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.
- -Helpers are intentionally kept very simple so that they can be used within your View Files with a minimal amount of code. -This is important if you intend to have designers or non-programmer will be working with your view files, since it keeps the code to a minimum. -
- -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 controller and views.
- -Loading a Helper
- -Loading a helper file is quite simple using the following function:
- -$this->load->helper('name');
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-Where name is the file name of the helper, without the .php file extension or the "helper" part.
- -For example, to load the URL Helper file, which is named url_helper.php, you would do this:
- -$this->load->helper('url');
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-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.
- -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:
- -<?=anchor('blog/comments', 'Click Here');?>
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-Where "Click Here" is the name of the link, and "blog/comments" is the URI to the controller/function you wish to link to.
- - -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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