Add the Conditionable trait to the FormBuilder

[ash-jc-allen]

Hey! This PR proposes adding the Illuminate\Support\Traits\Conditionable trait to the Laravel\Prompts\FormBuilder class.

I love using when in my Laravel apps so I can chain my method calls together. So I reached out today to use it when building a form in Prompts and noticed it didn't exist.

Here's an example use case of a form using a standard if statement to add a new user to the app:

// Imagine this is coming from config or something like that...
$smsEnabled = true;

$form = form()
    ->text(
        label: 'Email:',
        required: true,
        validate: ['email'],
        name: 'email'
    );

if ($smsEnabled) {
    $form->text(label: 'Phone number:', name: 'phone_number');
    $form->confirm(label: 'Send Welcome SMS?', name: 'send_sms');
}

$formData = $form->submit();

Using when it could be rewritten like so:

// Imagine this is coming from config or something like that...
$smsEnabled = true;

$formData = form()
    ->text(
        label: 'Email:',
        required: true,
        validate: ['email'],
        name: 'email'
    )
    ->when(
        $smsEnabled,
        function (FormBuilder $form): void {
            $form->text(label: 'Phone number:', name: 'phone_number');
            $form->confirm(label: 'Send Welcome SMS?', name: 'send_sms');
        },
    )
    ->submit();

I did notice that Prompts isn't specific to Laravel and can be used in other PHP apps, so I don't know if keeping the dependencies lightweight will play a part in the decision to merge this. But from looking at the Composer files, I think Prompts includes illuminate/collections which in turn requires illuminate/conditionable. So if I'm right, it means we already have access to this trait without needing to add any new dependencies.

If this is something you think might be helpful to other devs, please give me a shout if you might want anything changed on this PR. If not, that's totally cool, at least I gave it a shot! 😄

[driesvints]

Sorry @ash-jc-allen but I want to advocate against this change as we're actually looking at removing the illuminate/support dependency entirely in the near future. It's now a circular dependency with framework core and we want to get rit of this. Adding functionality now which we'll have to remove later on doesn't help 😞

[ash-jc-allen]

Hey @driesvints! That's totally cool, I had a feeling the dependencies might have been a bit of a concern 🙂

[driesvints]

Cool. Gonna close this then.