Laravel recursively eager load relations to paginate them

Hello Guys,

there is a problem that I have been struggling with for too long time yes it is the eager loading but not just simple eager loading first I will provide the exact same scenario for my case then I will show you some of my attempts finally I will leave it to you to help me anyway thanks in advance.

I have three Models Post , Comment , Reply each eager loads the other in the exact same order so Post eager loads Comment and Comment eager loads Reply for eager loading I use the help of protected $with property on the model itself.

now what I am trying to accomplish is to limit the records returned for relations loading with eager loading so if I have 100 post each has 50 comments and each comment has 10 replies I want to paginate the data as follows :

5 posts each post has 10 comments and each comment has 3 replies this is what I was fighting for but I couldn't get it right

what I tired so far

I tried to use limit and take on the "hasMany" on my model but never worked correctly I also tried to specify the perPage protected property on each model but as I realize this has nothing to do with pagination during eager loading I also tried to pass closures in the with protected property as ASSOC format to add eager loading constraints but it didn't work.

I don't want to make the question any longer I think this would be clear if not then I am ready to provide and more required details.

Please help thank you guys.

D9705996

7 years ago

Level 51

Have you tried constraining you eager loading, the below should give 5 posts with 10 comments each

$users = App\Post::with(['comments' => function ($query) {
    $query->take(10);
}])->take(5);

https://laravel.com/docs/5.3/eloquent-relationships#eager-loading

Not tried this so based on theory but seems right

istanbouly

7 years ago

Level 1

Yes I tried that but $query->paginate instead of take but it only works for the first element in the pagination like the second post will have a key called comments but that would be empty array.

Snapey

7 years ago

Level 122

This is an often asked for requirement, but there is no simple solution.

Here are some recent threads so that you can see the options.

https://laracasts.com/discuss/channels/eloquent/limit-post-number-per-category

@staudenmeir says he(?) has a package that will do this. I've not had need to try it. See the last response in the post above.

1 like

staudenmeir

7 years ago

Best Answer

Level 24

Thanks, @Snapey.

Yes, you can achieve this with my package: https://github.com/staudenmeir/eloquent-eager-limit

Use the HasEagerLimit trait in both the parent and the related model.

class Post extends Model {
    use \Staudenmeir\EloquentEagerLimit\HasEagerLimit;
}

class Comment extends Model {
    use \Staudenmeir\EloquentEagerLimit\HasEagerLimit;
}

Then you can apply limit()/take() to your relationships:

$posts = Post::with([
    'comments' => function ($query) {
        $query->limit(10);
    },
    'comments.replies' => function ($query) {
        $query->limit(3);
    }
])->paginate(5);

1 like

istanbouly

7 years ago

Level 1

Thank you such and awesome package you just save my work thanks a lot appreciate it and thank to all of you guys

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