# Upgrading from 1.7.2 to 2.0.0

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

## Update Instructions

### Step 1: Update your CodeIgniter files

Replace all files and directories in your “system” folder except your application folder.

Note

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

### Step 2: Adjust get_dir_file_info() where necessary

Version 2.0.0 brings a non-backwards compatible change to get_dir_file_info() in the File Helper. Non-backwards compatible changes are extremely rare in CodeIgniter, but this one we feel was warranted due to how easy it was to create serious server performance issues. If you need recursiveness where you are using this helper function, change such instances, setting the second parameter, $top_level_only to FALSE:

    get_dir_file_info('/path/to/directory', FALSE);

### Step 3: Convert your Plugins to Helpers

2.0.0 gets rid of the “Plugin” system as their functionality was identical to Helpers, but non-extensible. You will need to rename your plugin files from filename_pi.php to filename_helper.php, move them to your helpers folder, and change all instances of:

    $this->load->plugin('foo');

to

    $this->load->helper('foo');

### Step 4: Update stored encrypted data

Note

If your application does not use the Encrypt library, does not store Encrypted data permanently, or is on an environment that does not support Mcrypt, you may skip this step.

The Encrypt library has had a number of improvements, some for encryption strength and some for performance, that has an unavoidable consequence of making it no longer possible to decode encrypted data produced by the original version of this library. To help with the transition, a new method has been added, encode_from_legacy() that will decode the data with the original algorithm and return a re-encoded string using the improved methods. This will enable you to easily replace stale encrypted data with fresh in your applications, either on the fly or en masse.

Please read how to use this method in the Encrypt library documentation.

### Step 5: Remove loading calls for the compatibility helper.

The compatibility helper has been removed from the CodeIgniter core. All methods in it should be natively available in supported PHP versions.

### Step 6: Update Class extension

All core classes are now prefixed with CI_. Update Models and Controllers to extend CI_Model and CI_Controller, respectively.

### Step 7: Update Parent Constructor calls

All native CodeIgniter classes now use the PHP 5 __construct() convention. Please update extended libraries to call parent::__construct().

### Step 8: Move any core extensions to application/core

Any extensions to core classes (e.g. MY_Controller.php) in your application/libraries folder must be moved to the new application/core folder.

### Step 9: Update your user guide

Please replace your local copy of the user guide with the new version, including the image files.

## Update Notes

Please refer to the 2.0.0 Change Log for full details, but here are some of the larger changes that are more likely to impact your code:

- Scaffolding has been removed.
- The CAPTCHA plugin in now a helper.
- The JavaScript calendar plugin was removed.
- The system/cache and system/logs directories are now in the application directory.
- The Validation class has been removed. Please see the Form Validation library
- “default” is now a reserved name.
- The xss_clean() function has moved to the Security Class.
- do_xss_clean() now returns FALSE if the uploaded file fails XSS checks.
- The Session Class requires now the use of an encryption key set in the config file.
- The following deprecated Active Record functions have been removed: `orwhere`, `orlike`, `groupby`, `orhaving`, `orderby`, `getwhere`.
- `_drop_database()` and `_create_database()` functions have been removed from the db utility drivers.
- The `dohash()` function of the Security helper has been renamed to `do_hash()` for naming consistency.

### The config folder

The following files have been changed:

- config.php
- database.php
- mimes.php
- routes.php
- user_agents.php

The following files have been added:

- foreign_chars.php
- profiler.php