Add field-level and resource-level validation support

[phpfour]

Related Issues

Original Issue: #3

Context and Purposes

In order to further simplify the usage of a CrudResource, the validations rules for the fields should reside in the CrudResource itself and/or to the fields themselves.

Challenges and Solutions

Field-level Validation Rules

In this update, we have added both the above support. Here's an example of using field level validation rules:

public function fields(): array
{
    $id = $this->crud->getRequest()->input('id') ?? $this->crud->getRequest()->route('id');

    return [
        Text::make('Name')
            ->rules('required', 'min:5', 'max:255')
            ->sortable(),

        Email::make('Email')
            ->rules('required')
            ->creationRules('unique:users,email')
            ->updateRules('unique:users,email,'.$id),

        Password::make('Password')
            ->size(6)
            ->rules(['confirmed', 'min:8'])
            ->onlyOnForms(),

        Password::make('Confirm Password', 'password_confirmation')
            ->size(6)
            ->creationRules('required')
            ->onlyOnForms(),
    ];
}

As shown in the example, there are three methods to use:

• rules: adds the validation rule for both create and update forms
• creationRules: adds the validation rule only for create form
• updateRules: adds the validation rule only for update form

Resource-level Validation Rules

In addition to the field-level validation, the validation rules/messages can also be added to the CrudResource itself. Example:

/** @inheritDoc */
public function validationRules(): array
{
    $id = $this->crud->getRequest()->get('id') ?? $this->crud->getRequest()->route('id');

    $rules = [
        'name' => 'required|min:5|max:255',
        'role' => 'required',
    ];

    $rules['email'] = $this->crud->getOperation() === 'create'
        ? 'required|unique:users,email'
        : 'required|unique:users,email,'.$id;

    $rules['password'] = $this->crud->getOperation() === 'create'
        ? 'required|confirmed'
        : 'confirmed';

    return $rules;
}

/** @inheritDoc */
public function validationMessages(): array
{
    return [
        'name.required' => 'You gotta give it a name, man.',
        'name.min' => 'You came up short. Try more than 2 characters.',
    ];
}

[phpfour]

Hey @tabacitu, let me know what you think 🙂

[tabacitu]

Awesome! Haven't done a proper code review. Ran through this from a developer's perspective though, and only one potential problem stands out to me, see below.

[tabacitu]

This is where validation + declarative syntax becomes a bit tricky, so bear with me please 😀 I'm not sure about using creationRules() and updateRules(). Why? Because people also have other operations that use Backpack fields. And this month (or next month the latest), we'll share tutorials and add a feature to DevTools to easily create operations that use Backpack forms (eg. Moderate, Reply, Ship, etc.). If creationRules() and updateRules() are hard-coded... it means there's no way devs can use this Resource syntax on custom operations, which... is not the end of the world, but... it's a shame.

Then again, the alternative isn't great either.

---

In Backpack v3.x we were pointing to the operation where those rules apply:

$this->crud->setFormRequest(ArticleRequest::class, 'create');
$this->crud->setFormRequest(ArticleRequest::class, 'update');

That was because we thought it would be easy to just define everything in one place (in Backpack's case, in the setup() method). But after working on complex projects... it turns out for medium-complexity and high-complexity projects, you probably want to define each operation individually. So we came up with setupListOperation(), setupCreateOperation() and setupUpdateOperation().

Ok so that's the history 😅 What can we do here?

---

If this is indeed a problem worth solving (debatable), I see two options:

(A) magic methods that follow a convention, starting from the operation name (eg. if you do updateRules() or createRules() or replyRules() even though that method doesn't exist, it will work; downside: magic, no IDE auto-completion;

(B) extra parameter for the rules() method, eg.

• ->rules('required|min:5', 'create');
• ->rules('required|min:5', ['create', 'update']);
• ->rules('required|min:5'); // if missing it can default to both create and update