# Upgrading from 3.0.5 to 3.0.6

Before performing an update you should take your site offline by replacing the index.php file with a static one.

## Step 1: Update your CodeIgniter files

Replace all files and directories in your system/ directory.

注解

If you have any custom developed files in these directories, please make copies of them first.

## Step 2: Update your index.php file (optional)

We've made some tweaks to the index.php file, mostly related to proper usage of directory separators (i.e. use the `DIRECTORY_SEPARATOR` constant instead of a hard coded forward slash "/").

Nothing will break if you skip this step, but if you're running Windows or just want to be up to date with every change - we do recommend that you update your index.php file.

Tip: Just copy the ``ENVIRONMENT``, ``$system_path``, ``$application_folder`` and ``$view_folder`` declarations from the old file and put them into the new one, replacing the defaults.

## Step 3: Remove 'prep_for_form' usage (deprecation)

The Form Validation Library has a `prep_for_form()` method, which is/can also be used as a rule in `set_rules()` to automatically perform HTML encoding on input data.

Automatically encoding input (instead of output) data is a bad practice in the first place, and CodeIgniter and PHP itself offer other alternatives to this method anyway. For example, Form Helper functions will automatically perform HTML escaping when necessary.

Therefore, the prep_for_form method/rule is pretty much useless and is now deprecated and scheduled for removal in 3.1+.

注解

The method is still available, but you're strongly encouraged to remove its usage sooner rather than later.