How to log changes of ActiveRecords?

Tutorials

A simple and effective way to keep track what your users are doing within your application is to log their activities related to database modifications. You can log whenever a record was inserted, changed or deleted, and also when and by which user this was done. For a [CActiveRecord] Model you could use a behavior for this purpose. This way you will be able to add log functionality to ActiveRecords very easily. First of all you have to create a table for the log-lines in the database. Here is an example (MySQL):     [sql]
 
CREATE TABLE ActiveRecordLog (
id INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
description VARCHAR(255) NULL,```php
class ActiveRecordLogableBehavior extends CActiveRecordBehavior
    { private $_oldattributes = array();
 
public function afterSave($event) {
 
if (!$this->Owner->isNewRecord) {

// new attributes// compare old and new
foreach ($newattributes as $name => $value) {
if (!empty($oldattributes)) {
$old = $oldattributes[$name];}


 
if ($value != $old) { //$changes = $name . ' ('.$old.') => ('.$value.'), '; $log=new ActiveRecordLog; $log->description= 'User ' . Yii::app()->user->Name . ' changed ' . $name . ' for ' . get_class($this->Owner)
 
                                            . ' changed ' . $name . ' for ' 
 
                                            . get_class($this->Owner) 
 
                                            . '[' . $this->Owner->getPrimaryKey() .'].';
$log->action= 'CHANGE';
$log->model= get_class($this->Owner);$log->userid= Yii::app()->user->id;
$log->save();

 
 
 
} } } else { $log=new ActiveRecordLog; $log->description= 'User ' . Yii::app()->user->Name
 
                                    . ' created ' . get_class($this->Owner)
 
                                    . '[' . $this->Owner->getPrimaryKey() .'].';
$log->action= 'CREATE';
$log->model= get_class($this->Owner);}


 
 
public function afterDelete($event) { $log=new ActiveRecordLog; $log->description= 'User ' . Yii::app()->user->Name . ' deleted ' . get_class($this->Owner)
 
                                . get_class($this->Owner) 
 
                                . '[' . $this->Owner->getPrimaryKey() .'].';
$log->action= 'DELETE';
$log->model= get_class($this->Owner);}


 
 
public function afterFind($event)
{
// Save old values```php
public function behaviors()
    { return array(     // Classname => path to Class      'ActiveRecordLogableBehavior'=>      'application.behaviors.ActiveRecordLogableBehavior', );     } }
```

Of course this simple example could be enhanced:

+ support for mult-column primary keys