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Behaviors are attached to models through the $actsAs model class variable:

<?php

class Category extends AppModel {
    var $name   = 'Category';
    var $actsAs = array('Tree');
}

?>

1. <?php
2. class Category extends AppModel {
3. var $name = 'Category';
4. var $actsAs = array('Tree');
5. }
6. ?>

This example shows how a Category model could be managed in a tree structure using the TreeBehavior. Once a behavior has been specified, use the methods added by the behavior as if they always existed as part of the original model:

// Set ID
$this->Category->id = 42;

// Use behavior method, children():
$kids = $this->Category->children();

1. // Set ID
2. $this->Category->id = 42;
3. // Use behavior method, children():
4. $kids = $this->Category->children();

Some behaviors may require or allow settings to be defined when the behavior is attached to the model. Here, we tell our TreeBehavior the names of the "left" and "right" fields in the underlying database table:

<?php

class Category extends AppModel {
    var $name   = 'Category';
    var $actsAs = array('Tree' => array(
        'left'  => 'left_node',
        'right' => 'right_node'
    ));
}

?>

1. <?php
2. class Category extends AppModel {
3. var $name = 'Category';
4. var $actsAs = array('Tree' => array(
5. 'left' => 'left_node',
6. 'right' => 'right_node'
7. ));
8. }
9. ?>

We can also attach several behaviors to a model. There's no reason why, for example, our Category model should only behave as a tree, it may also need internationalization support:

<?php

class Category extends AppModel {
    var $name   = 'Category';
    var $actsAs = array(
    	'Tree' => array(
          'left'  => 'left_node',
          'right' => 'right_node'
    	),
    	'Translate'
    );
}

?>

1. <?php
2. class Category extends AppModel {
3. var $name = 'Category';
4. var $actsAs = array(
5. 'Tree' => array(
6. 'left' => 'left_node',
7. 'right' => 'right_node'
8. ),
9. 'Translate'
10. );
11. }
12. ?>

So far we have been adding behaviors to models using a model class variable. That means that our behaviors will be attached to our models throughout the model's lifetime. However, we may need to "detach" behaviors from our models at runtime. Let's say that on our previous Category model, which is acting as a Tree and a Translate model, we need for some reason to force it to stop acting as a Translate model:

// Detach a behavior from our model:
$this->Category->Behaviors->detach('Translate');

1. // Detach a behavior from our model:
2. $this->Category->Behaviors->detach('Translate');

That will make our Category model stop behaving as a Translate model from thereon. We may need, instead, to just disable the Translate behavior from acting upon our normal model operations: our finds, our saves, etc. In fact, we are looking to disable the behavior from acting upon our CakePHP model callbacks. Instead of detaching the behavior, we then tell our model to stop informing of these callbacks to the Translate behavior:

// Stop letting the behavior handle our model callbacks
$this->Category->Behaviors->disable('Translate');

1. // Stop letting the behavior handle our model callbacks
2. $this->Category->Behaviors->disable('Translate');

We may also need to find out if our behavior is handling those model callbacks, and if not we then restore its ability to react to them:

// If our behavior is not handling model callbacks
if (!$this->Category->Behaviors->enabled('Translate')) {
	// Tell it to start doing so
	$this->Category->Behaviors->enable('Translate');
}

1. // If our behavior is not handling model callbacks
2. if (!$this->Category->Behaviors->enabled('Translate')) {
3. // Tell it to start doing so
4. $this->Category->Behaviors->enable('Translate');
5. }

Just as we could completely detach a behavior from a model at runtime, we can also attach new behaviors. Say that our familiar Category model needs to start behaving as a Christmas model, but only on Christmas day:

// If today is Dec 25
if (date('m/d') == '12/25') {
	// Our model needs to behave as a Christmas model
	$this->Category->Behaviors->attach('Christmas');
}

1. // If today is Dec 25
2. if (date('m/d') == '12/25') {
3. // Our model needs to behave as a Christmas model
4. $this->Category->Behaviors->attach('Christmas');
5. }

We can also use the attach method to override behavior settings:

// We will change one setting from our already attached behavior
$this->Category->Behaviors->attach('Tree', array('left' => 'new_left_node'));

1. // We will change one setting from our already attached behavior
2. $this->Category->Behaviors->attach('Tree', array('left' => 'new_left_node'));

There's also a method to obtain the list of behaviors a model has attached. If we pass the name of a behavior to the method, it will tell us if that behavior is attached to the model, otherwise it will give us the list of attached behaviors:

// If the Translate behavior is not attached
if (!$this->Category->Behaviors->attached('Translate')) {
	// Get the list of all behaviors the model has attached
	$behaviors = $this->Category->Behaviors->attached();
}

1. // If the Translate behavior is not attached
2. if (!$this->Category->Behaviors->attached('Translate')) {
3. // Get the list of all behaviors the model has attached
4. $behaviors = $this->Category->Behaviors->attached();
5. }