LoggableBehavior.php

<?php

namespace sammaye\audittrail;

use Yii;
use yii\base\Behavior;
use yii\db\ActiveRecord;

class LoggableBehavior extends Behavior
{
	private $_oldattributes = array();

	public $allowed = array();
	public $ignored = array();
	public $ignoredClasses = array();

	public $dateFormat = 'Y-m-d H:i:s';
	public $userAttribute = null;

	public $storeTimestamp = false;
	public $skipNulls = true;
	
	public function events()
	{
		return [
			ActiveRecord::EVENT_AFTER_FIND => 'afterFind',
			ActiveRecord::EVENT_AFTER_INSERT => 'afterInsert',
			ActiveRecord::EVENT_AFTER_UPDATE => 'afterUpdate',
			ActiveRecord::EVENT_AFTER_DELETE => 'afterDelete',
		];		
	}
	
	public function afterDelete($event)
	{
		$this->leaveTrail('DELETE');
	}
	
	public function afterFind($event)
	{
		$this->setOldAttributes($this->owner->getAttributes());
	}
	
	public function afterInsert($event)
	{
		$this->audit(true);
	}
	
	public function afterUpdate($event)
	{
		$this->audit(false);
	}

	public function audit($insert)
	{
		$allowedFields = $this->allowed;
		$ignoredFields = $this->ignored;
		$ignoredClasses = $this->ignoredClasses;

		$newattributes = $this->owner->getAttributes();
		$oldattributes = $this->getOldAttributes();

		// Lets check if the whole class should be ignored
		if(sizeof($ignoredClasses) > 0){
			if(array_search(get_class($this->owner), $ignoredClasses) !== false) return;
		}

		// Lets unset fields which are not allowed
		if(sizeof($allowedFields) > 0){
			foreach($newattributes as $f => $v){
				if(array_search($f, $allowedFields) === false) unset($newattributes[$f]);
			}

			foreach($oldattributes as $f => $v){
				if(array_search($f, $allowedFields) === false) unset($oldattributes[$f]);
			}
		}

		// Lets unset fields which are ignored
		if(sizeof($ignoredFields) > 0){
			foreach($newattributes as $f => $v){
				if(array_search($f, $ignoredFields) !== false) unset($newattributes[$f]);
			}

			foreach($oldattributes as $f => $v){
				if(array_search($f, $ignoredFields) !== false) unset($oldattributes[$f]);
			}
		}

		// If no difference then WHY?
		// There is some kind of problem here that means "0" and 1 do not diff for array_diff so beware: stackoverflow.com/questions/12004231/php-array-diff-weirdness :S
		if(count(array_diff_assoc($newattributes, $oldattributes)) <= 0) return;

		// If this is a new record lets add a CREATE notification
		if ($insert){
			$this->leaveTrail('CREATE');
		}

		// Now lets actually write the attributes
		$this->auditAttributes($insert, $newattributes, $oldattributes);
		
		// Reset old attributes to handle the case with the same model instance updated multiple times
		$this->setOldAttributes($this->owner->getAttributes());
	}

	public function auditAttributes($insert, $newattributes, $oldattributes = array())
	{
		foreach ($newattributes as $name => $value) {
			$old = isset($oldattributes[$name]) ? $oldattributes[$name] : '';

			// If we are skipping nulls then lets see if both sides are null
			if($this->skipNulls && empty($old) && empty($value)){
				continue;
			}

			// If they are not the same lets write an audit log
			if ($value != $old) {
				$this->leaveTrail($insert ? 'SET' : 'CHANGE', $name, $value, $old);
			}
		}
	}

	public function leaveTrail($action, $name = null, $value = null, $old_value = null)
	{
		$log			= new AuditTrail();
		$log->old_value = $old_value;
		$log->new_value = $value;
		$log->action	= $action;
		$log->model		= $this->owner->className(); // Gets a plain text version of the model name
		$log->model_id	= (string)$this->getNormalizedPk();
		$log->field		= $name;
		$log->stamp		= $this->storeTimestamp ? time() : date($this->dateFormat); // If we are storing a timestamp lets get one else lets get the date
		$log->user_id	= (string)$this->getUserId(); // Lets get the user id
		return $log->save();
	}
	
	public function getOldAttributes()
	{
		return $this->_oldattributes;
	}
	
	public function setOldAttributes($value)
	{
		$this->_oldattributes=$value;
	}	

	public function getUserId()
	{
		if(isset($this->userAttribute)){
			$data = $this->owner->getAttributes();
			return isset($data[$this->userAttribute]) ? $data[$this->userAttribute] : null;
		}else{
			try {
				$userid = Yii::$app->user->id;
				return empty($userid) ? null : $userid;
			} catch(Exception $e) { //If we have no user object, this must be a command line program
				return null;
			}
		}
	}

	protected function getNormalizedPk()
	{
		$pk = $this->owner->getPrimaryKey();
		return is_array($pk) ? json_encode($pk) : $pk;
	}
}