strange behavior while including a class in php - php

Question

I'm experiencing a strange behavior with PHP. Basically I want to require a class within a PHP script. I know it is straight forward and I did it before but when I do so, it change the behavior of my jquery (1.8.3) ajax response. I'm running a wamp setup and my PHP version is 5.4.6.
Here is a sample as for my index.html
head (omitting the jquery js include)
<script>
$(document).ready(function(){
$('#submit').click(function(){
var action = $('#form').attr('action');
var form_data = {
fname: $('#fname').val(),
lname: $('#lname').val(),
phone: $('#phone').val(),
email: $('#email').val(),
is_ajax: 1
};
$.ajax({
type: $('#form').attr('method'),
url: action,
data: form_data,
success: function(response){
switch(response){
case 'ok':
var msg = 'data saved';
break;
case 'ko':
var msg = 'Oops something wrong happen';
break;
default:
var msg = 'misc:<br/>'+response;
break;
}
$('#message').html(msg);
}
});
return false;
});
});
</script>
body
<div id="message"></div>
<form id="form" action="handler.php" method="post">
<p>
<input type="text" name="fname" id="fname" placeholder="fname">
<input type="text" name="lname" id="lname" placeholder="lname">
</p>
<p>
<input type="text" name="phone" id="phone" placeholder="phone">
<input type="text" name="email" id="email" placeholder="email">
</p>
<input type="submit" name="submit" value="submit" id="submit">
</form>
And as for the handler.php file:
<?php
require('class/Container.php');
$filename = 'xml/memory.xml';
$is_ajax = $_REQUEST['is_ajax'];
if(isset($is_ajax) && $is_ajax){
$fname = $_REQUEST['fname'];
$lname = $_REQUEST['lname'];
$phone = $_REQUEST['phone'];
$email = $_REQUEST['email'];
$obj = new Container;
$obj->insertData('fname',$fname);
$obj->insertData('lname',$lname);
$obj->insertData('phone',$phone);
$obj->insertData('email',$email);
$tmp = $obj->give();
$result = $tmp['_obj'];
/*
Push data inside array
*/
$array = array();
foreach($result as $key => $value){
array_push($array,$key,$value);
}
$xml = simplexml_load_file($filename);
// check if there is any data in
if(count($xml->elements->data) == 0){
// if not, create the structure
$xml->elements->addChild('data','');
}
// proceed now that we do have the structure
if(count($xml->elements->data) == 1){
foreach($result as $key => $value){
$xml->elements->data->addChild($key,$value);
}
$xml->saveXML($filename);
echo 'ok';
}else{
echo 'ko';
}
}
?>
The Container class:
<?php
class Container{
private $_obj;
public function __construct(){
$this->_obj = array();
}
public function addData($data = array()){
if(!empty($data)){
$oldData = $this->_obj;
$data = array_merge($oldData,$data);
$this->_obj = $data;
}
}
public function removeData($key){
if(!empty($key)){
$oldData = $this->_obj;
unset($oldData[$key]);
$this->_obj = $oldData;
}
}
public function outputData(){
return $this->_obj;
}
public function give(){
return get_object_vars($this);
}
public function insertData($key,$value){
$this->_obj[$key] = $value;
}
}
?>
The strange thing is that my result always fall under the default switch statement and the ajax response fit both present statement. I noticed then if I just paste the Container class on the top of the handler.php file, everything works properly but it kind of defeat what I try to achieve.
I tried different way to include the Container class but it seem to be than the issue is specific to this current scenario.
I'm still learning PHP and my guess is that I'm missing something really basic. I also search on stackoverflow regarding the issue I'm experiencing as well as PHP.net, without success.
Regards,

Answer 1

My guess is that you have white space at the end of your class file, which is causing the output to be ' ok' instead of 'ok'. This can be the result of using certain applications to edit your files, or accidentally adding a space after the closing ?>. Try removing the closing ?> in your php class all together. This is not only allowed (php will automatically end processing at the end of the file anyways), but often encouraged in many style guides to prevent exactly the kind of thing that you are describing.
Another thing I usually do for this type of situation, is instead of returning a plain string, I return a json string, which jQuery will automatically turn into a javascript object for you. This would also prevent, or at least let you know right away that you are having the above type of problem.
so php would echo like this:
exit( json_encode( array( 'status' => 'ok' ) ) );
and jQuery would receive like this:
$.ajax({
type: $('#form').attr('method'),
url: action,
data: form_data,
dataType: 'json',
success: function(response){
switch(response.status){
case 'ok':
var msg = 'data saved';
break;
case 'ko':
var msg = 'Oops something wrong happen';
break;
default:
var msg = 'misc:<br/>'+response;
break;
}
$('#message').html(msg);
}
});
Note the added dataType parameter in the ajax call, as well as using response.status to check the status property that we created in PHP.
This also allows you to return more than one value in your response. You can build the object or array however you like on the PHP side, and you would basically receive the same as a javascript object on the javascript side.