PHP, JSON and JavaScript in Web2.0 Applications - Part 2

Go To Part 1 of PHP, JSON and JavaScript in Web2.0 Applications

We will now move on to the server side script GiveAd.php

PHP Script on the server should reply in JSON – enabling JavaScript to receive the output. Here is an example of PHP Script doing just that. GiveAd.php serves as the back end to ShowAd.html shown in Part 1 of PHP, JSON and JavaScript:


<?php
/**
* This is Ad serving file
* @desc 
* 
*/

//This is the whole magic - calling DebugBreak() will automatically start debugging session
DebugBreak();

$clientId = (isset($_GET["clientId"]) ? $_GET["clientId"] : ""); 
$callback = $_GET["callback"];
 
//DebugBreak();

$ad = null;
//select corresponding advertisement
 switch ($clientId) {
    case "really_cool_cars":
        $ad = ads_for_grownups();
        break;
    case "really_cool_toys":
        $ad = ads_for_kids();
        break;
    default:
        $ad = ads_for_everybody();
 }
 
 //encode output in JSON
 $output = json_encode($ad);
 
 //  send it back to the caller
 print ($callback."(".$output.");");
 
 
 
 //Grownups love sale and cars
 function  ads_for_grownups() {
 $value =  array ('Title'=>'Cheapest Used Cars!', 
                  'Ad_Body' => array ('Punch_line'=> 'On line super sale car store', 
                                            'URL'=>'www.supercheapcars.com'));
 return $value;
 }
 
 
 //Kids love Candy (at least we would like to think that)
 function  ads_for_kids() {
 $value = array('Ad' =>  array ('Title'=>'Best Candy store!'),
                'Ad_Body' => array ('Punch_line'=> 'On line Candy supermarket!', 'URL'=>'www.allthingscandy.com'));
 return $value;
 }
 
 //For now return grownups ad for everybody
 
 function  ads_for_everybody() {
 $value = ads_for_grownups();
 return $value;
 }
?>