################ CodeIgniter URLs ################ By default, URLs in CodeIgniter are designed to be search-engine and human friendly. Rather than using the standard "query string" approach to URLs that is synonymous with dynamic systems, CodeIgniter uses a **segment-based** approach:: example.com/news/article/my_article .. note:: Query string URLs can be optionally enabled, as described below. URI Segments ============ The segments in the URL, in following with the Model-View-Controller approach, usually represent:: example.com/class/function/ID #. The first segment represents the controller **class** that should be invoked. #. The second segment represents the class **function**, or method, that should be called. #. The third, and any additional segments, represent the ID and any variables that will be passed to the controller. The :doc:`URI Library <../libraries/uri>` and the :doc:`URL Helper <../helpers/url_helper>` contain functions that make it easy to work with your URI data. In addition, your URLs can be remapped using the :doc:`URI Routing <routing>` feature for more flexibility. Friendly URLs ============= As you might guess, since there's a straight relationship between URI segments and the controller/method pair that's being called, those two determining segments must represent a valid class and method name. You may however also use dashes in the class/method-representing segments, and they will automatically be translated to underscores in order to be valid routed segments. For example:: example.com/my-settings/change-password/ The above example will route to the ``My_settings`` controller and its method ``change_password()``. Removing the index.php file =========================== By default, the **index.php** file will be included in your URLs:: example.com/index.php/news/article/my_article If your Apache server has *mod_rewrite* enabled, you can easily remove this file by using a .htaccess file with some simple rules. Here is an example of such a file, using the "negative" method in which everything is redirected except the specified items: :: RewriteEngine On RewriteCond %{REQUEST_FILENAME} !-f RewriteCond %{REQUEST_FILENAME} !-d RewriteRule ^(.*)$ index.php/$1 [L] In the above example, any HTTP request other than those for existing directories and existing files is treated as a request for your index.php file. .. note:: These specific rules might not work for all server configurations. .. note:: Make sure to also exclude from the above rule any assets that you might need to be accessible from the outside world. Adding a URL Suffix =================== In your **config/config.php** file you can specify a suffix that will be added to all URLs generated by CodeIgniter. For example, if a URL is this:: example.com/index.php/products/view/shoes You can optionally add a suffix, like **.html,** making the page appear to be of a certain type:: example.com/index.php/products/view/shoes.html Enabling Query Strings ====================== In some cases you might prefer to use query strings URLs:: index.php?c=products&m=view&id=345 CodeIgniter optionally supports this capability, which can be enabled in your **application/config.php** file. If you open your config file you'll see these items:: $config['enable_query_strings'] = FALSE; $config['controller_trigger'] = 'c'; $config['function_trigger'] = 'm'; If you change "enable_query_strings" to TRUE this feature will become active. Your controllers and functions will then be accessible using the "trigger" words you've set to invoke your controllers and methods:: index.php?c=controller&m=method .. note:: If you are using query strings you will have to build your own URLs, rather than utilizing the URL helpers (and other helpers that generate URLs, like some of the form helpers) as these are designed to work with segment based URLs.