Page Contents
- Table Objects
- Basic Usage
- Lifecycle Callbacks
- Behaviors
- Configuring Connections
- Using the TableLocator
Table objects provide access to the collection of entities stored in a specific table. Each table in your application should have an associated Table class which is used to interact with a given table. If you do not need to customize the behavior of a given table CakePHP will generate a Table instance for you to use.
Before trying to use Table objects and the ORM, you should ensure that you have configured your database connection.
To get started, create a Table class. These classes live in src/Model/Table. Tables are a type model collection specific to relational databases, and the main interface to your database in CakePHP’s ORM. The most basic table class would look like:
// src/Model/Table/ArticlesTable.php
namespace App\Model\Table;
use Cake\ORM\Table;
class ArticlesTable extends Table
{
}
Note that we did not tell the ORM which table to use for our class. By
convention table objects will use a table that matches the lower cased and
underscored version of the class name. In the above example the articles
table will be used. If our table class was named BlogPosts
your table should
be named blog_posts
. You can specify the table to use by using the setTable()
method:
namespace App\Model\Table;
use Cake\ORM\Table;
class ArticlesTable extends Table
{
public function initialize(array $config)
{
$this->setTable('my_table');
// Prior to 3.4.0
$this->table('my_table');
}
}
No inflection conventions will be applied when specifying a table. By convention
the ORM also expects each table to have a primary key with the name of id
.
If you need to modify this you can use the setPrimaryKey()
method:
namespace App\Model\Table;
use Cake\ORM\Table;
class ArticlesTable extends Table
{
public function initialize(array $config)
{
$this->setPrimaryKey('my_id');
// Prior to 3.4.0
$this->primaryKey('my_id');
}
}
By default table objects use an entity class based on naming conventions. For
example if your table class is called ArticlesTable
the entity would be
Article
. If the table class was PurchaseOrdersTable
the entity would be
PurchaseOrder
. If however, you want to use an entity that doesn’t follow the
conventions you can use the setEntityClass()
method to change things up:
class PurchaseOrdersTable extends Table
{
public function initialize(array $config)
{
$this->setEntityClass('App\Model\Entity\PO');
// Prior to 3.4.0
$this->entityClass('App\Model\Entity\PO');
}
}
As seen in the examples above Table objects have an initialize()
method
which is called at the end of the constructor. It is recommended that you use
this method to do initialization logic instead of overriding the constructor.
Before you can query a table, you’ll need to get an instance of the table. You
can do this by using the TableLocator
class:
// In a controller or table method.
use Cake\ORM\TableRegistry;
// Prior to 3.6 use TableRegistry::get('Articles')
$articles = TableRegistry::getTableLocator()->get('Articles');
TableLocator
provides the various dependencies for constructing
a table, and maintains a registry of all the constructed table instances making
it easier to build relations and configure the ORM. See
Using the TableLocator for more information.
If your table class is in a plugin, be sure to use the correct name for your table class. Failing to do so can result in validation rules, or callbacks not being triggered as a default class is used instead of your actual class. To correctly load plugin table classes use the following:
// Plugin table
// Prior to 3.6 use TableRegistry::get('PluginName.Articles')
$articlesTable = TableRegistry::getTableLocator()->get('PluginName.Articles');
// Vendor prefixed plugin table
// Prior to 3.6 use TableRegistry::get('VendorName/PluginName.Articles')
$articlesTable = TableRegistry::getTableLocator()->get('VendorName/PluginName.Articles');
Deprecated since version 3.6.0: The static methods on TableRegistry
have been replaced by
TableLocator
. You can get the TableLocator from TableRegistry using
TableRegistry::getTableLocator()
.
As you have seen above table objects trigger a number of events. Events are useful if you want to hook into the ORM and add logic in without subclassing or overriding methods. Event listeners can be defined in table or behavior classes. You can also use a table’s event manager to bind listeners in.
When using callback methods behaviors attached in the
initialize()
method will have their listeners fired before the table
callback methods are triggered. This follows the same sequencing as controllers
& components.
To add an event listener to a Table class or Behavior simply implement the method signatures as described below. See the Events System for more detail on how to use the events subsystem.
Model.initialize
Model.beforeMarshal
Model.beforeFind
Model.buildValidator
Model.buildRules
Model.beforeRules
Model.afterRules
Model.beforeSave
Model.afterSave
Model.afterSaveCommit
Model.beforeDelete
Model.afterDelete
Model.afterDeleteCommit
The Model.initialize
event is fired after the constructor and initialize
methods are called. The Table
classes do not listen to this event by
default, and instead use the initialize
hook method.
To respond to the Model.initialize
event you can create a listener class
which implements EventListenerInterface
:
use Cake\Event\EventListenerInterface;
class ModelInitializeListener implements EventListenerInterface
{
public function implementedEvents()
{
return array(
'Model.initialize' => 'initializeEvent',
);
}
public function initializeEvent($event)
{
$table = $event->getSubject();
// do something here
}
}
and attach the listener to the EventManager
as below:
use Cake\Event\EventManager;
$listener = new ModelInitializeListener();
EventManager::instance()->on($listener);
This will call the initializeEvent
when any Table
class is constructed.
The Model.beforeMarshal
event is fired before request data is converted
into entities. See the Modifying Request Data Before Building Entities documentation for more information.
The Model.beforeFind
event is fired before each find operation. By stopping
the event and supplying a return value you can bypass the find operation
entirely. Any changes done to the $query instance will be retained for the rest
of the find. The $primary
parameter indicates whether or not this is the root
query, or an associated query. All associations participating in a query will
have a Model.beforeFind
event triggered. For associations that use joins,
a dummy query will be provided. In your event listener you can set additional
fields, conditions, joins or result formatters. These options/features will be
copied onto the root query.
You might use this callback to restrict find operations based on a user’s role, or make caching decisions based on the current load.
In previous versions of CakePHP there was an afterFind
callback, this has
been replaced with the Modifying Results with Map/Reduce features and entity constructors.
The Model.buildValidator
event is fired when $name
validator is created.
Behaviors, can use this hook to add in validation methods.
The Model.buildRules
event is fired after a rules instance has been
created and after the table’s buildRules()
method has been called.
The Model.beforeRules
event is fired before an entity has had rules applied. By
stopping this event, you can halt the rules checking and set the result
of applying rules.
The Model.afterRules
event is fired after an entity has rules applied. By
stopping this event, you can return the final value of the rules checking
operation.
The Model.beforeSave
event is fired before each entity is saved. Stopping
this event will abort the save operation. When the event is stopped the result
of the event will be returned.
The Model.afterSave
event is fired after an entity is saved.
The Model.afterSaveCommit
event is fired after the transaction in which the
save operation is wrapped has been committed. It’s also triggered for non atomic
saves where database operations are implicitly committed. The event is triggered
only for the primary table on which save()
is directly called. The event is
not triggered if a transaction is started before calling save.
The Model.beforeDelete
event is fired before an entity is deleted. By
stopping this event you will abort the delete operation. When the event is stopped the result
of the event will be returned.
The Model.afterDelete
event is fired after an entity has been deleted.
The Model.afterDeleteCommit
event is fired after the transaction in which the
delete operation is wrapped has been is committed. It’s also triggered for non
atomic deletes where database operations are implicitly committed. The event is
triggered only for the primary table on which delete()
is directly called.
The event is not triggered if a transaction is started before calling delete.
To prevent the save from continuing, simply stop event propagation in your callback:
public function beforeSave(Event $event, EntityInterface $entity, ArrayObject $options)
{
if (...) {
$event->stopPropagation();
$event->setResult(false);
return;
}
...
}
Alternatively, you can return false from the callback. This has the same effect as stopping event propagation.
When using events on your tables and behaviors be aware of the priority and the order listeners are attached. Behavior events are attached before Table events are. With the default priorities this means that Behavior callbacks are triggered before the Table event with the same name.
As an example, if your Table is using TreeBehavior
the
TreeBehavior::beforeDelete()
method will be called before your table’s
beforeDelete()
method, and you will not be able to work wth the child nodes
of the record being deleted in your Table’s method.
You can manage event priorities in one of a few ways:
Change the priority
of a Behavior’s listeners using the priority
option. This will modify the priority of all callback methods in the
Behavior:
// In a Table initialize() method
$this->addBehavior('Tree', [
// Default value is 10 and listeners are dispatched from the
// lowest to highest priority.
'priority' => 2,
]);
Modify the priority
in your Table
class by using the
Model.implementedEvents()
method. This allows you to assign a different
priority per callback-function:
// In a Table class.
public function implementedEvents()
{
$events = parent::implementedEvents();
$events['Model.beforeDelete'] = [
'callable' => 'beforeDelete',
'priority' => 3
];
return $events;
}
Behaviors provide an easy way to create horizontally re-usable pieces of logic related to table classes. You may be wondering why behaviors are regular classes and not traits. The primary reason for this is event listeners. While traits would allow for re-usable pieces of logic, they would complicate binding events.
To add a behavior to your table you can call the addBehavior()
method.
Generally the best place to do this is in the initialize()
method:
namespace App\Model\Table;
use Cake\ORM\Table;
class ArticlesTable extends Table
{
public function initialize(array $config)
{
$this->addBehavior('Timestamp');
}
}
As with associations, you can use plugin syntax and provide additional configuration options:
namespace App\Model\Table;
use Cake\ORM\Table;
class ArticlesTable extends Table
{
public function initialize(array $config)
{
$this->addBehavior('Timestamp', [
'events' => [
'Model.beforeSave' => [
'created_at' => 'new',
'modified_at' => 'always'
]
]
]);
}
}
You can find out more about behaviors, including the behaviors provided by CakePHP in the chapter on Behaviors.
By default all table instances use the default
database connection. If your
application uses multiple database connections you will want to configure which
tables use which connections. This is the defaultConnectionName()
method:
namespace App\Model\Table;
use Cake\ORM\Table;
class ArticlesTable extends Table
{
public static function defaultConnectionName() {
return 'replica_db';
}
}
Note
The defaultConnectionName()
method must be static.
As we’ve seen earlier, the TableRegistry class provides an easy way to use factory/registry for accessing your applications table instances. It provides a few other useful features as well.
When loading tables from the registry you can customize their dependencies, or
use mock objects by providing an $options
array:
// Prior to 3.6 use TableRegistry::get()
$articles = TableRegistry::getTableLocator()->get('Articles', [
'className' => 'App\Custom\ArticlesTable',
'table' => 'my_articles',
'connection' => $connectionObject,
'schema' => $schemaObject,
'entityClass' => 'Custom\EntityClass',
'eventManager' => $eventManager,
'behaviors' => $behaviorRegistry
]);
Pay attention to the connection and schema configuration settings, they aren’t
string values but objects. The connection will take an object of
Cake\Database\Connection
and schema Cake\Database\Schema\Collection
.
Note
If your table also does additional configuration in its initialize()
method,
those values will overwrite the ones provided to the registry.
You can also pre-configure the registry using TableLocator::setConfig()
.
Configuration data is stored per alias, and can be overridden by an object’s
initialize()
method:
// Prior to 3.6 use TableRegistry::setConfig()
TableRegistry::getTableLocator()->setConfig('Users', ['table' => 'my_users']);
Note
You can only configure a table before or during the first time you access that alias. Doing it after the registry is populated will have no effect.
During test cases you may want to flush the registry. Doing so is often useful when you are using mock objects, or modifying a table’s dependencies:
// Prior to 3.6 use TableRegistry::clear()
TableRegistry::getTableLocator()->clear();
If you have not followed the conventions it is likely that your Table or
Entity classes will not be detected by CakePHP. In order to fix this, you can
set a namespace with the Cake\Core\Configure::write
method. As an example:
/src
/App
/My
/Namespace
/Model
/Entity
/Table
Would be configured with:
Cake\Core\Configure::write('App.namespace', 'App\My\Namespace');