment.val()=='') { comment.addClass('hightlight'); return false; } else comment.removeClass('hightlight'); //organize the data properly var data = 'name=' + name.val() + '&email=' + email.val() + '&website=' + website.val() + '&comment=' + encodeURIComponent(comment.val()); //disabled all the text fields $('.text').attr('disabled','true'); //show the loading sign $('.loading').show(); //start the ajax $.ajax({ //this is the php file that processes the data and send mail url: "process.php", //GET method is used type: "GET", //pass the data data: data, //Do not cache the page cache: false, //success success: function (html) { //if process.php returned 1/true (send mail success) if (html==1) { //hide the form $('.form').fadeOut('slow'); //show the success message $('.done').fadeIn('slow'); //if process.php returned 0/false (send mail failed) } else alert('Sorry, unexpected error. Please try again later.'); } }); //cancel the submit button default behaviours return false; }); });
4. PHP
This PHP code can accomodate different type of submissions (POST and GET). If the user submitted the form using jQuery, process.php will get the data from GET. and if the browser couldn't run javascript, the data will be sent using POST. What it does:
- Retrieve user's input from either GET or POST method
- If POST, set the $post variable to 1. This is to display the message instead of return the result
- Then, perform the server side validation if the form was submitted using POST
- If no errors were found, organize the data into a html email template and send it to the email we have specified.
- Display the message if POST is used. Display result (either 1 or 0) if GET is used
<?php //Retrieve form data. //GET - user submitted data using AJAX //POST - in case user does not support javascript, we'll use POST instead $name = ($_GET['name']) ? $_GET['name'] : $_POST['name']; $email = ($_GET['email']) ?$_GET['email'] : $_POST['email']; $website = ($_GET['website']) ?$_GET['website'] : $_POST['website']; $comment = ($_GET['comment']) ?$_GET['comment'] : $_POST['comment']; //flag to indicate which method it uses. If POST set it to 1 if ($_POST) $post=1; //Simple server side validation for POST data, of course, //you should validate the email if (!$name) $errors[count($errors)] = 'Please enter your name.'; if (!$email) $errors[count($errors)] = 'Please enter your email.'; if (!$comment) $errors[count($errors)] = 'Please enter your comment.'; //if the errors array is empty, send the mail if (!$errors) { //recipient - change this to your name and email $to = 'Your Name <your@email.com>'; //sender $from = $name . ' <' . $email . '>'; //subject and the html message $subject = 'Comment from ' . $name; $message = ' <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> <html xmlns="http://www.w3.org/1999/xhtml"> <head></head> <body> <table> <tr><td>Name</td><td>' . $name . '</td></tr> <tr><td>Email</td><td>' . $email . '</td></tr> <tr><td>Website</td><td>' . $website . '</td></tr> <tr><td>Comment</td><td>' . nl2br($comment) . '</td></tr> </table> </body> </html>'; //send the mail $result = sendmail($to, $subject, $message, $from); //if POST was used, display the message straight away if ($_POST) { if ($result) echo 'Thank you! We have received your message.'; else echo 'Sorry, unexpected error. Please try again later'; //else if GET was used, return the boolean value so that //ajax script can react accordingly //1 means success, 0 means failed } else { echo $result; } //if the errors array has values } else { //display the errors message for ($i=0; $i<count($errors); $i++) echo $errors[$i] . '<br/>'; echo '<a href="form.php">Back</a>'; exit; } //Simple mail function with HTML header function sendmail($to, $subject, $message, $from) { $headers = "MIME-Version: 1.0" . "\r\n"; $headers .= "Content-type:text/html;charset=iso-8859-1" . "\r\n"; $headers .= 'From: ' . $from . "\r\n"; $result = mail($to,$subject,$message,$headers); if ($result) return 1; else return 0; } ?>
Conclusion
Now you know how to build a ajax based form submission that will work even if the browser doesnt support javascript using jQuery. Make sure you check out the demo and download the source code to play with it. Last but not least, I need your support :) If you like this article, please help me to promote it by adding this post into your bookmark. Or you can subscribe to my RSS for more posts. Thanks!
Comments will be moderated and
rel="nofollow"
will be added to all links. You can wrap your coding with[code][/code]
to make use of built-in syntax highlighter.I think I have most of everything working. Validation works fine, when I click submit, the loader .gif shows, but then the page loads process.php and just displays a 1. Any help would be greatly appreciated.
Thanks for the great script. Just got one question, how do you able to input details again after you submit the form? Because when you refreshed the site, it won't allow you type again but you can resubmit the details.
Any idea?
Thanks!
It's me again. I think the problem is with firefox since it's work with safari but haven't check the form in IE. I just remove this code in the script
//disabled all the text fields
$('.text').attr('disabled','true');
and it's work like a charm. I can input details again after I refresh the page. I don't know if there something going wrong with the script after removing that lines of code.
Again nice scripts. Thanks!
Thanks for this great tutorial, I implemented my site's add comment part with ajax as you instructed. However, on $.ajax even though it succesfully calls php file and do everything as I need but never return with html. So cannot fadeOut loading div or get any alert about exception. What could be the reason? Thanks in advance.
Thanks for the script. Working just amazing! The only problem - spam. Any solution for that?
http://stackoverflow.com/questions/166221/how-can-i-upload-files-asynchronously-with-jquery
There are plenty of already made ajax file upload, you might want to check them out.
Thanks!
give the <form> an ID, eg #form, then you can use $('#form').serialize() which will construct data and submit it to the PHP script
http://api.jquery.com/serialize/
but I have a question on the same page I did put a contact form below and separately in another part of the input page to put a email to subscribe but does not work and copy the code i email some how I can get right comflicto this thanks and good work .
$('#form1 .submit').click(function () ....
$('#form2 .submit').click(function () ....
basically, you need to duplicate the script and modify to adapt to each of your form.
$to = 'Your Name <your@email.com>, Your Name <your@email.com>';