# Troubleshooting

• Form Object and Model Binding
  • Can't set model as property if it hasn't been persisted yet
• Event Troubleshooting
• DispatchTo not working
  • Dispatch or DispatchTo not working or event not being caught
• Errors

# Form Object and Model Binding

# Can't set model as property if it hasn't been persisted yet

Livewire cannot re-hydrate a model that does not exist in the database, so you can not create a new blank model and pass it to a Livewire component. You can only pass a model that has been persisted to the database.

https://laracasts.com/discuss/channels/livewire/livewire-3-cant-set-model-as-property-if-it-hasnt-been-persisted-yet

# Event Troubleshooting

# DispatchTo not working

• Make sure you are using $dispatchTo and not just $dispatch

# Dispatch or DispatchTo not working or event not being caught

If you are dispatching to a dynamic component, make sure the component is available to listen to the event. For example, the code below will fail because the create-edit component is not available to listen to the event.

@foreach ($mediaItems as $media)
    <button wire:click="$dispatchTo('create-edit', 'set-editing-item', {id: {{ $>id }}})"> </button>
@endforeach

@isset($editing)
    <livewire:admin.media.media-create-edit :media="$editing" />
@endisset

What is the solution?

The solution is to dispatch the event to the parent component and then let the parent component handle the event.

# Errors

Error: Method Illuminate\Database\Eloquent\Collection::getMorphClass does not exist.

Livewire doesn't support custom queries, such as group by, selects, etc. when assigning models to properties. So you should use a computed property instead. See here for more details.

// Wrong way
public function mount(StudentCourse $studentCourse) {
    $studentCourse = $studentCourse->load('studentLessons.media.module');

    $this->groupedByModule = $studentCourse->studentLessons->groupBy(function ($studentLesson) {
        return $studentLesson->media->module->id;
    });

    $this->course = $studentCourse->course;
}

Computed properties are methods in your component marked with the #[Computed] attribute. They can be accessed as a dynamic property that isn't stored as part of the component's state but is instead evaluated on-the-fly.

Here's the above example re-written using a computed property:

#[Computed('groupedByModule')]
public function groupedByModule()
{
    return $this->studentCourse->studentLessons->groupBy(function ($studentLesson) {
        return $studentLesson->media->module->id;
    });
}

// Right way
public function mount(StudentCourse $studentCourse) {
    $this->studentCourse = $studentCourse->load('studentLessons.media.module');
    $this->course = $studentCourse->course;
}

Now you access the groupedByModule using $this->groupedByModule in your blade file.

Must access using this

@foreach ($this->groupedByModule as $moduleId => $lessons)
    // the rest of your code
@endforeach