How to create custom validation for Google Captcha without using any package?

To write custom validation for Google Captcha in Laravel without using a package, you’ll need to do the following:

1. Verify the Captcha response: You’ll need to send the Captcha response to the Google Captcha API and verify that it is valid. You can do this by sending a POST request to the following URL:

https://www.google.com/recaptcha/api/siteverify

You’ll need to include the following parameters in the request:

• secret: Your Captcha secret key.
• response: The Captcha response that was submitted by the user.
• remoteip: The IP address of the user.

The API will return a JSON response indicating whether the Captcha was successfully verified.

2. Create a custom validation rule: In your Laravel application, you can create a custom validation rule by creating a class that implements the Illuminate\Contracts\Validation\Rule interface. Here’s an example of a custom validation rule that verifies a Captcha response:

<?php

namespace App\Rules;

use Illuminate\Contracts\Validation\Rule;
use GuzzleHttp\Client;

class Captcha implements Rule
{
    /**
     * Determine if the validation rule passes.
     *
     * @param  string  $attribute
     * @param  mixed  $value
     * @return bool
     */
    public function passes($attribute, $value)
    {
        $client = new Client;
        $response = $client->post('https://www.google.com/recaptcha/api/siteverify', [
            'form_params' => [
                'secret' => env('CAPTCHA_SECRET'),
                'response' => $value,
                'remoteip' => request()->ip(),
            ],
        ]);
        $response = json_decode((string) $response->getBody());
        return $response->success;
    }

    /**
     * Get the validation error message.
     *
     * @return string
     */
    public function message()
    {
        return 'The Captcha verification failed. Please try again.';
    }
}

3. Use the custom validation rule: Once you’ve created your custom validation rule, you can use your custom validation rule in a form request or a controller by adding the rule to the rules array and using the validate method.

For example, if you want to use the custom validation rule in a form request, you can do the following:

<?php

namespace App\Http\Requests;

use App\Rules\Captcha;
use Illuminate\Foundation\Http\FormRequest;

class ContactRequest extends FormRequest
{
    /**
     * Determine if the user is authorized to make this request.
     *
     * @return bool
     */
    public function authorize()
    {
        return true;
    }

    /**
     * Get the validation rules that apply to the request.
     *
     * @return array
     */
    public function rules()
    {
        return [
            'name' => 'required',
            'email' => 'required|email',
            'message' => 'required',
            'captcha' => ['required', new Captcha],
        ];
    }
}

4. Then, in your controller action, you can use the validate method to validate the request:

public function store(ContactRequest $request)
{
    // The request is valid, so you can process the form data...
}

If the Captcha validation fails, the user will be redirected back to the form with an error message.