Page 199 - Open Soource Technologies 304.indd

Unit 8: Objects

Notes
Figure 8.2: Object Introspection Output

Class

a
Inheritance
Parents
None
Children
b
Methods
Inherited methods arein italics:
first__function();
second_function();
Properties
$foo = cylvie
$har =23
$baz =17

8.7 Serialization

Serialize() returns a string containing a byte-stream representation of any value that can be
stored in PHP, unserialize() can use this string to recreate the original variable values. Using
serialize to save an object will save all variables in an object. The functions in an object will not
be saved, only the name of the class.
In order to be able to unserialize() an object, the class of that object needs to be defined. That
is, if you have an object $a of class A on page1.php and serialize this, you will get a string that
refers to class A and contains all values of variabled contained in $a. If you want to be able to
unserialize this on page2.php, recreating $a of class A, the definition of class A must be present
in page2.php. This can be done for example by storing the class definition of class A in an include
file and including this file in both page1.php and page2.php.

<?php// classa.inc:
class A {
var $one = 1;
function show_one() {
echo $this->one;} }// page1.php:
include(“classa.inc”);

$a = new A;
$s = serialize($a);
// store $s somewhere where page2.php can find it.
$fp = fopen(“store”, “w”);

LOVELY PROFESSIONAL UNIVERSITY 193