From b0dd10f8171945e0c1f3527dd1e9d18b043e01a7 Mon Sep 17 00:00:00 2001 From: admin Date: Fri, 25 Aug 2006 17:25:49 +0000 Subject: Initial Import --- user_guide/general/creating_libraries.html | 222 +++++++++++++++++++++++++++++ 1 file changed, 222 insertions(+) create mode 100644 user_guide/general/creating_libraries.html (limited to 'user_guide/general/creating_libraries.html') diff --git a/user_guide/general/creating_libraries.html b/user_guide/general/creating_libraries.html new file mode 100644 index 000000000..fa3416767 --- /dev/null +++ b/user_guide/general/creating_libraries.html @@ -0,0 +1,222 @@ + + + + +Code Igniter User Guide + + + + + + + + + + + + + + + + + + + + + + +
+ + + + + +

Code Igniter User Guide Version 1.4.0

+
+ + + + + + + + + +
+ + +
+ + + +
+ +

Creating Libraries

+ +

When we use the term "Libraries" we are normally referring to the classes that are located in the libraries +directory and described in the Class Reference of this user guide. In this case, however, we will instead describe how you can create your own libraries within +your application directory in order to maintain separation between your local resources and the global framework resources.

+ +

Storage

+ +

In order for your libraries to be stored in your application folder you will need to create two directories in which to store them:

+ + + + +

Anatomy of a Library

+ +

A class library consists of two components:

+ +
    +
  1. An init file.
    2. +
  2. A class file.
    3. +
+ +

The Init File

+ +

An init file a small initialization file corresponding to each of your classes. The purpose of this file is to +instantiate a particular class. Each init file must be named identically to your class file name, adding the "init_" prefix. For example, if your +class is named myclass.php your init file will be named:

+ +init_myclass.php + +

Within your init file you will place your initialization code. Here's an example of such code, using an imaginary class named Myclass:

+ + +<?php if (!defined('BASEPATH')) exit('No direct script access allowed');
+
+if ( ! class_exists('Myclass'))
+{
+     require_once(APPPATH.'libraries/Myclass'.EXT);
+}
+
+$obj =& get_instance();
+$obj->myclass = new Myclass();
+$obj->ci_is_loaded[] = 'myclass';
+
+?> + +

The Class File

+ +

Your class file itself will be placed inside your libraries directory:

+ +application/libraries/myclass.php + +

The class will have this basic prototype:

+ +<?php if (!defined('BASEPATH')) exit('No direct script access allowed');
+
+class Myclass {
+
+}
+?> + + +

Naming Conventions

+ + + + +

Using Your Class

+ +

From within any of your Controller classes you can initialize your class using the standard:

+ +$this->load->library('myclass'); + +

Once loaded you can access your class using:

+ +$this->myclass->function(); + +

Note: In your init file you can define the object variable name.

+ + +

Passing Parameters Your Class

+ +

In the library loading function you can pass data via the second parameter and it will be available to your initialization file:

+ + +$params = array('type' => 'large', 'color' => 'red');
+
+$this->load->library('myclass', $params); + +

Parameters will be accessible using a variable called $params. By default this variable is set to FALSE.

+ + +

Utilizing Code Igniter Resources within Your Library

+ + +

To access Code Igniter's native resources within your library use the get_instance() function. +This function returns the Code Igniter super object.

+ +

Normally, to call any of the available Code Igniter functions requires you to use the $this construct:

+ + +$this->load->helper('url');
+$this->load->library('session');
+$this->config->item('base_url');
+etc. + + +

$this, however, only works directly within your controllers, your models, or your views. +If you would like to use Code Igniter's classes from within your own custom classes you can do so as follows:

+ + +

First, assign the Code Igniter object to a variable:

+ +$obj =& get_instance(); + +

Once you've assigned the object to a variable, you'll use that variable instead of $this:

+ + +$obj =& get_instance();

+$obj->load->helper('url');
+$obj->load->library('session');
+$obj->config->item('base_url');
+etc. + + +

Note: You'll notice that the above get_instance() function is being passed by reference: +

+$obj =& get_instance(); +

+This is very important. Assigning by reference allows you to use the original Code Igniter object rather than creating a copy of it.

+ + + + + + + +
+ + + + + + + \ No newline at end of file -- cgit v1.2.3-24-g4f1b