Figure what fields `save()` acted on if any (detecting changes) - laravel

Question

Doing ->save() and ->update() only updates when changes made, I think, is this true?
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;
}
I typically update like this:
public function update(Requests\UpdatePetRequest $request, Pet $pet)
{
$pet->update($request->all());
return $pet;
}
I want to figure from ->save and from ->update if what field names were updated? Along with what was the old value and the new value.
I currently manually do this like this:
public function update(Requests\UpdatePetRequest $request, Pet $pet)
{
$changes = [];
if ($request->exists('name') && $request->name != $pet->name) {
$changes['name'] = array([
'old' => $pet->name,
'new' => $request->name
]);
}
if ($request->exists('avatar') && $request->avatar != $pet->avatar) {
$changes['avatar'] = array([
'old' => $pet->avatar,
'new' => $request->avatar
]);
}
if (!count($changes)) {
return response()->json(['error'=>'No properties changed'], 422);
}
$pet->update($request->all());
$body = json_encode($changes);
$message = new Message(['body' => $body, 'kind' => 'PET_UPDATE']);
}
Is there an automated way to do this?

Answer 1

You can't do that with update(), but you can use getDirty() before save():
$model = Model::find($id);
$model->fill($request->all());
$cahnges = $model->getDirty();
$model->save();
getDirty() will return you an array with changed columns only, for example:
['name' => 'New Name', 'address' => 'New Street, 12']