Laravel Livewire 3 dispatch issue

Question

I'm using Livewire 3. I want to pass some values to a function. Here are the related codes:

<div x-data="{ selectedDataTypes: [] }" class="space-x-0.5 space-y-1.5">
            <input type="checkbox" class="tag-checkbox" id="assetclass" x-model="selectedDataTypes" value="assetclass">
            <label class="tag" for="assetclass">Assets</label>

            <input type="checkbox" class="tag-checkbox" id="costcenter" x-model="selectedDataTypes" value="costcenter">
            <label class="tag" for="costcenter">Costs</label>

            <input type="checkbox" class="tag-checkbox" id="funcarea" x-model="selectedDataTypes" value="funcarea">
            <label class="tag" for="funcarea">Functional Areas</label>

            <input type="checkbox" class="tag-checkbox" id="fund" x-model="selectedDataTypes" value="fund">
            <label class="tag" for="fund">Funds</label>

            <button wire:click="$dispatch('syncSelected', selectedDataTypes)" class="btn-primary my-2">Sync Selected</button>

            <!-- Loading spinner -->
            <svg wire:loading wire:target="syncSelected" class="animate-spin ml-2 h-4 w-4 text-white" xmlns="http://www.w3.org/2000/svg" fill="none" viewBox="0 0 24 24">
                <circle class="opacity-25" cx="12" cy="12" r="10" stroke="currentColor" stroke-width="4"></circle>
                <path class="opacity-75" fill="currentColor" d="M4 12a8 8 0 018-8V0C5.373 0 0 5.373 0 12h4zm2 5.291A7.962 7.962 0 014 12H0c0 3.042 1.135 5.824 3 7.938l3-2.647z"></path>
            </svg>
        </div>

Livewire component:

class Data extends Component
{
    public $selectedDataTypes = [];

    #[On('syncSelected')]
        public function syncSelected(DataService $service)
        {
            // Check if none is selected
            if (empty($this->selectedDataTypes)) {
                dd($this->selectedDataTypes);
                session()->flash('error', 'Please select at least one data type to sync.');
                return;  // Early return to stop the execution here
            }
    
            try {
                $service->syncSelected($this->selectedDataTypes);
                session()->flash('success', 'Selected data synced successfully.');
            } catch (\Exception $e) {
                session()->flash('error', $e->getMessage());
            }
        }
}

Why am I getting an empty array [] in the dd()? Should I be using something else other than $dispatch? I've been going through the documentation for the last two hour with no progress. Please help. Thank you.

Answer 1

Answer

-> The reason why you are getting an empty array in the dd() is because the selectedDataTypes property is not being updated when the syncSelected event is dispatched. This is because the selectedDataTypes property is a local variable to the Data component, and it is not being passed to the syncSelected event.

-> To fix this, you can either pass the selectedDataTypes property to the syncSelected event, or you can use a global variable to store the selected data types.

-> Passing the selectedDataTypes property to the syncSelected event

-> To pass the selectedDataTypes property to the syncSelected event, you can add a $detail parameter to the $dispatch() method, and then pass the selectedDataTypes property to the $detail parameter.

public function syncSelected(DataService $service)
{
    // ...

    $this->dispatch('syncSelected', $this->selectedDataTypes);
}

-> Then, in the syncSelected event listener, you can access the selected data types using the $detail parameter.

#[On('syncSelected')]
public function syncSelected(DataService $service, $selectedDataTypes)
{
    // ...
}

-> If this is not helpfull then you need to use global method to fix this issue like this.

$selectedDataTypes = [];

class Data extends Component
{
    // ...

    #[On('syncSelected')]
    public function syncSelected(DataService $service)
    {
        global $selectedDataTypes;

        // ...

        $service->syncSelected($selectedDataTypes);
    }
}

-> and then in the syncSelected event dispatcher, you can update the global variable.

public function syncSelected(DataService $service)
{
    global $selectedDataTypes;

    // ...

    $selectedDataTypes = $this->selectedDataTypes;

    $this->dispatch('syncSelected');
}

-> Please inform me if you found any issue.