Behaviors
Behaviors allow to set and/or modify model field data by attaching the behavior to the model. A behavior can be implemented once an attached to different models, the number of behaviors that can be attached is unlimited.
A good example is a slug for a page, this is based on a title and needs to be updated during the commit. This slug can then be used in the URL to retrieve the model.
public function behavior()
{
return array(
// Guid generation
// Generate a guid and store in in the guid column
'Guid' => array('column' => 'guid'),
// Slug generation
// Generate a slug from the title column and store in in the slug column
'Slug' => array('source'=>'title', column' => 'slug'),
);
}
Behaviors types
Guid
This behavior will generate a GUID and store it in the specified column.
If the column key is ommited the ‘guid’ column will be used to store the generated GUID.
public function behavior()
{
return array(
...
'Guid' => array(
'column' => '[column name]'
),
...
);
}
Slug
This behavior will generate a slug from the source field and store it in the specified column.
If the source key is ommited the ‘name’ column will be used to create the slug. If the column key is ommited the ‘slug’ column will be used to create the slug.
public function behavior()
{
return array(
...
'Slug' => array(
'source' => '[column name]',
'column' => '[column name]'
),
...
);
}
LocalBehavior
Allows the creation of a local behavior that is model specific.
The function takes up to two arguments; the first argument contains the type of operation on the model and can be either ‘construct’ during construction of the model class, ‘update’ when the model is updated or ‘create’ when the model is created.
public function behavior()
{
return array(
...
// Callback static method
TRUE => array('MyClass::static_method'),
// Callback method
TRUE => array($this, 'custom_behavior')),
// Function as the callback (PHP 5.3+)
TRUE => function($action) {
// Do something to $value and return it.
return some_function($action);
},
...
);
}
Writing new behaviors
It is possible to create custom behaviors that can be reused in different models.
Create a subclass of the ORM_Behavior class and implement the on_construct, on_update and on_create functions.
class ORM_Behavior_MyBehavior extends ORM_Behavior {
/**
* Constructs a new model and loads a record if given
*
* @param ORM $model The model
* @param mixed $id Parameter for find or object to load
*/
public function on_construct($model, $id)
{
// return FALSE if the model is loaded from this function.
return TRUE;
}
/**
* The model is updated
*
* @param ORM $model The model
*/
public function on_update($model)
{
// Modify or update the appropriate fields
}
/**
* A new model is created, add a guid value
*
* @param ORM $model The model
*/
public function on_create($model)
{
// Modify or update the appropriate fields
}
}
