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Validation

Introduction​

WPN provides several different approaches to validate your application's incoming data. It is most common to use the validate method available on all incoming HTTP requests. However, we will discuss other approaches to validation as well.

WPN includes a wide variety of convenient validation rules that you may apply to data, even providing the ability to validate if values are unique in a given database table. We'll cover each of these validation rules in detail so that you are familiar with all of WPN's validation features.

Quickstart​

To learn about WPN's powerful validation features, let's look at a complete example of validating a form and displaying the error messages back to the user. By reading this high-level overview, you'll be able to gain a good general understanding of how to validate incoming request data using WPN:

Defining the route​

First we are assuming that you have created the following route:

Route::create('get_posts', GetPostsController::class);

Define the route callback​

<?php

namespace App\Http\Controllers;

use WPN\Http\Callback;
use WPN\Http\Response;

class GetPostsController implements Callback
{
    public function __invoke(): Response
    {
       //
    }
}

Writing the validation logic​

Now we are ready to fill in our store method with the logic to validate the new blog post. To do this, we will use the validate method provided by the WPN\Support\Request object. If the validation rules pass, your code will keep executing normally; however, if validation fails, an WPN\Validation\ValidatorException exception will be thrown and the proper error response will automatically be sent back to the user.

To get a better understanding of the validate method, let's jump back into the request:

GetPostsRequest.php
<?php

namespace App\Http\Requests;

use WPN\Support\Request;

class GetPostsRequest extends Request
{
    protected function rules(): array
    {
        return [
            'post_id' => ['required', 'int'],
        ];
    }
}

As you can see, the validation rules are passed into the rules array, using the field name as the key. Don't worry - all available validation rules are documented. Again, if the validation fails, the proper response will automatically be generated. If the validation passes, our controller will continue executing normally.

Responses​

Validation failures will return a 400 status response along with the fields that failed validation.

Validation failure response​

{
   "status":400,
   "failures":{
      "id":[
         "id is a required field"
      ]
   }
}

Modify validation failure messages​

Each rule has its own validation failure message, and you may also set a failure message for a field failing a specific validation rule

In your request you may overwrite the messages function of the WPN\Http\Request class. In this example we are overriding the message for the required rule on all fields. We are also overriding the string rule validation of the author field.

Get field name in validation message

%s in validation rule messages will be converted to the fields name.

GetPostsRequest.php
<?php

namespace App\Http\Requests;

use WPN\Http\Request;

class GetPostsRequest extends Request {
    public function rules(): array {
        return [
            'id'     => [ 'required' ],
            'author' => [ 'required', 'string' ]
        ];
    }

    protected function messages(): array {
        return [
            ...parent::messages(),
            'required'      => '%s has not been filled in!',
            'author.string' => 'The authors name must be a string'
        ];
    }
}

Available Validation Methods​

Required​

The field under validation must be present in the input data and not empty. A field is considered "empty" if one of the following conditions are true:

  • The value is null.
  • The value is an empty string.

String​

The field under validation must be a string. If you would like to allow the field to also be null, you should assign the nullable rule to the field.

Email​

The field under validation must be formatted as an email address.

Phone​

The field under validation must be formatted as a phone number.

Bool​

The field under validation must be able to be cast as a boolean. Accepted input are true, false, 1, 0, "1", and "0".

Date​

The field under validation must be a valid, non-relative date according to the strtotime PHP function.

Numeric​

The field under validation must be numeric.

Array​

The field under validation must be an array.