Using Click Interceptions with a Database-Driven Application - The full source code of the improved MySQL-driven application
(Page 4 of 4 )
As I promised you in the section that you just read, here are all of the source files that compose this basic MySQL-driven application after the behavior of the user detail web pages has been enriched by means of the click-interception approach:
(definition of 'list_users.htm' file)
<!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=iso-8859-1" />
<title>Building with AJAX an user detail page using click interceptions</title>
<style type="text/css">
body{
padding: 0;
margin: 0;
background: #fff;
}
h1{
font: bold 18pt Arial, Helvetica, sans-serif;
color: #000;
}
h2{
font: bold 16pt Arial, Helvetica, sans-serif;
color: #000;
}
a:link,a:visited{
font: normal 10pt Arial, Helvetica, sans-serif;
color: #00f;
}
a:hover{
color: #f90;
}
p{
font: normal 10pt Arial, Helvetica, sans-serif;
color: #000;
}
#linkcontainer{
width: 300px;
padding: 5px;
background: #ffc;
}
#userviewer{
width: 300px;
}
</style>
<script language="javascript" type="text/javascript">
// send http requests
function sendHttpRequest(url,callbackFunc,respXml){
var xmlobj=null;
try{
xmlobj=new XMLHttpRequest();
}
catch(e){
try{
xmlobj=new ActiveXObject("Microsoft.XMLHTTP");
}
catch(e){
alert('AJAX is not supported by your browser!');
return false;
}
}
xmlobj.onreadystatechange=function(){
if(xmlobj.readyState==4){
if(xmlobj.status==200){
respXml?eval(callbackFunc+'(xmlobj.responseXML)'):eval(callbackFunc+'(xmlobj.responseText)');
}
}
}
// open socket connection
xmlobj.open('GET',url,true);
// send http header
xmlobj.setRequestHeader('Content-Type','text/html; charset=UTF-8');
// send http request
xmlobj.send(null);
}
// define 'displayUserDetails()' function
function displayUserDetails(userData){
var userviewer=document.getElementById('userviewer');
if(!userviewer){return};
userviewer.innerHTML=userData;
}
// define 'initializeLinks()' function
function initializeLinks(){
var lnkcont=document.getElementById('linkcontainer');
if(!lnkcont){return};
var links=lnkcont.getElementsByTagName('a');
if(!links){return};
for(var i=0;i<links.length;i++){
// use click interception to display user details on the same web page
links[i].onclick=function(){
sendHttpRequest('viewuserdetails.php?id='+this.href.split('=')[1],'displayUserDetails');
return false;
}
}
}
// call 'initializeLinks()' function when web page is loaded
window.onload=function(){
if(document.getElementById&&document.
getElementsByTagName&&document.createElement){
initializeLinks();
}
}
</script>
</head>
<body>
<h1>Example on building with AJAX an user detail page using click interception</h1>
<div id="linkcontainer">
<ul>
<li><a href="viewuserdetails.php?id=1" title="View details about Alejandro Gervasio...">View details about Alejandro Gervasio...</a></li>
<li><a href="viewuserdetails.php?id=2" title="View details about John Doe...">View details about John Doe...</a></li>
<li><a href="viewuserdetails.php?id=3" title="View details about Susan Norton...">View details about Susan Norton...</a></li>
<li><a href="viewuserdetails.php?id=4" title="View details about Marian Wilson...">View details about Marian Wilson...</a></li>
</ul>
</div>
<div id="userviewer"></div>
</body>
</html>
(definition of 'viewuserdetails.php' file)
<?php
// include classes
class MySQL{
private $host;
private $user;
private $password;
private $database;
private $conId;
// constructor
function __construct($options=array()){
if(!is_array($options)){
throw new Exception('Connection options must be an array');
}
foreach($options as $option=>$value){
if(empty($option)){
throw new Exception('Connection parameter cannot be empty');
}
$this->{$option}=$value;
}
$this->connectDb();
}
// private 'connectDb()' method
private function connectDb(){
if(!$this->conId=mysql_connect($this->host,$this->user,$this->password)){
throw new Exception('Error connecting to MySQL');
}
if(!mysql_select_db($this->database,$this->conId)){
throw new Exception('Error selecting database');
}
}
// public 'query()' method
public function query($sql){
if(!$result=mysql_query($sql)){
throw new Exception('Error running query '.$sql.' '.mysql_error());
}
return new Result($this,$result);
}
}
class Result{
private $mysql;
private $result;
// constructor
public function __construct($mysql,$result){
$this->mysql=$mysql;
$this->result=$result;
}
// public 'fetchRow()' method
public function fetchRow(){
return mysql_fetch_array($this->result,MYSQL_ASSOC);
}
// public 'count()' method
public function countRows(){
if(!$rows=mysql_num_rows($this->result)){
throw new Exception('Error counting rows');
}
return $rows;
}
// public 'get_insertId()' method
public function getInsertId(){
if(!$insId=mysql_insert_id($this->mysql->conId)){
throw new Exception('Error getting insert ID');
}
return $insId;
}
// public 'seek()' method
public function seekRow($row=0){
if(!is_int($row)&&$row<0){
throw new Exception('Invalid row parameter');
}
if(!$row=mysql_data_seek($this->mysql->conId,$row)){
throw new Exception('Error seeking row');
}
return $row;
}
// public 'getAffectedRows()' method
public function getAffectedRows(){
if(!$rows=mysql_affected_rows($this->mysql->conId)){
throw new Exception('Error counting affected rows');
}
return $rows;
}
}
try{
// connect to MySQL
$db=new MySQL(array('host'=>'host','user'=>'user','password'=>'pass','database'=>'database'));
$id=!$_GET['id']?1:$_GET['id'];
// run query
$result=$db->query("SELECT firstname,lastname,email,comments FROM users WHERE id='$id'");
// display user information
$row=$result->fetchRow();
if($result->countRows()==1){
echo '<h2>User Information</h2>';
echo '<p><strong>First Name: </strong>'.$row['firstname'].'</p>';
echo '<p><strong>Last Name: </strong>'.$row['lastname'].'</p>';
echo '<p><strong>Email: </strong>'.$row['email'].'</p>';
echo '<p><strong>Comments: </strong>'.$row['comments'].'</p>';
}
}
catch(Exception $e){
echo $e->getMessage();
exit();
}
?>
In addition to the source files listed above, below I included an illustrative image that shows how the details of a particular user are displayed on the same web page, instead of opening a new window:
Final thoughts
That's all for now. In this third installment of the series, you hopefully learned how to use click interceptions to extend the existing functionality of a small MySQL-driven web application.
Nevertheless, this educational journey hasn't finished yet, since in its last chapter, I'll show you how to utilize click interceptions to display the contents of different text files on a unique web page container.
Don't miss the next part!
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