[5.5] Add Model::only method

[sebastiandedeyne]

Adds an only method to the Model class that behaves like Request::only, to quickly extract attributes from a model to an array.

$user->only('first_name', 'last_name');
// ["first_name" => "Taylor", "last_name" => "Otwell"]

[tillkruss]

Why not use an array_map here?

[sebastiandedeyne]

Used the same style as Request::only

framework/src/Illuminate/Http/Concerns/InteractsWithInput.php

Line 144 in 78fedf7

public function only($keys)

[ntzm]

@tillkruss array_map won't work here because it's setting the key

[ghost]

It could be done with array_flip or array_combine (which I prefer) though.

[sebastiandedeyne]

Dot notation would be cool, but more complex since we're also dealing with accessors. I'm willing to update the PR if there's interest.

[ntzm]

This change has been rejected before: #15748

Hopefully this does get merged in though, I find myself wanting it in new projects quite a lot!

[sebastiandedeyne]

Regarding the previous PR feedback

Going to hold off on this since I feel like you could just do Arr::only($model->toArray()...

An upside of having this on the model is that you could call only on fields that are otherwise hidden.

[lucasmichot]

@sebastiandedeyne,

1. What about hidden attributes?
   With your PR, they are returned without any visibility control - which make them readable to anyone !!

$model = new EloquentModelStub;
// ...
$model->project = 'laravel';

// ...

$model->setHidden(['project']);
$this->assertEquals(['project' => 'laravel'], $model->only('project'));
// this test should have failed

2. What about non-existing attributes?

$model = new EloquentModelStub;
// ...
$model->project = 'laravel';

// ...

$this->assertEquals(['project' => 'laravel', 'foo_bar' => null]], $model->only(['project', 'foo_bar']));
// this test should fail

$this->assertEquals(['project' => 'laravel']], $model->only(['project', 'foo_bar']));
// this test should pass

---

Your function should only return:

return Arr::only(
    $this->attributesToArray(),
    is_array($attributes) ? $attributes : func_get_args()
);

[calebporzio]

@sebastiandedeyne - Needed this just yesterday! "what do you mean "->only" isn't defined???!!!"

[sebastiandedeyne]

@lucasmichot I disagree on your first point. This is the perfect escape hatch for retrieving a serialiazed version of the model despite the visibility attributes.

When calling only, you're declaring which attributes you want to extract. You can't accidentally share something with the world since it's explicit.