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1 files changed, 297 insertions, 297 deletions
diff --git a/user_guide/general/creating_libraries.html b/user_guide/general/creating_libraries.html index 15dfcec1e..beac1959f 100644 --- a/user_guide/general/creating_libraries.html +++ b/user_guide/general/creating_libraries.html @@ -1,298 +1,298 @@ -<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
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-<td><h1>CodeIgniter User Guide Version 1.7</h1></td>
-<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td>
-</tr>
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-<a href="http://codeigniter.com/">CodeIgniter Home</a> ›
-<a href="../index.html">User Guide Home</a> ›
-Creating Libraries
-</td>
-<td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="codeigniter.com/user_guide/" />Search User Guide <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" /> <input type="submit" class="submit" name="sa" value="Go" /></form></td>
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-
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-<!-- START CONTENT -->
-<div id="content">
-
-<h1>Creating Libraries</h1>
-
-<p>When we use the term "Libraries" we are normally referring to the classes that are located in the <kbd>libraries</kbd>
-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 <dfn>application/libraries</dfn> directory in order to maintain separation between your local resources
-and the global framework resources.</p>
-
-<p>As an added bonus, CodeIgniter permits your libraries to <kbd>extend</kbd> native classes if you simply need to add some functionality
-to an existing library. Or you can even replace native libraries just by placing identically named versions in your <dfn>application/libraries</dfn> folder.</p>
-
-<p>In summary:</p>
-
-<ul>
-<li>You can create entirely new libraries.</li>
-<li>You can extend native libraries.</li>
-<li>You can replace native libraries.</li>
-</ul>
-
-<p>The page below explains these three concepts in detail.</p>
-
-<p class="important"><strong>Note:</strong> The Database classes can not be extended or replaced with your own classes,
-nor can the Loader class in PHP 4. All other classes are able to be replaced/extended.</p>
-
-
-<h2>Storage</h2>
-
-<p>Your library classes should be placed within your <dfn>application/libraries</dfn> folder, as this is where CodeIgniter will look for them when
-they are initialized.</p>
-
-
-<h2>Naming Conventions</h2>
-
-<ul>
-<li>File names must be capitalized. For example: <dfn>Myclass.php</dfn></li>
-<li>Class declarations must be capitalized. For example: <kbd>class Myclass</kbd></li>
-<li>Class names and file names must match.</li>
-</ul>
-
-
-<h2>The Class File</h2>
-
-<p>Classes should have this basic prototype (Note: We are using the name <kbd>Someclass</kbd> purely as an example):</p>
-
-<code><?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');
-<br /><br />
-class Someclass {<br />
-<br />
- function some_function()<br />
- {<br />
- }<br />
-}<br /><br />
-?></code>
-
-
-<h2>Using Your Class</h2>
-
-<p>From within any of your <a href="controllers.html">Controller</a> functions you can initialize your class using the standard:</p>
-
-<code>$this->load->library('<kbd>someclass</kbd>');</code>
-
-<p>Where <em>someclass</em> is the file name, without the ".php" file extension. You can submit the file name capitalized or lower case.
-CodeIgniter doesn't care.</p>
-
-<p>Once loaded you can access your class using the <kbd>lower case</kbd> version:</p>
-
-<code>$this-><kbd>someclass</kbd>->some_function(); // Object instances will always be lower case
-</code>
-
-
-
-<h2>Passing Parameters When Initializing Your Class</h2>
-
-<p>In the library loading function you can dynamically pass data via the second parameter and it will be passed to your class
-constructor:</p>
-
-<code>
-$params = array('type' => 'large', 'color' => 'red');<br />
-<br />
-$this->load->library('Someclass', <kbd>$params</kbd>);</code>
-
-<p>If you use this feature you must set up your class constructor to expect data:</p>
-
-<code><?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');<br />
-<br />
-class Someclass {<br />
-<br />
- function Someclass($params)<br />
- {<br />
- // Do something with $params<br />
- }<br />
-}<br /><br />
-?></code>
-
-<p class="important">You can also pass parameters stored in a config file. Simply create a config file named identically to the class <kbd>file name</kbd>
-and store it in your <dfn>application/config/</dfn> folder. Note that if you dynamically pass parameters as described above,
-the config file option will not be available.</p>
-
-
-
-
-
-
-
-<h2>Utilizing CodeIgniter Resources within Your Library</h2>
-
-
-<p>To access CodeIgniter's native resources within your library use the <kbd>get_instance()</kbd> function.
-This function returns the CodeIgniter super object.</p>
-
-<p>Normally from within your controller functions you will call any of the available CodeIgniter functions using the <kbd>$this</kbd> construct:</p>
-
-<code>
-<strong>$this</strong>->load->helper('url');<br />
-<strong>$this</strong>->load->library('session');<br />
-<strong>$this</strong>->config->item('base_url');<br />
-etc.
-</code>
-
-<p><kbd>$this</kbd>, however, only works directly within your controllers, your models, or your views.
-If you would like to use CodeIgniter's classes from within your own custom classes you can do so as follows:</p>
-
-
-<p>First, assign the CodeIgniter object to a variable:</p>
-
-<code>$CI =& get_instance();</code>
-
-<p>Once you've assigned the object to a variable, you'll use that variable <em>instead</em> of <kbd>$this</kbd>:</p>
-
-<code>
-$CI =& get_instance();<br />
-<br />
-$CI->load->helper('url');<br />
-$CI->load->library('session');<br />
-$CI->config->item('base_url');<br />
-etc.
-</code>
-
-<p class="important"><strong>Note:</strong> You'll notice that the above get_instance() function is being passed by reference:
-<br /><br />
-<var>$CI =& get_instance();</var>
-<br />
-<br />
-<kbd>This is very important.</kbd> Assigning by reference allows you to use the original CodeIgniter object rather than creating a copy of it.
-<br /><br />
-<kbd>Also, please note:</kbd> If you are running PHP 4 it's usually best to avoid calling <dfn>get_instance()</dfn>
-from within your class constructors. PHP 4 has trouble referencing the CI super object within application constructors
-since objects do not exist until the class is fully instantiated.</p>
-
-
-<h2>Replacing Native Libraries with Your Versions</h2>
-
-<p>Simply by naming your class files identically to a native library will cause CodeIgniter to use it instead of the native one. To use this
-feature you must name the file and the class declaration exactly the same as the native library. For example, to replace the native <kbd>Email</kbd> library
-you'll create a file named <dfn>application/libraries/Email.php</dfn>, and declare your class with:</p>
-
-<code>
-class CI_Email {<br /><br />
-
-}</code>
-
-<p>Note that most native classes are prefixed with <kbd>CI_</kbd>.</p>
-
-<p>To load your library you'll see the standard loading function:</p>
-
-<code>$this->load->library('<kbd>email</kbd>');</code>
-
-<p class="important"><strong>Note:</strong> At this time the Database classes can not be replaced with your own versions.</p>
-
-
-<h2>Extending Native Libraries</h2>
-
-<p>If all you need to do is add some functionality to an existing library - perhaps add a function or two - then
-it's overkill to replace the entire library with your version. In this case it's better to simply extend the class.
-Extending a class is nearly identical to replacing a class with a couple exceptions:</p>
-
-<ul>
-<li>The class declaration must extend the parent class.</li>
-<li>Your new class name and filename must be prefixed with <kbd>MY_</kbd> (this item is configurable. See below.).</li>
-</ul>
-
-<p>For example, to extend the native <kbd>Email</kbd> class you'll create a file named <dfn>application/libraries/</dfn><kbd>MY_Email.php</kbd>, and declare your class with:</p>
-
-<code>
-class MY_Email extends CI_Email {<br /><br />
-
-}</code>
-
-<p>Note: If you need to use a constructor in your class make sure you extend the parent constructor:</p>
-
-
-<code>
-class MY_Email extends CI_Email {<br />
-<br />
- function My_Email()<br />
- {<br />
- parent::CI_Email();<br />
- }<br />
-}</code>
-
-
-<h3>Loading Your Sub-class</h3>
-
-<p>To load your sub-class you'll use the standard syntax normally used. DO NOT include your prefix. For example,
-to load the example above, which extends the Email class, you will use:</p>
-
-<code>$this->load->library('<kbd>email</kbd>');</code>
-
-<p>Once loaded you will use the class variable as you normally would for the class you are extending. In the case of
-the email class all calls will use:</p>
-
-
-<code>$this-><kbd>email</kbd>->some_function();</code>
-
-
-<h3>Setting Your Own Prefix</h3>
-
-<p>To set your own sub-class prefix, open your <dfn>application/config/config.php</dfn> file and look for this item:</p>
-
-<code>$config['subclass_prefix'] = 'MY_';</code>
-
-<p>Please note that all native CodeIgniter libraries are prefixed with <kbd>CI_</kbd> so DO NOT use that as your prefix.</p>
-
-
-
-</div>
-<!-- END CONTENT -->
-
-
-<div id="footer">
-<p>
-Previous Topic: <a href="libraries.html">Using CodeIgniter Libraries</a>
- ·
-<a href="#top">Top of Page</a> ·
-<a href="../index.html">User Guide Home</a> ·
-Next Topic: <a href="core_classes.html">Creating Core System Classes</a>
-</p>
-<p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2006-2008 · <a href="http://ellislab.com/">Ellislab, Inc.</a></p>
-</div>
-
-</body>
+<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd"> +<html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en"> +<head> + +<meta http-equiv="Content-Type" content="text/html; charset=utf-8" /> +<title>Creating Libraries : CodeIgniter User Guide</title> + +<style type='text/css' media='all'>@import url('../userguide.css');</style> +<link rel='stylesheet' type='text/css' media='all' href='../userguide.css' /> + +<script type="text/javascript" src="../nav/nav.js"></script> +<script type="text/javascript" src="../nav/prototype.lite.js"></script> +<script type="text/javascript" src="../nav/moo.fx.js"></script> +<script type="text/javascript" src="../nav/user_guide_menu.js"></script> + +<meta http-equiv='expires' content='-1' /> +<meta http-equiv= 'pragma' content='no-cache' /> +<meta name='robots' content='all' /> +<meta name='author' content='ExpressionEngine Dev Team' /> +<meta name='description' content='CodeIgniter User Guide' /> + +</head> +<body> + +<!-- START NAVIGATION --> +<div id="nav"><div id="nav_inner"><script type="text/javascript">create_menu('../');</script></div></div> +<div id="nav2"><a name="top"></a><a href="javascript:void(0);" onclick="myHeight.toggle();"><img src="../images/nav_toggle_darker.jpg" width="154" height="43" border="0" title="Toggle Table of Contents" alt="Toggle Table of Contents" /></a></div> +<div id="masthead"> +<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> +<tr> +<td><h1>CodeIgniter User Guide Version 1.7</h1></td> +<td id="breadcrumb_right"><a href="../toc.html">Table of Contents Page</a></td> +</tr> +</table> +</div> +<!-- END NAVIGATION --> + + +<!-- START BREADCRUMB --> +<table cellpadding="0" cellspacing="0" border="0" style="width:100%"> +<tr> +<td id="breadcrumb"> +<a href="http://codeigniter.com/">CodeIgniter Home</a> › +<a href="../index.html">User Guide Home</a> › +Creating Libraries +</td> +<td id="searchbox"><form method="get" action="http://www.google.com/search"><input type="hidden" name="as_sitesearch" id="as_sitesearch" value="codeigniter.com/user_guide/" />Search User Guide <input type="text" class="input" style="width:200px;" name="q" id="q" size="31" maxlength="255" value="" /> <input type="submit" class="submit" name="sa" value="Go" /></form></td> +</tr> +</table> +<!-- END BREADCRUMB --> + +<br clear="all" /> + + +<!-- START CONTENT --> +<div id="content"> + +<h1>Creating Libraries</h1> + +<p>When we use the term "Libraries" we are normally referring to the classes that are located in the <kbd>libraries</kbd> +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 <dfn>application/libraries</dfn> directory in order to maintain separation between your local resources +and the global framework resources.</p> + +<p>As an added bonus, CodeIgniter permits your libraries to <kbd>extend</kbd> native classes if you simply need to add some functionality +to an existing library. Or you can even replace native libraries just by placing identically named versions in your <dfn>application/libraries</dfn> folder.</p> + +<p>In summary:</p> + +<ul> +<li>You can create entirely new libraries.</li> +<li>You can extend native libraries.</li> +<li>You can replace native libraries.</li> +</ul> + +<p>The page below explains these three concepts in detail.</p> + +<p class="important"><strong>Note:</strong> The Database classes can not be extended or replaced with your own classes, +nor can the Loader class in PHP 4. All other classes are able to be replaced/extended.</p> + + +<h2>Storage</h2> + +<p>Your library classes should be placed within your <dfn>application/libraries</dfn> folder, as this is where CodeIgniter will look for them when +they are initialized.</p> + + +<h2>Naming Conventions</h2> + +<ul> +<li>File names must be capitalized. For example: <dfn>Myclass.php</dfn></li> +<li>Class declarations must be capitalized. For example: <kbd>class Myclass</kbd></li> +<li>Class names and file names must match.</li> +</ul> + + +<h2>The Class File</h2> + +<p>Classes should have this basic prototype (Note: We are using the name <kbd>Someclass</kbd> purely as an example):</p> + +<code><?php if ( ! defined('BASEPATH')) exit('No direct script access allowed'); +<br /><br /> +class Someclass {<br /> +<br /> + function some_function()<br /> + {<br /> + }<br /> +}<br /><br /> +?></code> + + +<h2>Using Your Class</h2> + +<p>From within any of your <a href="controllers.html">Controller</a> functions you can initialize your class using the standard:</p> + +<code>$this->load->library('<kbd>someclass</kbd>');</code> + +<p>Where <em>someclass</em> is the file name, without the ".php" file extension. You can submit the file name capitalized or lower case. +CodeIgniter doesn't care.</p> + +<p>Once loaded you can access your class using the <kbd>lower case</kbd> version:</p> + +<code>$this-><kbd>someclass</kbd>->some_function(); // Object instances will always be lower case +</code> + + + +<h2>Passing Parameters When Initializing Your Class</h2> + +<p>In the library loading function you can dynamically pass data via the second parameter and it will be passed to your class +constructor:</p> + +<code> +$params = array('type' => 'large', 'color' => 'red');<br /> +<br /> +$this->load->library('Someclass', <kbd>$params</kbd>);</code> + +<p>If you use this feature you must set up your class constructor to expect data:</p> + +<code><?php if ( ! defined('BASEPATH')) exit('No direct script access allowed');<br /> +<br /> +class Someclass {<br /> +<br /> + function Someclass($params)<br /> + {<br /> + // Do something with $params<br /> + }<br /> +}<br /><br /> +?></code> + +<p class="important">You can also pass parameters stored in a config file. Simply create a config file named identically to the class <kbd>file name</kbd> +and store it in your <dfn>application/config/</dfn> folder. Note that if you dynamically pass parameters as described above, +the config file option will not be available.</p> + + + + + + + +<h2>Utilizing CodeIgniter Resources within Your Library</h2> + + +<p>To access CodeIgniter's native resources within your library use the <kbd>get_instance()</kbd> function. +This function returns the CodeIgniter super object.</p> + +<p>Normally from within your controller functions you will call any of the available CodeIgniter functions using the <kbd>$this</kbd> construct:</p> + +<code> +<strong>$this</strong>->load->helper('url');<br /> +<strong>$this</strong>->load->library('session');<br /> +<strong>$this</strong>->config->item('base_url');<br /> +etc. +</code> + +<p><kbd>$this</kbd>, however, only works directly within your controllers, your models, or your views. +If you would like to use CodeIgniter's classes from within your own custom classes you can do so as follows:</p> + + +<p>First, assign the CodeIgniter object to a variable:</p> + +<code>$CI =& get_instance();</code> + +<p>Once you've assigned the object to a variable, you'll use that variable <em>instead</em> of <kbd>$this</kbd>:</p> + +<code> +$CI =& get_instance();<br /> +<br /> +$CI->load->helper('url');<br /> +$CI->load->library('session');<br /> +$CI->config->item('base_url');<br /> +etc. +</code> + +<p class="important"><strong>Note:</strong> You'll notice that the above get_instance() function is being passed by reference: +<br /><br /> +<var>$CI =& get_instance();</var> +<br /> +<br /> +<kbd>This is very important.</kbd> Assigning by reference allows you to use the original CodeIgniter object rather than creating a copy of it. +<br /><br /> +<kbd>Also, please note:</kbd> If you are running PHP 4 it's usually best to avoid calling <dfn>get_instance()</dfn> +from within your class constructors. PHP 4 has trouble referencing the CI super object within application constructors +since objects do not exist until the class is fully instantiated.</p> + + +<h2>Replacing Native Libraries with Your Versions</h2> + +<p>Simply by naming your class files identically to a native library will cause CodeIgniter to use it instead of the native one. To use this +feature you must name the file and the class declaration exactly the same as the native library. For example, to replace the native <kbd>Email</kbd> library +you'll create a file named <dfn>application/libraries/Email.php</dfn>, and declare your class with:</p> + +<code> +class CI_Email {<br /><br /> + +}</code> + +<p>Note that most native classes are prefixed with <kbd>CI_</kbd>.</p> + +<p>To load your library you'll see the standard loading function:</p> + +<code>$this->load->library('<kbd>email</kbd>');</code> + +<p class="important"><strong>Note:</strong> At this time the Database classes can not be replaced with your own versions.</p> + + +<h2>Extending Native Libraries</h2> + +<p>If all you need to do is add some functionality to an existing library - perhaps add a function or two - then +it's overkill to replace the entire library with your version. In this case it's better to simply extend the class. +Extending a class is nearly identical to replacing a class with a couple exceptions:</p> + +<ul> +<li>The class declaration must extend the parent class.</li> +<li>Your new class name and filename must be prefixed with <kbd>MY_</kbd> (this item is configurable. See below.).</li> +</ul> + +<p>For example, to extend the native <kbd>Email</kbd> class you'll create a file named <dfn>application/libraries/</dfn><kbd>MY_Email.php</kbd>, and declare your class with:</p> + +<code> +class MY_Email extends CI_Email {<br /><br /> + +}</code> + +<p>Note: If you need to use a constructor in your class make sure you extend the parent constructor:</p> + + +<code> +class MY_Email extends CI_Email {<br /> +<br /> + function My_Email()<br /> + {<br /> + parent::CI_Email();<br /> + }<br /> +}</code> + + +<h3>Loading Your Sub-class</h3> + +<p>To load your sub-class you'll use the standard syntax normally used. DO NOT include your prefix. For example, +to load the example above, which extends the Email class, you will use:</p> + +<code>$this->load->library('<kbd>email</kbd>');</code> + +<p>Once loaded you will use the class variable as you normally would for the class you are extending. In the case of +the email class all calls will use:</p> + + +<code>$this-><kbd>email</kbd>->some_function();</code> + + +<h3>Setting Your Own Prefix</h3> + +<p>To set your own sub-class prefix, open your <dfn>application/config/config.php</dfn> file and look for this item:</p> + +<code>$config['subclass_prefix'] = 'MY_';</code> + +<p>Please note that all native CodeIgniter libraries are prefixed with <kbd>CI_</kbd> so DO NOT use that as your prefix.</p> + + + +</div> +<!-- END CONTENT --> + + +<div id="footer"> +<p> +Previous Topic: <a href="libraries.html">Using CodeIgniter Libraries</a> + · +<a href="#top">Top of Page</a> · +<a href="../index.html">User Guide Home</a> · +Next Topic: <a href="core_classes.html">Creating Core System Classes</a> +</p> +<p><a href="http://codeigniter.com">CodeIgniter</a> · Copyright © 2006-2008 · <a href="http://ellislab.com/">Ellislab, Inc.</a></p> +</div> + +</body> </html>
\ No newline at end of file |