Tracking database changes on related models... Laravel 5.1 - php

Question

We are trying to detect the changes in Laravel related models at attribute level, as we have to keep audit trail of all the changes which are made via the application.
We can track the changes via isDirty method on the Eloquent model for single model that is not related to any other model, but there is no way that we can track the changes on the related eloquent models. isDirty doesn't work on related models attributes. Can some one please help us on this?
Update to original question:
Actually we are trying to track changes on the pivot table that has extra attributes as well defined on it. IsDirty method doesn't work on those extra attributes which are defined in the pivot table.
Thanks

Answer 1

As much I understand your question, It's can achieve through Model Event and some sort of extra code with current and relation model.
Laravel Model Events
If you dont want to use any additional stuff, you can just use the Laravel Model Events (that in fact Ardent is wrapping in the hooks). Look into the docs http://laravel.com/docs/5.1/eloquent#events
Eloquent models fire several events, allowing you to hook into various
points in the model's lifecycle using the following methods: creating,
created, updating, updated, saving, saved, deleting, deleted,
restoring, restored.
Whenever a new item is saved for the first time, the creating and
created events will fire. If an item is not new and the save method is
called, the updating / updated events will fire. In both cases, the
saving / saved events will fire.
If false is returned from the creating, updating, saving, or deleting
events, the action will be cancelled:
Finally, reffering to your question you can utilize the above approaches in numerous ways but most obviously you can combine it (or not) with the Eloquent Models' getDirty() api docs here method and getRelation() api docs here method
It will work for example with the saving event.
Model::saving(function($model){
foreach($model->getDirty() as $attribute => $value){
$original= $model->getOriginal($attribute);
echo "Changed";
}
$relations = $model->getRelations();
foreach($relations as $relation){
$relation_model = getRelation($relation);
foreach($relation_model->getDirty() as $attribute => $value){
$original= $relation_model->getOriginal($attribute);
echo "Relation Changed";
}
}
return true; //if false the model wont save!
});
Another Thought might help you. when you saving
save() will check if something in the model has changed. If it hasn't it won't run a db query.
Here's the relevant part of code in Illuminate\Database\Eloquent\Model#performUpdate:
protected function performUpdate(Builder $query, array $options = [])
{
$dirty = $this->getDirty();
if (count($dirty) > 0)
{
// runs update query
}
return true;
}
The getDirty() method simply compares the current attributes with a copy saved in original when the model is created. This is done in the syncOriginal() method:
public function __construct(array $attributes = array())
{
$this->bootIfNotBooted();
$this->syncOriginal();
$this->fill($attributes);
}
public function syncOriginal()
{
$this->original = $this->attributes;
return $this;
}
check model is dirty isDirty():
if($user->isDirty()){
// changes have been made
}
Or check certain attribute:
if($user->isDirty('price')){
// price has changed
}
I did not check this code but hopeful to use as your answer by thoughts, if you have any confusion to deal such requirement or something need to optimize or change please let me know.