Showing posts with label tutorial. Show all posts
Showing posts with label tutorial. Show all posts

Sunday, December 14, 2008

Saturday, November 1, 2008

AjaxForm

After a long break in the development process of those Ajax components I promised to release here, I eventually, convinced myself to put the latest but still incomplete version of AjaxForm (the first component I decided to design and develop) here. I hope you enjoy its design and ease of use, that let you ajaxify a form by creating an object and calling some methods of that object from both client side scripts and the script which is coming from the server side result.
e.g.

var ajaxForm = new AjaxForm("frmEditUser", "edituser.act.php", "loader1.gif", "editBoard");
ajaxForm.focusForm();

But don't forget that all of these components which I'm working on are based on Prototype.js framework.

So in all examples I assume that you have the following line in your document's head section.


<script type="text/javascript" src="prototype.js"></script>

You can download the current version of AjaxForm here.

The design is based on the idea that each form has 4 main elements to be working as an web 2.0 form. (it is my idea, you may disagree with that)
  1. The form itself - HTML element (tag) of form, so we need to pass the ID of the form element to the AjaxForm object.
  2. The server side script which the forms's data will be sent to, so we pass the URL of the script to the object.
  3. The image that should be displayed as a loading animation while the user is waiting to receive the server result. We need to pass the URL of the image file to the AjaxForm object.
  4. The exact portion of the page that the animation image should be displayed, and also the place that other potential messages to the users should be displayed. So we pass the ID of an HTML element to the object.
The 4th factor could be divided to 2 separated factors, one HTML element for the animation image and one for the user messages, but I decided to have one for both, in order to keep the concept simple. I may add the feature in the final version. Anyway, according to these 4 factors, we can create an object of AjaxForm class like the following codes.

Example1

First add the followings to the head section of your page:

<script type="text/javascript" src="prototype.js"></script>
<script type="text/javascript" src="ajaxform.js"></script>


The HTML form.

<form id="form1">
username:
<input type="text" id="username" name="username" />
<br />
password:
<input type="password" id="password" name="password" />
<br />
<input type="submit" value="send" />
<input type="reset" value="reset" />
</form>


The place-holder for messages and the animation image.

<div id="board"></div>


Main part (instantiating the object)

<script type="text/javascript">
<!--
var ajaxForm = new AjaxForm("form1", "action1.php", "loader1.gif", "board");
ajaxForm.focusForm();
//-->
</script>

Don't forget to locate the following files in the same directory as your page directory:
  • prototype.js - you can download it here.
  • ajaxform.js - download it here.
  • loader1.gif - any gif animation
  • action1.php - a php file that will handle the request data

Now it's time to write the server side code. The server side script could be developed in any technology such as Java servlet, JSP, PHP, PERL, Python, ASP, ASP .NET and ...
In this example I write it using PHP (action1.php).

action1.php

<?php
$username = $_POST['username'];
$password = $_POST['password'];

$login = false;

if (empty($username)) {
$message = "You should enter your username!";
$color = "red";
} else if (empty($password)) {
$message = "You should enter your password!";
$color = "#FF7000";
} else if($username == 'ehsun' && $password == '7') {
$login = true;
$message = "You have logged in successfully.";
$color = "#335599";
} else {
$message = "Your username or password is incorrect!";
$color = "#9F9000";
}

echo "<script>";
echo "ajaxForm.showMessage('$message', '$color');";

if ($login) {
echo "ajaxForm.hideForm();";
} else {
echo "ajaxForm.focusForm();";
}

echo "</script>";

sleep(3);
?>


The sleep command is for simulating the delay! you don't need it in the real codes.

As you may noticed you have access to the AjaxForm object which has been created in the client side from the JavaScript code which is coming from server side script, that is very useful feature!
The AjaxForm has some other methods that I will explain in the next posts. Please give me your suggestions.

Saturday, December 22, 2007

Google Suggest Tutorial

In the web sites and web applications most of the users are not aware of the exact and complete name of terms they are searching for! So it is a good idea to give them suggestion while they are trying to write the name of the desired words. Similar to what is happening in Google suggest.

In this tutorial we will do the same thing for a search in a group of people whose information are stored in a table of database. The same as the previous tutorials we use prototype.js as Ajax/DOM framework.

Since the steps are too simple and so similar to the previous tutorials, I let you download it and check it out by yourself! ;)

Good Luck!

Tuesday, December 11, 2007

Ajax Chat - Using Prototype & PHP

In the past years chat rooms were so rare in the websites and only those website which needed it were using chat facilities. Most of those chat rooms were developed by means of Java Applet technology hence the client browser had to be Java-enabled in order to use the chat rooms. After a while flash chat rooms came in the picture but they had the same drawback since the client needs to have the Flash player plugin installed in order to use the chat rooms.
Recently the Ajax-enabled chat rooms have come to the websites even the personal websites. They are so light, easy to develop and don't need any special software or prerequisites on the clients' browsers.

In this tutorial we will learn how to develop a very simple Ajax-enabled chat room based on PHP 5 server-side scripting language and Prototype JavaScript framework.

You can develop this chat room following the steps bellow or download it here.

1. JavaScript Message class and one utility function
Create 2 folders called php and js. Copy the prototype.js file in the js folder.
Create a new javascript file called chat.js which contains the following code and put it in the js folder.

var Message = Class.create();
Message.prototype = {
initialize: function(id, timestamp, serverTimestamp, nickname, text) {
this.id = id;
this.timestamp = timestamp;
this.serverTimestamp = serverTimestamp;
this.nickname = nickname;
this.text = text;
},
};


function removeChildrenOf(s) {
while (s.hasChildNodes())
s.removeChild(s.childNodes[0]);
}


2. PHP Message class
Create a new php file called message.class.php which contains the following code and put it in the php folder.


<?php
class Message {

const MAX_TEXT_LENGTH = 100;
const MAX_NICKNAME_LENGTH = 20;

// ...........................................

private $id;
private $timestamp;
private $serverTimestamp;
private $nickname;
private $text;

// ...........................................

public function __construct($id = 0, $timestamp = 0, $serverTimestamp, $nickname = "", $text = "") {
$this->id = $id;
$this->timestamp = $timestamp;
$this->serverTimestamp = $serverTimestamp;
$this->nickname = $nickname;
$this->text = $text;
}

// ...........................................

public function setId($id) {
$this->id = $id;
}

public function getId() {
return $this->id;
}

public function setTimestamp($timestamp) {
$this->timestamp = $timestamp;
}

public function getTimestamp() {
return $this->timestamp;
}

public function setServerTimestamp($serverTimestamp) {
$this->serverTimestamp= $serverTimestamp;
}

public function getServerTimestamp() {
return $this->serverTimestamp;
}

public function setText($text) {
if(strlen($text) > self::MAX_TEXT_LENGTH)
echo "Error: Text is too long! Maximum is ".self::MAX_TEXT_LENGTH;
else
$this->text = $text;
}

public function getText() {
return $this->text;
}

public function setNickname($nickname) {
if(strlen($text) > self::MAX_NICKNAME_LENGTH)
echo "Error: Nickname is too long! Maximum is ".self::MAX_NICKNAME_LENGTH;
else
$this->nickname = $nickname;
}

public function getNickname() {
return $this->nickname;
}
}
?>


3. Database, Tables and Configuration
Create a database in your mysql DBMS and run the following query on it in order to create the message table.


CREATE TABLE `message` (
`id` int(10) unsigned NOT NULL auto_increment,
`timestamp` bigint(20) unsigned default NULL,
`text` varchar(100) default NULL,
`serverTimestamp` bigint(20) unsigned default NULL,
`nickname` varchar(20) default NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=7 DEFAULT CHARSET=utf8;


Create a php file called config.inc.php which contains the following code and put it in the php folder.
Don't forget to write database name, username and password of your mySql server instead of corresponding parameters in this file.

<?php
define("DB_HOST", "localhost");
define("DB_USERNAME", "root");
define("DB_PASSWORD", "ebic");
define("DB_NAME", "chat");
?>


4. Send Message server-side script

Create a php file called send.php which contains the following code, don't put it in any folder, let it be in the root folder of your website.


<?php
include_once('./php/config.inc.php');

$mysqli = new mysqli(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_NAME);

if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}

$text = isset($_POST['text']) ? $_POST['text'] : "";
$timestamp = isset($_POST['timestamp']) ? $_POST['timestamp'] : 0;
$serverTimestamp = isset($_POST['serverTimestamp']) ? $_POST['serverTimestamp'] : 0;
$nickname = isset($_POST['nickname']) ? $_POST['nickname'] : "";

$sql = "INSERT INTO message (text, nickname, timestamp, serverTimestamp)
VALUES('$text', '$nickname', '$timestamp', '$serverTimestamp')";

if (!$mysqli->query($sql)) {
echo "Error in query";
}

?>


5. Receive Messages server-side script
Create a php file called get.php which contains the following code, don't put it in any folder, let it be in the root folder of your website.


<?php
include_once('./php/config.inc.php');

header('Content-type: text/xml');

$mysqli = new mysqli(DB_HOST, DB_USERNAME, DB_PASSWORD, DB_NAME);

if (mysqli_connect_errno()) {
printf("Connect failed: %s\n", mysqli_connect_error());
exit();
}

echo "<messages>";

$timestamp = time();
$sql = "DELETE FROM message WHERE $timestamp - serverTimestamp > 1000 ";

if (!$mysqli->query($sql)) {
echo "Error in query";
} else {
$sql = "SELECT * FROM message";
if (!$result = $mysqli->query($sql)) {
echo "Error in query";
} else {
while($record = $result->fetch_assoc()) {
echo "<message>";

echo "<id>";
echo $record['id'];
echo "</id>";

echo "<timestamp>";
echo $record['timestamp'];
echo "</timestamp>";

echo "<serverTimestamp>";
echo $record['serverTimestamp'];
echo "</serverTimestamp>";

echo "<text>";
echo $record['text'];
echo "</text>";

echo "<nickname>";
echo $record['nickname'];
echo "</nickname>";

echo "</message>";
}
}
}

echo"</messages>";

?>


6. Utility server-side script for getting the server timestamp
Create a php file called timestamp.php which contains the following code, don't put it in any folder, let it be in the root folder of your website.


<?php
echo mktime();
?>


7. Client script for sending and getting (main html page)
Create a html file called index.html which contains the following code, don't put it in any folder, let it be in the root folder of your website.


<?xml version="1.0" encoding="UTF-8" ?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
<head>
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8" />
<title>Chat Room (Shout Box)</title>
<script type="text/javascript" src="js/prototype.js"></script>
<script type="text/javascript" src="js/chat.js"></script>

<script type="text/javascript"><!--
<!--

var serverTimestamp = 0;
var messages = new Array(10000);
var msgCount = 0;

function existInArray(msg) {
for(i = 0; i < msgCount; i++) {
if(msg.timestamp == messages[i].timestamp)
if(msg.serverTimestamp == messages[i].serverTimestamp)
return true;
}
return false;
}

function getMessages() {
new Ajax.Request('get.php?ts=' + new Date().getTime(), {
onSuccess: function(transport) {
var xml = transport.responseXML;
var msgNodes = xml.documentElement.childNodes;
for(i = 0; i < msgNodes.length; i++) {
var id = msgNodes[i].getElementsByTagName("id")[0].firstChild.nodeValue;
var nickname = msgNodes[i].getElementsByTagName("nickname")[0].firstChild.nodeValue;
var text = msgNodes[i].getElementsByTagName("text")[0].firstChild.nodeValue;
var timestamp = msgNodes[i].getElementsByTagName("timestamp")[0].firstChild.nodeValue;
var serverTimestamp = msgNodes[i].getElementsByTagName("serverTimestamp")[0].firstChild.nodeValue;
var msg = new Message(id, timestamp, serverTimestamp, nickname, text);
//alert(i);
if(!existInArray(msg)) {
messages[msgCount++] = msg;
}
}
}
});

showMessages();
setTimeout("getMessages()", 4000);
}

function updateServerTimestamp() {
new Ajax.Request('timestamp.php?ts=' + new Date().getTime(), {
onSuccess: function(transport) {
serverTimestamp = transport.responseText;
}
});
}

function showMessages() {
var board = $('board');
removeChildrenOf(board);
for(i = 0; i < msgCount; i++) {
var msgView = document.createElement("div");
var msg = messages[i];
var date = new Date(parseInt(msg.timestamp, 10));
msgView.innerHTML = msg.nickname + " <small>(" + date.getHours() + ":" + date.getMinutes() + ":" + date.getSeconds() + ")</small>: " + msg.text;
board.appendChild(msgView);
}
board.scrollTop = board.scrollHeight;
}

function sendMessage(msg) {
new Ajax.Request('send.php', {
method: 'post',
parameters: {
text: msg.text,
nickname: msg.nickname,
timestamp: msg.timestamp,
serverTimestamp: msg.serverTimestamp
},
onFailure: function() {
sendMessage(msg);
}
});

}

function doMessage() {
if ($F("message").length > 0) {
var board = $('board');
var msg = new Message(0, new Date().getTime(), serverTimestamp, $F('name'), $F("message"));
//alert(msg.timestamp);
messages[msgCount++] = msg;
showMessages();
sendMessage(msg);
board.scrollTop = board.scrollHeight;
}
$('message').clear();
$('message').focus();
updateServerTimestamp();
}

Event.observe(window, 'load', function() {
updateServerTimestamp();
getMessages();
});


//-->
</script>


<style>
<!--

#board {
width: 400px;
border: inset 2px;
height: 300px;
padding: 2px;
overflow: auto;
}

-->
</style>
</head>
<body>

<h1>Chat Room</h1>

<form action="" onsubmit="return false;">
<div id="board"></div>
<br />
<label>Nickname:</label>
<input type="text" name="name" id="name" maxlength="20" />
<br />
<label>Message:</label>
<input type="text" id="message" name="message" maxlength="100" size="45"/>
<input type="submit" value="Send" name="send" onclick="doMessage()"/>
</form>
<br />
<br />
<a href="http://ehsun7b.blogspot.com">ehsun7b.blogspot.com</a>
</body>
</html>



Enjoy chatting in your own website!

Monday, November 12, 2007

Uploading Files, Using Ajax

As you may know it is impossible to upload files to the server using XHR! And the easiest way to upload them in an AJAX way is to use Iframes.
But be aware that uploading files through the XMLHttpRequests is NOT impossible, although it has some security issues.

So we will see how to develop a simple Ajax based upload using Iframe. The upload process by itself doesn't have anything complicated. You can do it in a synchronous style using any kind of server-side technology such as PHP, JSP, ASP or...
It will happen in a document which is displaying on the page using an Iframe so from the whole document point of view it will upload the file as an asynchronous request. But the thing is so important here is the JavaScript integration which is required between the main document and the uploading document (the document inside the Iframe) for showing some progress or loading animations.

In this tutorial I use PHP as server-side language and prototype.js as Ajax/JavaScript framwork.
You can download this script here, or do it yourself step by step:

1. index.html
Create a new file called index.html and write the following code in the body:


<h2>Upload file</h2>
<iframe frameborder=0 src="upload.php"></iframe>
<div id="board"></div>
<div id="images"></div>


The first DIV with ID="board" is for some messages which will be received before/after the upload process from the uploading document (the document inside th IFrame).
And the second one is for displaying uploaded photos. (If the uploaded files are photos!)


2. upload.php
Create another file called upload.php and write the following code inside it:

<?php

?>
<script type="text/javascript" src="js/prototype.js"></script>

<script type="text/javascript">

<!--
var par = parent.content.document;
var board = par.getElementById("board");
var images = par.getElementById("images");

function removeChildrenOf(s) {
while (s.hasChildNodes())
s.removeChild(s.childNodes[0]);
}

function message(msg, color) {
var message = par.createTextNode(msg);
board.setAttribute("style", "color: " + color);
board.appendChild(message);
}

function upload() {
var loader = par.createElement("img");
loader.setAttribute("src", "img/progress.gif");
removeChildrenOf(board);
board.appendChild(loader);
document.forms['photoform'].submit();
}

function addPhoto(source) {
var img = par.createElement("img");
img.setAttribute("src", "img/" + source);
images.appendChild(img);
}

<?php
if(isset($_FILES['file'])) {
sleep(1);
echo "removeChildrenOf(board);";
$ext = substr($_FILES['file']['name'], strrpos($_FILES['file']['name'], '.') + 1);

if((strtoupper($ext) == "JPG" || strtoupper($ext) == "GIF") || (strtoupper($ext) == "PNG" || strtoupper($ext) == "BMP")) {
copy($_FILES['file']['tmp_name'],'img/'.$_FILES['file']['name']);
echo "message('The photo was uploaded successfully.', '#22AA44'); ";
echo "addPhoto('".$_FILES['file']['name']."');";
} else {
echo "message('Invalid format! The valid formats are: JPG, GIF, PNG and BMP.', '#ff4444'); ";
}
}
?>

//-->
</script>

<form action="" method="post" id="photoform" enctype="multipart/form-data">
<input type="file" name="file" onchange="upload()"/>
</form>



3. The other needed files
Don't forget to create a new folder called js and copy the prototype.js file there.
And create another folder called img and copy a GIF animation called progress.gif there.

Enjoy uploading photos asynchronously!


Saturday, October 27, 2007

Ajax clock, an alive clock using the server time

In this tutorial we will see how easy is to develop a simple clock using the prototype Ajax classes, specifically Ajax.PeriodicalUpdater class.

You can download this tutorial files here.

Developing a JavaScript clock is not so difficult, and there are a bunch of them available in the net. But sometimes we need to show the server's time on the clock, instead of using the clients' own machine time. So the solution is Ajax if we want to have an interactive (alive) clock on the page which is showing the server's time without refreshing the page again and again.


1.
Create a html file and write the following code :

in the head section:



in body section:




2.
Create a PHP file called clock.php containing the following code:




3.
Create a floder called js besides these files and copy the prototype.js in it. You can download the latest version of prototype framework here.

Thats it! Copy all the files in the apache htdocs folder and enjoy!


Explanation:

We have a div with id="clock" in the html body which is our placeholder for displaying the time.
In the JavaScript section we have created a new object of class Ajax.PeriodicalUpdater which is one of the Ajax classes provided by prototype framework.
According to the prototype document:

This object addresses the common need of periodical update, which is used by all sorts of “polling” mechanisms (e.g. in an online chatroom or an online mail client).

So we don't need to provide a mechanism for fetching the time again and again, this object will repeat its job automatically based on its frequency option in the options parameter.
The first parameter is the id of the HTML element which will show the result and the second one is the URL for the request (XMLHttpRequest).

Enjoy Ajax!