webkernel/platform-forms
22-custom-fields
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title: Custom fields
Introduction
You may create your own custom field classes and views, which you can reuse across your project, and even release as a plugin to the community.
Custom field classes
To create a custom field class and view, you may use the following command:
php artisan make:platform-form-field LocationPickerThis will create the following component class:
use Webkernel\Platform\Forms\Components\Field;
class LocationPicker extends Field
{
protected string $view = 'platform.forms.components.location-picker';
}It will also create a view file at resources/views/webkernel/platform-forms/components/location-picker.blade.php.
<Aside variant="info"> Platform form fields are not Livewire components. Defining public properties and methods on a form field class will not make them accessible in the Blade view. </Aside>
Binding a field to its state
A field's state is stored in a public property on its Livewire component. Use $getStatePath() in the field's view to bind to the correct property, including when the field is nested inside a repeater or another component. You can bind with wire:model or entangle an Alpine.js property:
<x-dynamic-component
:component="$getFieldWrapperView()"
:field="$field"
>
<input wire:model="{{ $getStatePath() }}" />
<!-- Or -->
<div x-data="{ state: $wire.$entangle('{{ $getStatePath() }}') }">
<input x-model="state" />
</div>
</x-dynamic-component>See obeying state binding modifiers to support options such as live() and debounce(). Preserve the field's accessibility associations when creating its control markup.
If your field uses third-party JavaScript libraries, you can load its Alpine.js component asynchronously so those assets are only loaded when needed.
Accessing the state of another component in the Blade view
Inside the Blade view, you may access the state of another component in the schema using the $get() function:
<x-dynamic-component
:component="$getFieldWrapperView()"
:field="$field"
>
{{ $get('email') }}
</x-dynamic-component><Aside variant="tip"> Unless a form field is reactive, the Blade view will not refresh when the value of the field changes, only when the next user interaction occurs that makes a request to the server. If you need to react to changes in a field's value, it should be live(). </Aside>
Accessing the Eloquent record in the Blade view
Inside the Blade view, you may access the current Eloquent record using the $record variable:
<x-dynamic-component
:component="$getFieldWrapperView()"
:field="$field"
>
{{ $record->name }}
</x-dynamic-component>Accessing the current operation in the Blade view
Inside the Blade view, you may access the current operation, usually create, edit or view, using the $operation variable:
<x-dynamic-component
:component="$getFieldWrapperView()"
:field="$field"
>
@if ($operation === 'create')
This is a new conference.
@else
This is an existing conference.
@endif
</x-dynamic-component>Accessing the current Livewire component instance in the Blade view
Inside the Blade view, you may access the current Livewire component instance using $this:
@php
use Webkernel\Platform\Resources\Users\RelationManagers\ConferencesRelationManager;
@endphp
<x-dynamic-component
:component="$getFieldWrapperView()"
:field="$field"
>
@if ($this instanceof ConferencesRelationManager)
You are editing conferences the of a user.
@endif
</x-dynamic-component>Accessing the current field instance in the Blade view
Inside the Blade view, you may access the current field instance using $field. You can call public methods on this object to access other information that may not be available in variables:
<x-dynamic-component
:component="$getFieldWrapperView()"
:field="$field"
>
@if ($field->getState())
This is a new conference.
@endif
</x-dynamic-component>Adding a configuration method to a custom field class
You may add a public method to the custom field class that accepts a configuration value, stores it in a protected property, and returns it again from another public method:
use Webkernel\Platform\Forms\Components\Field;
class LocationPicker extends Field
{
protected string $view = 'platform.forms.components.location-picker';
protected ?float $zoom = null;
public function zoom(?float $zoom): static
{
$this->zoom = $zoom;
return $this;
}
public function getZoom(): ?float
{
return $this->zoom;
}
}Now, in the Blade view for the custom field, you may access the zoom using the $getZoom() function:
<x-dynamic-component
:component="$getFieldWrapperView()"
:field="$field"
>
{{ $getZoom() }}
</x-dynamic-component>Any public method that you define on the custom field class can be accessed in the Blade view as a variable function in this way.
To pass the configuration value to the custom field class, you may use the public method:
use App\Platform\Forms\Components\LocationPicker;
LocationPicker::make('location')
->zoom(0.5)Allowing utility injection in a custom field configuration method
Utility injection is a powerful feature of Platform that allows users to configure a component using functions that can access various utilities. You can allow utility injection by ensuring that the parameter type and property type of the configuration allows the user to pass a Closure. In the getter method, you should pass the configuration value to the $this->evaluate() method, which will inject utilities into the user's function if they pass one, or return the value if it is static:
use Closure;
use Webkernel\Platform\Forms\Components\Field;
class LocationPicker extends Field
{
protected string $view = 'platform.forms.components.location-picker';
protected float | Closure | null $zoom = null;
public function zoom(float | Closure | null $zoom): static
{
$this->zoom = $zoom;
return $this;
}
public function getZoom(): ?float
{
return $this->evaluate($this->zoom);
}
}Now, you can pass a static value or a function to the zoom() method, and inject any utility as a parameter:
use App\Platform\Forms\Components\LocationPicker;
LocationPicker::make('location')
->zoom(fn (Conference $record): float => $record->isGlobal() ? 1 : 0.5)Obeying state binding modifiers
When you bind a field to a state path, you may use the defer modifier to ensure that the state is only sent to the server when the user submits the form, or whenever the next Livewire request is made. This is the default behavior.
However, you may use the live() on a field to ensure that the state is sent to the server immediately when the user interacts with the field. This allows for lots of advanced use cases as explained in the reactivity section of the documentation.
Platform provides a $applyStateBindingModifiers() function that you may use in your view to apply any state binding modifiers to a wire:model or $wire.$entangle() binding:
<x-dynamic-component
:component="$getFieldWrapperView()"
:field="$field"
>
<input {{ $applyStateBindingModifiers('wire:model') }}="{{ $getStatePath() }}" />
<!-- Or -->
<div x-data="{ state: $wire.{{ $applyStateBindingModifiers("\$entangle('{$getStatePath()}')") }} }">
<input x-model="state" />
</div>
</x-dynamic-component>Calling field methods from JavaScript
Sometimes you need to call a method on the field class from JavaScript in the Blade view. For example, you might want to fetch data asynchronously, process a file upload, or perform some server-side computation. Platform provides a way to expose methods on your field class to JavaScript using the #[ExposedLivewireMethod] attribute.
Exposing a method
To expose a method to JavaScript, add the #[ExposedLivewireMethod] attribute to a public method on your custom field class:
use Webkernel\Platform\Forms\Components\Field;
use Webkernel\Platform\Support\Components\Attributes\ExposedLivewireMethod;
class LocationPicker extends Field
{
protected string $view = 'platform.forms.components.location-picker';
#[ExposedLivewireMethod]
public function geocodeAddress(string $address): array
{
// Perform geocoding logic...
return [
'latitude' => $latitude,
'longitude' => $longitude,
];
}
}<Aside variant="info"> Only methods marked with #[ExposedLivewireMethod] can be called from JavaScript. This is a security measure to prevent arbitrary method execution. </Aside>
Calling the method from JavaScript
In your Blade view, you may call the exposed method using $wire.callSchemaComponentMethod(). The first argument is the component's key (available via $getKey()), and the second argument is the method name. You may pass arguments as a third argument:
@php
$key = $getKey();
@endphp
<x-dynamic-component
:component="$getFieldWrapperView()"
:field="$field"
>
<div
x-data="{
address: '',
coordinates: null,
async geocode() {
this.coordinates = await $wire.callSchemaComponentMethod(
@js($key),
'geocodeAddress',
{ address: this.address },
)
},
}"
>
<input type="text" x-model="address" />
<button type="button" x-on:click="geocode">Geocode</button>
<template x-if="coordinates">
<p x-text="`${coordinates.latitude}, ${coordinates.longitude}`"></p>
</template>
</div>
</x-dynamic-component>Preventing re-renders
By default, calling an exposed method will trigger a re-render of the Livewire component. If your method doesn't need to update the UI, you may add Livewire's #[Renderless] attribute alongside #[ExposedLivewireMethod] to skip the re-render:
use Webkernel\Platform\Forms\Components\Field;
use Webkernel\Platform\Support\Components\Attributes\ExposedLivewireMethod;
use Webkernel\Liveview\Attributes\Renderless;
class LocationPicker extends Field
{
protected string $view = 'platform.forms.components.location-picker';
#[ExposedLivewireMethod]
#[Renderless]
public function geocodeAddress(string $address): array
{
// ...
}
}