Dynamic FormRequest Validation (Laravel) - php

Question

Is it possible to create a dynamic FormRequest validation in my function? See sample code below.
public function store(Request $request)
{
Model::create($request->all());
return redirect(url('/'));
}
What I mean is that I will change the "Request" parameter to the variable $formRequest.
My goal is that I would like to create different validation rules for a dynamic set of data of a single model.
If I could achieve this with other ways, please let me know. Thank you!
Edit:
Sample scenario:
I have a form that has fields of First Name, Middle Name and Last Name.
First Rule:
public function rules()
{
return [
'firstname' => 'required',
'middlename' => 'required',
'lastname' => 'required'
];
}
Second Rule:
public function rules()
{
return [
'firstname' => 'required',
'lastname' => 'required'
];
}
Where in the second rule only requires first and last name.
I just want to know if there are other ways of doing this rather than creating multiple store methods and adding more routes.

Answer 1

Skipping FormRequest and using the validate method on the $request instance can achieve this. Laracasts even has a lesson on it.
public function store(Request $request) {
$rules = [/*...*/];
$attributes = $request->validate($rules);
Model::create($attributes);
return redirect(url('/'));
}

Answer 2

You can create a custom request:
php artisan make:request CustomRequest
This will generate this class:
class CustomRequest extends FormRequest
{
/**
* Determine if the user is authorized to make this request.
*
* #return bool
*/
public function authorize()
{
return false;
}
/**
* Get the validation rules that apply to the request.
*
* #return array
*/
public function rules()
{
return [
//
];
}
}
The authorize() method will determine if the request can be validated in the first place.
The rules() method will return the validation rules for the current request.
And then in your controller function:
public function yourfunction(CustomRequest $request)

Answer 3

In the validation rules you can simply add the "sometimes" rule. You can find it here https://laravel.com/docs/5.7/validation#conditionally-adding-rules
public function rules()
{
return [
'firstname' => 'required',
'middlename' => 'sometimes|required',
'lastname' => 'required'
];
}