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
