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How to implement a simple like system with Laravel

Benjamin Delespierre on June 29, 2020

This tutorial has been updated for Laravel 8 (I also fixed a few issues). A working implementation of this tutorial is also available on GitHub, e...

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Theo Harkenbusch • Aug 1 '20

Hey, thanks for the tutorial! However, I think there is a slight mistake in the Likes.php class.

It should be
return $likeable->likes()->whereHas('user', function(Builder $query) { return $query->whereId($this->id); })->exists();
rather than
return $likeable->likes()->whereHas('user', function($query) { return $query->whereId($this->id)->exists(); });

in Laravel 7.

mateator • Aug 2 '20 • Edited

Ty man, i have been stuck for weeks because of that, it wasnt working until you wrote to took out the ->exists();

same thing to delete, the result is:
$likeable->likes()->whereHas('user', function(Builder $query) { $query->whereId($this->id); })->delete();

Also, if someone implements this, dont forget to add this in Likes.php
use Illuminate\Database\Eloquent\Builder;

Benjamin Delespierre • Aug 2 '20

Yeah I removed the Builder typehint, it wasn't very helpful anyway.

stleroux • Jul 10 '21 • Edited

For some reason I get an error message when I try to post my own comment

Benjamin Delespierre • Aug 2 '20

My mistake. I'll change it, thanks for pointing it out

devkitshow • Oct 23 '20 • Edited

Hello! There's also a problem in LikesRequest

'id' => [
                "required",
                function ($attribute, $value, $fail) {
                    $class = $this->getClass($value);

                    if (! $class::where('id', $value)->exists()) {
                        $fail($value." is not present in database");
                    }
                },
            ],

this would give you an error due to getClass($value) is trying to get class of numeric id.
So it should probably be like

$class = $this->getClass($this->input('likeable'));

Benjamin Delespierre • May 27 '21

Thanks for pointing this out. I'm fixing the article as we speak to take your feedback into account. Stay tuned!

Benjamin Delespierre • May 27 '21

Should be fixed now. What do you think?

Deyvidbh • Aug 6 '20

Thank you very much for the tutorial! I have some doubts regarding how to implement this on my blade, I am a beginner. could you give me a tip? what do I put on my like button?

Benjamin Delespierre • Aug 6 '20 • Edited

assuming you've done everything in the tutorial right you should have a route "/like"

You can check it with php artisan route:list --name like

The button should look like this:

@if(!auth()->user()->hasLiked($post))
    <form action="/like" method="post">
        @csrf
        <input type="hidden" name="likeable" value="{{ get_class($post) }}">
        <input type="hidden" name="id" value="{{ $post->id }}">
        <button type="submit" class="btn btn-primary">
            Like
        </button>
    </form>
@else
    <button class="btn btn-secondary" disabled>
        {{ $post->likes()->count() }} likes
    </button>
@endif

I believe you can figure out how to make the unlike button by yourself with the resources provided in the tutorial ;-)

MD3108 • May 25 '21

Could u show how unlike works because I'm just managing to like but not dislike... #alsoBeginner

MD3108 • May 26 '21

I get this error when I try my dislikeSQLSTATE[22007]: Invalid datetime format: 1292 Truncated incorrect INTEGER value: 'like' (SQL: delete fromnoteswhereid= like

Benjamin Delespierre • May 27 '21

Sure, I think I'll update the article to add the views, stay tuned!

Benjamin Delespierre • May 27 '21

Aaaaand done. check it out!

MD3108 • May 27 '21

ohh nice, couldn't have hoped for better. I'll leave a comment on how it went once I get to it again!

Benjamin Delespierre • May 27 '21

most welcome my friend. You can also check this out, it's a working implementation of the like system github.com/bdelespierre/laravel-li...

MD3108 • May 29 '21

I managed to get as far as last time same error presists...
SQLSTATE[22007]: Invalid datetime format: 1292 Truncated incorrect INTEGER value: 'like' (SQL: delete fromnoteswhereid= like)`

however I think in 'app/Models/Concerns/Likes.php' the 'use App\Like' should be 'use App\Models\Like'. For the rest I got a flaw less exp. just don't know how to solve that issue there.

stleroux • Jun 12 '21

Hi,
Love the code. Straight forward and works like a charm.
Is there a way to eager load the likes data on index pages?
I tried adding "likes" to the with query but it doesn't seem to reduce the amount of queries being performed.

Thanks

Benjamin Delespierre • Jun 15 '21 • Edited

I have just tried

$posts = Post::latest()->with('likes')->take(5)->get();

Using the demo project and Laravel Debug bar.

From 8 queries (with the N+1) problem you mention, I now have only 4 👍

See before and after

Hint: be sure to place the ->with('...') part BEFORE ->get() or ->all().

stleroux • Jun 16 '21

Actually, I was using the code in the index page and doing a @can ('like') and @can ('unlike') which was querying the DB twice per record. I changed the @can ('unlike') for @else and now the duplicate queries are gone.
Thanks

Benjamin Delespierre • Jun 16 '21 • Edited

Yes, that's because the gates in AuthServiceProvider are using User::hasLike :

    public function hasLiked(Likeable $likeable): bool
    {
        if (! $likeable->exists) {
            return false;
        }

        return $likeable->likes()
            ->whereHas('user', fn($q) =>  $q->whereId($this->id))
            ->exists();
    }

You may change it to use a cache, like this (actual working solution) :

    public function hasLiked(Likeable $likeable): bool
    {
        if (! $likeable->exists) {
            return false;
        }

        return $this->likes->contains(
            fn($like) => $like->likeable_type == get_class($likeable) && $like->likeable_id == $likeable->id
        );
    }

It should minimize the number of queries. It's ugly but it works!

Result before with 15 queries (one per @can('like')) and after only 6!

Benjamin Delespierre • Jun 15 '21

Can you show us what you tried?

stleroux • Jul 9 '21

Hello,
I have run into a weird issue.
Wen I run the code on the localhost where I do my development, everything works fine.
This is a Windows 10 machine running PHP 7.4.15

However, when I transfer my files to my Ubuntu 18.04 server, I get the following error message on all pages :
->> syntax error, unexpected '=>' (T_DOUBLE_ARROW), expecting '{' <<-
And it is pointing to


      $likeable->likes()
        ->whereHas('user', function($q) => $q->whereId($this->id))
        ->delete();

in my User model.
I am running PHP 7.4.21 on the server.
If I comment out the lines, the pages load properly.
Hopefully, this is enough info to TS, if not, please let me know what else is needed.
Thanks

Benjamin Delespierre • Jul 10 '21

In the code snippet you provided, there's a typo on the arrow function, it should be:

      $likeable->likes()
        ->whereHas('user', fn($q) => $q->whereId($this->id))
        ->delete();

webfuelcode • Mar 2 '21 • Edited

I followed the steps, running the localhost says "trait app\concerns\likeable" not found... Tried a lot to figure out the reason but failed. It may be a typo or the new version is the reason. Can you tell me...

Benjamin Delespierre • Mar 10 '21

It's very unlikely a version issue (if you're running PHP7.2+ of course).

If you see the 'not found' error it means a namespace import is missing.

Benjamin • Mar 15 '22

Hello @bdelespierre

That's really brillant, thanks a lot for sharing!

I noticed an error in app/Http/Controllers/LikeController.php

Change
public function unlike(UnlikeRequest $like)
with
public function unlike(UnlikeRequest $request) ;-)

Thank you again,

FatahIdzhar • Sep 10 '21 • Edited

i get proble on
Undefined property: stdClass::$likes

flareapp.io/share/q5YLj4j7#F62

Benjamin Delespierre • Sep 10 '21

Your $model variable shouldn't be an stdClass instance. It should be a Post instance. (or anything with the Likes trait).

I suggest you dump this variable with dd($model) in the controller before returning the view and try to understand what's going on.

Good luck!

FatahIdzhar • Sep 10 '21 • Edited

I've tried it, it's still an error in the
Undefined property: stdClass::$likes

and already using dd()

Winner Onaolapo • Jul 20 '20

Thanks for this tutorial sir. Just curious is there a way to do this without having the user to sign in before liking a post? Thank you, sir

Benjamin Delespierre • Jul 20 '20

Well, you could tweak the design a bit by making the user_id nullable in order to create userless likes.

atr0x23 • Nov 12 '22

Hi, I am new to Laravel. I followed your orders here but when i am trying to run and see a view (blade) with the posts from db I am getting this error:

Trait 'App\Concerns\Likes' not found

What am I missing?
Thanks in advance.