Migration from 2.x to 3.x

TinyAuth

TinyAuth has been moved to its own plugin.

Auth

As session is not static anymore Auth class has been refactored into component and helper (incl. trait) and can be used as AuthUser.

Geo

Behaviors Geocodable and Helper GoogleMapsV3 are now moved to a separate Geo plugin.

Utility

*Lib are now just * classes
Utility::getMimeType() is now Mime::detectMimeType()
$this->Time->isLeapYear() now doesnt take an argument anymore

Controller

Flash message functionality has been extracted into Flash component and Flash helper.
$this->Common->flashMessage() is now $this->Flash->message().
$this->Common->transientFlashMessage() is now $this->Flash->transientMessage().

Behavior

run/before config options for callback decisions have been unified to on and complete callback/event name, e.g. 'on' => 'beforeValidate'.

SluggedBehavior

Model names are now table names, and plural.
Slug field name option "slugField" is now "field", "multiSlug" has been removed for now as well as currencies.

PasswordableBehavior

You can/should now specify a "validator", it defaults to "default".

JsonableBehavior

No auto-detect anymore, fields need to be specified manually

Rss View

This has been moved to cakephp-feed plugin.