Livewire how to $emit event on select change (wire:model)

Question

Livewire how to $emit event on <select> change (wire:model)

I need to fire event (fetch some data from DB in another component) on simple <select> change.

<select id="hall" wire:model="hall_id">...</select>

How to watch changes for this model? On VueJS we just set $watch or $computed properties, I believe in livewire should be something similar. It's strange why there is no wire:change directive.

This is how I'm trying to emit event now:

<?php

namespace App\Http\Livewire;

use App\Models\Event;
use App\Models\Hall;
use Livewire\Component;

class ShowReservationForm extends Component
{
    public $hall_id = '';

    protected $queryString = [
        'hall_id' => ['except' => ''],
    ];

    public function mounted()
    {
        //
    }

    public function updatedHallId($name, $value)
    {
        $this->emit('hallChanged', $value);
    }

    public function render()
    {
        return view('livewire.show-reservation-form', [
            'halls' => Hall::all(),
        ]);
    }

    public function getHallEventsProperty()
    {
        return Event::where('hall_id', $this->hall_id)->get();
    }
}

and catch it:

<?php

namespace App\Http\Livewire;

use Livewire\Component;

class ShowReservations extends Component
{
    protected $listeners = ['hallChanged'];

    public $showTable = false;

    public function render()
    {
        return view('livewire.show-reservations');
    }

    public function hallChanged()
    {
        $this->showTable = true;
    }
}

Must be missing something obvious.

Answer 1

It's turns out that when receiving event, property value must not be bool?

This will not work:

public $showTable = false;
...
public function hallChanged()
    {
        $this->showTable = true;
    }

This will work

public $showTable = 0;
...
public function hallChanged()
    {
        $this->showTable = 1;
    }

Answer 2

use wire:change

<select id="hall" wire:model="hall_id" wire:change="change">...</select>

then in component

In ShowReservationForm.php

public function change()
{
     $this->emit('hallChanged'); 
}

then you can listen it on ShowReservations component ref link https://laravel-livewire.com/docs/2.x/events

in ShowReservations.php

 protected $listeners = ['hallChanged' => 'change'];

public function change()
{
   $this->showTable = true;
}

Answer 3

If the code not works, take a look about any [for example jQuery] handle for your select, maybe it handled by select2 script or so, if so - LiveWire will not work from scratch. The rigth minimal code is:

/resources/views/livewire/your-livewire-component.blade.php

<select wire:model="country">
    @foreach($items as $code => $country)
        <option value="{{ $code }}">{{ $country }}</option>
    @endforeach
</select>

/app/Http/Livewire/YourLivewireComponent.php

<?php
namespace App\Http\Livewire;
use Illuminate\Support\Facades\Log;
use Livewire\Component;
class YourLivewireComponent extends Component
{
    public $items;
    public $country; //necessary!
    public function mount($items)
    {
        $this->items = $items;
    }

    public function render()
    {
        return view('livewire.your-livewire-component', [
            'items' => ['ES' => 'Spain', 'FI' => 'Finland']
        ]);
    }

    public function updatedCountry($value)
    {
        Log::info('value='.print_r($value, 1));
    }
}

/resources/views/somelaraveltemplate.blade.php

<p>some HTML code</p>
@livewire('your-liveweire-component')