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diff --git a/user_guide_src/source/general/helpers.rst b/user_guide_src/source/general/helpers.rst deleted file mode 100644 index d171aa8ed..000000000 --- a/user_guide_src/source/general/helpers.rst +++ /dev/null @@ -1,145 +0,0 @@ -################ -Helper Functions -################ - -Helpers, as the name suggests, help you with tasks. Each helper file is -simply a collection of functions in a particular category. There are **URL -Helpers**, that assist in creating links, there are Form Helpers that help -you create form elements, **Text Helpers** perform various text formatting -routines, **Cookie Helpers** set and read cookies, File Helpers help you -deal with files, etc. - -Unlike most other systems in CodeIgniter, Helpers are not written in an -Object Oriented format. They are simple, procedural functions. Each -helper function performs one specific task, with no dependence on other -functions. - -CodeIgniter does not load Helper Files by default, so the first step in -using a Helper is to load it. Once loaded, it becomes globally available -in your :doc:`controller <../general/controllers>` and -:doc:`views <../general/views>`. - -Helpers are typically stored in your **system/helpers**, or -**application/helpers directory**. CodeIgniter will look first in your -**application/helpers directory**. If the directory does not exist or the -specified helper is not located there CI will instead look in your -global *system/helpers/* directory. - -Loading a Helper -================ - -Loading a helper file is quite simple using the following method:: - - $this->load->helper('name'); - -Where **name** is the file name of the helper, without the .php file -extension or the "helper" part. - -For example, to load the **URL Helper** file, which is named -**url_helper.php**, you would do this:: - - $this->load->helper('url'); - -A helper can be loaded anywhere within your controller methods (or -even within your View files, although that's not a good practice), as -long as you load it before you use it. You can load your helpers in your -controller constructor so that they become available automatically in -any function, or you can load a helper in a specific function that needs -it. - -.. note:: The Helper loading method above does not return a value, so - don't try to assign it to a variable. Just use it as shown. - -Loading Multiple Helpers -======================== - -If you need to load more than one helper you can specify them in an -array, like this:: - - $this->load->helper( - array('helper1', 'helper2', 'helper3') - ); - -Auto-loading Helpers -==================== - -If you find that you need a particular helper globally throughout your -application, you can tell CodeIgniter to auto-load it during system -initialization. This is done by opening the **application/config/autoload.php** -file and adding the helper to the autoload array. - -Using a Helper -============== - -Once you've loaded the Helper File containing the function you intend to -use, you'll call it the way you would a standard PHP function. - -For example, to create a link using the ``anchor()`` function in one of -your view files you would do this:: - - <?php echo anchor('blog/comments', 'Click Here');?> - -Where "Click Here" is the name of the link, and "blog/comments" is the -URI to the controller/method you wish to link to. - -"Extending" Helpers -=================== - -To "extend" Helpers, create a file in your **application/helpers/** folder -with an identical name to the existing Helper, but prefixed with **MY\_** -(this item is configurable. See below.). - -If all you need to do is add some functionality to an existing helper - -perhaps add a function or two, or change how a particular helper -function operates - then it's overkill to replace the entire helper with -your version. In this case it's better to simply "extend" the Helper. - -.. note:: The term "extend" is used loosely since Helper functions are - procedural and discrete and cannot be extended in the traditional - programmatic sense. Under the hood, this gives you the ability to - add to or or to replace the functions a Helper provides. - -For example, to extend the native **Array Helper** you'll create a file -named **application/helpers/MY_array_helper.php**, and add or override -functions:: - - // any_in_array() is not in the Array Helper, so it defines a new function - function any_in_array($needle, $haystack) - { - $needle = is_array($needle) ? $needle : array($needle); - - foreach ($needle as $item) - { - if (in_array($item, $haystack)) - { - return TRUE; - } - } - - return FALSE; - } - - // random_element() is included in Array Helper, so it overrides the native function - function random_element($array) - { - shuffle($array); - return array_pop($array); - } - -Setting Your Own Prefix ------------------------ - -The filename prefix for "extending" Helpers is the same used to extend -libraries and core classes. To set your own prefix, open your -**application/config/config.php** file and look for this item:: - - $config['subclass_prefix'] = 'MY_'; - -Please note that all native CodeIgniter libraries are prefixed with **CI\_** -so DO NOT use that as your prefix. - -Now What? -========= - -In the Table of Contents you'll find a list of all the available Helper -Files. Browse each one to see what they do.
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