Using objects in Ajax calls PHP files

Question

I have instantiated a class in my index.php file. But then I use jQuery Ajax to call some PHP files, but they can't use my object that I created in the index.php file.

How can I make it work? Because I don´t want to create new objects, because the one I created holds all the property values I want to use.

Answer 1

Use the session to save the object for the next page load.

// Create a new object
$object = new stdClass();
$object->value = 'something';
$object->other_value = 'something else';

// Start the session
session_start();

// Save the object in the user's session
$_SESSION['object'] = $object;

Then in the next page that loads from AJAX

// Start the session saved from last time
session_start();

// Get the object out
$object = $_SESSION['object'];

// Prints "something"
print $object->value;

By using the PHP sessions you can save data across many pages for a certain user. For example, maybe each user has a shopping cart object that contains a list of items they want to buy. Since you are storing that data in THAT USERS session only - each user can have their own shopping cart object that is saved on each page!

Answer 2

If you don't want to move your object that is in your index.php, have your ajax make a request to index.php but add some extra parameters (post/get) that let your index.php know to process it as an ajax request and not return your normal web page html output.

Answer 3

Another option if you dont want to use sessions is to serialize your object and send it through a $_POST value in your AJAX call. Not the most elegant way to do it, but a good alternative if you don't want to use sessions.

See Object Serialization in the documentation for more informations.

Answer 4

You have not provided code, but what I guess is that you need to make your instantiated object global for other scripts to see it, example:

$myobject = new myobject();

Now I want to use this object elsewhere, probably under some function or class, or any place where it is not getting recognized, so I will make this global with the global keyword and it will be available there as well:

global $myobject;

Once you have the object, you can put it into the session and then utilize it in the Ajax script file.

Answer 5

mm, you should store in session, $_SESSION["someobj"] = $myobj;, and ensure that when you call the Ajax PHP file this includes the class necessary files which defines the class of $myobj and any contained object in it.

Could you be more specific? I can try.

This is how I create an object then assign it to a session variable:

include(whateverfilethathastheclassorincludeit.php)
$theObject = new TheObjectClass();
//do something with the object or not
$_SESSION['myobject'] = $theObject;

This is how I access the object's members in my Ajax call PHP file:

include(whateverfilethathastheclassorincludeit.php)
$theObject = $_SESSION['myobject'];
//do something with the object

Answer 6

Based on most of the answers here, referring to storing the object in $_SESSION, is it more efficient to store only the individual properties that need to be accessed in AJAX as opposed to the whole object, or does it not matter?

E.g.

$_SESSION['object'] = $object;

vs

$_SESSION['property1'] = $object->property1;
$_SESSION['property2'] = $object->property2;

I know the OP is asking about accessing the entire object, but I guess my question pertains to if it's just a matter of only accessing certain properties of an object, and not needing to access methods of a class to alter the object once it's in AJAX.