Behaviors in CakePHP 1.2

1. Behaviors in CakePHP 1.2 Making your models behave CakeFest 08 Mariano Iglesias

2. Purpose of Models • Models encapsulate business logic • The more models do, the less controllers have to • They are not necessarily the PHP representation of a database table • They keep our code more manageable and readable

3. Purpose of Models • The skinny controllers / fat models approach • Taking it further: sexying up our application $comments = $this->Comment->find(‘all’, array( ‘conditions’ => array( ‘Comment.date’ => ‘<= ‘ . strtotime(‘-1 day’), ‘Comment.published’ => true ) )); foreach($records as $index => $record) { $records[$index][‘Comment’][‘by’] = $record[‘Author’][‘last’] . ‘, ‘ . $record[‘Author’][‘first’]; } versus: $comments = $this->Comment->last(‘1 day’);

4. Keeping Models DRY • The fatter models get, the more DRY they need to be • DRYing models the 1.1 way: AppModel • Orginizing AppModel by hierarchy AppModel MyModel method() AppModel SluggableModel method() MyModel

5. And then there was light: Behaviors • Behaviors are all about reusable model logic • They help us put models to diet: the skinny controllers / chubby models / athletic behaviors approach • They make our code even more readable, and help us solve the 1.1 AppModel multi-hierarchy problem

6. And then there was light: Behaviors • There are already a lot of behaviors out there: • Acl • Bindable / Containable • Sluggable • SoftDeletable • Taggable • Translate • Tree • Upload

7. Using Behaviors • Behaviors are attached to models through the actsAs model attribute: • A behavior can receive settings as an indexed array: class MyModel extends AppModel { var $name = ‘My’; var $actsAs = array(‘Bindable’); } class MyModel extends AppModel { var $name = ‘My’; var $actsAs = array(‘Bindable’ => array( ‘parameter’ => ‘value’, ‘parameter2’ => ‘value2’ )); }

8. Using Behaviors MyModel OtherModel BindableBehavior • There’s only one behavior instance per CakePHP instance: • A model can use several behaviors • Behaviors can also be specified at the AppModel level • Fresh from the owen: attach(), and detach()

9. Using Behaviors • Callbacks in behaviors: • beforeFind(&$Model, $query) • afterFind(&$Model, $results, $primary) • beforeValidate(&$Model) • beforeSave(&$Model) • afterSave(&$Model, $created) • beforeDelete(&$Model, $cascade) • afterDelete(&$Model) • onError(&$Model, $error) • Extending the model with methods in behaviors • Extending the new find syntax

10. Getting inside behaviors • Naming your behavior classes and files • A simple behavior skeleton • The $settings behavior property class MyBehavior extends ModelBehavior { function setup(&$Model, $settings = array()) { } function cleanup(&$Model) { } } class MyBehavior extends ModelBehavior { var $settings; function setup(&$Model, $settings = array()) { } // ……… }

11. Getting inside behaviors • Implementing callbacks in behaviors • Implementing model accesible methods in behaviors • Using other behaviors from a behavior: • App::import($behavior, ‘Behavior’) • Calling attach() and detach() class MyBehavior extends ModelBehavior { function beforeSave(&$Model) { $data = $Model->data[$Model->alias]; // ……… } }

12. Getting inside behaviors • Modifying and extending the find syntax $Model->find(‘all’, array( ‘parameter’ => ‘setting’ )); class MyBehavior extends ModelBehavior { function beforeFind(&$Model, $query) { if (isset($query[‘parameter’])) { // ……… } } }

13. Learning by example: SoftDeletable • Defining the purpose of the behavior • Identifying callbacks that need implementation: • beforeDelete: actual soft delete • beforeFind: get non soft-deleted records • beforeSave: disable soft deleted check before saving • afterSave: re-enable soft deleted check • Custom methods: • hardDelete • purge • undelete

14. Learning by example: SoftDeletable • Taking care of initialization and cleaning class SoftDeletableBehavior extends ModelBehavior { var $__settings = array(); function setup(&$Model, $settings = array()) { $default = array('field' => 'deleted', 'field_date' => 'deleted_date', 'delete' => true, 'find' => true); if (!isset($this->__settings[$Model->alias])) { $this->__settings[$Model->alias] = $default; } $this->__settings[$Model->alias] = array_merge($this->__settings[$Model->alias], ife(is_array($settings), $settings, array())); } function cleanup(&$Model) { } }

15. Learning by example: SoftDeletable function beforeDelete(&$Model, $cascade = true) { if ($this->__settings[$Model->alias]['delete'] && $Model->hasField($this->__settings[$Model->alias]['field'])) { $attributes = $this->__settings[$Model->alias]; $id = $Model->id; $data = array($Model->alias => array( $attributes['field'] => 1 )); if (isset($attributes['field_date']) && $Model->hasField($attributes['field_date'])) { $data[$Model->alias][$attributes['field_date']] = date('Y-m-d H:i:s'); } foreach(array_merge(array_keys($data[$Model->alias]), array('field', 'field_date', 'find', 'delete')) as $field) { unset($attributes[$field]); } if (!empty($attributes)) { $data[$Model->alias] = array_merge($data[$Model->alias], $attributes); } $Model->id = $id; $deleted = $Model->save($data, false, array_keys($data[$Model->alias])); if ($deleted && $cascade) { $Model->_deleteDependent($id, $cascade); $Model->_deleteLinks($id); } return false; } return true; }

16. Learning by example: SoftDeletable function beforeFind(&$Model, $queryData) { // ……… if (!empty($queryData['conditions']) && is_string($queryData['conditions'])) { $fields = array( $Db->name($Model->alias) . '.' . $Db->name($this->__settings[$Model->alias]['field']), $Db->name($this->__settings[$Model->alias]['field']), $Model->alias . '.' . $this->__settings[$Model->alias]['field'], $this->__settings[$Model->alias]['field'] ); foreach($fields as $field) { if (preg_match('/^' . preg_quote($field) . '[\s=!]+/i', $queryData['conditions']) || preg_match('/\\x20+' . preg_quote($field) . '[\s=!]+/i', $queryData['conditions'])) { $include = false; break; } } if ($include) { if (empty($queryData['conditions'])) { $queryData['conditions'] = array(); } if (is_string($queryData['conditions'])) { $queryData['conditions'] = $Db->name($Model->alias) . '.' . $Db->name($this->__settings[$Model->alias]['field']) . '!= 1 AND ' . $queryData['conditions']; } else { $queryData['conditions'][$Model->alias . '.' . $this->__settings[$Model->alias]['field']] = '!= 1'; } } } return $queryData; }

17. Conclusion • Questions? • Comments? • Standing round of applause? Mariano Iglesias mariano.iglesias@cricava.com