replacing the old HTML user guide with a Sphinx-managed user guide

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+################
+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 folder.
+
+Loading a Helper
+================
+
+Loading a helper file is quite simple using the following function::
+
+	$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 functions (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 function 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::
+
+	$this->load->helper( array('helper1', 'helper2', 'helper3') );
+
+Auto-loading Helpers
+====================
+
+If you find that you need a particular helper globally throughout your
+application, you can tell CodeIgniter to auto-load it during system
+initialization. This is done by opening the
+application/config/autoload.php file and adding the helper to the
+autoload array.
+
+Using a Helper
+==============
+
+Once you've loaded the Helper File containing the function you intend to
+use, you'll call it the way you would a standard PHP function.
+
+For example, to create a link using the anchor() function in one of your
+view files you would do this::
+
+	<?php echo anchor('blog/comments', 'Click Here');?>
+
+Where "Click Here" is the name of the link, and "blog/comments" is the
+URI to the controller/function you wish to link to.
+
+"Extending" Helpers
+===================
+
+To "extend" Helpers, create a file in your application/helpers/ folder
+with an identical name to the existing Helper, but prefixed with MY\_
+(this item is configurable. See below.).
+
+If all you need to do is add some functionality to an existing helper -
+perhaps add a function or two, or change how a particular helper
+function operates - then it's overkill to replace the entire helper with
+your version. In this case it's better to simply "extend" the Helper.
+The term "extend" is used loosely since Helper functions are procedural
+and discrete and cannot be extended in the traditional programmatic
+sense. Under the hood, this gives you the ability to add to the
+functions a Helper provides, or to modify how the native Helper
+functions operate.
+
+For example, to extend the native Array Helper you'll create a file
+named application/helpers/MY_array_helper.php, and add or override
+functions::
+
+	 // any_in_array() is not in the Array Helper, so it defines a new function function any_in_array($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.