Laravel factory relationships... respect create() or make() - php

Question

According to Laravel's documentation on defining relationships within model factories:
You may also attach relationships to models using Closure attributes in your factory definitions. For example, if you would like to create a new User instance when creating a Post, you may do the following:
$factory->define(App\Post::class, function ($faker) {
return [
'title' => $faker->title,
'content' => $faker->paragraph,
'user_id' => function () {
return factory(App\User::class)->create()->id;
}
];
});
The issue I'm running into is the reference to create() within the relationship definition. It seems to me that this doesn't belong here.
It works great if I am wanting to persist my relationships to the database:
factory(App\Post::class)->create();
By running the code directly above this, a new App\Post and a new App\User will be created and both persisted to the database.
But if I just want to new up the model(s) and not persist anything (at all) to the database by running:
factory(App\Post::class)->make();
It does what I want up to a certain point. A new App\Post instance is created but not persisted, however App\Comment is created and is persisted to the database.
It seems to me, that what I really want is something like this:
$factory->define(App\Post::class, function ($faker) {
return [
'title' => $faker->title,
'content' => $faker->paragraph,
'user_id' => function () {
// here I only want to declare the relationship,
// not decide whether I want to create() or make()
// the relationship, something like:
return factory(App\User::class)->createOrMake()->id;
// or perhaps something like:
return factory(App\User::class)->id;
}
];
});
The end result is that I want the related data to respect what I'm trying to do from the top of the call, down. Make everything. Or create everything.
Am I doing something wrong here? Or is this something that doesn't currently exist?
Thanks!

Answer 1

You want the lazy() method for your related models!
At least in Laravel 5.5.
I found your question here because I was having the same issue. I found the answer thanks to Laravel's beautifully written code -- lazy() was defined just above the make() XDebug took me to -- and I've tried it out and it seems to work.
This is what I'm doing:
$factory->define(App\ArtItem::class, function (Faker $faker) {
return [
// 'id' => $faker->randomDigit,
'slug' => $faker->unique->word,
'artist_id' => factory(App\Artist::class)->lazy(),
'image_id' => factory(App\Image::class)->lazy(),
'created_at' => $faker->dateTime,
'updated_at' => $faker->dateTime,
'deleted_at' => $faker->dateTime,
];
});
Lazy() is an interesting creature that returns a closure, so you can't do factory(App\Image::class)->lazy()->id but I'm still seeing it successfully setting the correct image_id and artist_id.
I certainly hope you found the solution long before this, but maybe this'll help someone else!

Answer 2

This is finally solvable now using Factory Callbacks added in Laravel 5.6.12.
$factory->afterMaking(Post::class, static function (Post $post) {
if (!$post->user_id) {
$post->user()->associate(factory(User::class)->make(['id' => 0]));
}
});
$factory->afterCreating(Post::class, static function (Post $post) {
if (!$post->user_id) {
$post->user()->associate(factory(User::class)->create())->save();
}
});
Now, whenever you make a Post, if you don't pass it a user_id, it will make a User for you and set the relationship without saving it. But if you create a Post, it will persist a new User to the database and save its ID to the Post model.
Note that both the afterMaking and afterCreating closures are called when you create a factory model. I am temporarily setting the User id to 0 in case the foreign key posts.user_id was defined not null. It will be updated to the correct value in afterCreating. This is a terrible hack, but it works until we get a proper beforeCreating hook which would allow us to create the related model first.