Laravel - How to Validate Grading System in Model and Controller - laravel

Question

I am developing A web Application using Laravel-5.8 framework. I have a Model Class as shown below:
<?php
namespace App;
use App\Model;
class Gradesystem extends Model
{
protected $table = 'grade_systems';
}
Also my Controller is shown below:
public function store(Request $request){
$request->validate([
'grade_system_name' => 'required|string|max:255',
'point' => 'required',
'grade' => 'required',
'from_mark' => 'required',
'to_mark' => 'required',
]);
$gpa = new Gradesystem;
$gpa->grade_system_name = $request->grade_system_name;
$gpa->point = $request->point;
$gpa->grade = $request->grade;
$gpa->from_mark = $request->from_mark;
$gpa->to_mark = $request->to_mark;
$gpa->save();
}
How do I validate, probably from the Model or the Controller between from_mark and to_mark. Also, from_mark should not be greater that or equal to to_mark.
It must not allow a number that falls in the range of already existing value. For example if from_mark is 0 and to_mark is 49 are already in database. So, if a user enters from_mark or to_mark to be 30, it must not allow it.
How do I achieve this?
Thank you.

Answer 1

For custom Validations its better use Rule Objects, where you can implement the logic of your validation.
An Example:
<?php
namespace App\Rules;
use Illuminate\Contracts\Validation\Rule;
class Uppercase implements Rule
{
/**
* Determine if the validation rule passes.
*
* #param string $attribute
* #param mixed $value
* #return bool
*/
public function passes($attribute, $value)
{
return strtoupper($value) === $value;
}
/**
* Get the validation error message.
*
* #return string
*/
public function message()
{
return 'The :attribute must be uppercase.';
}
}
You can see the info in the Laravel documentation
Hope this can help you

Answer 2

I did not understand entire validation you asked but this will help. With same way you can write any other validation on from_mark and to_mark.
$validator = Validator::make($request->all(), [
'grade_system_name' => 'required|string|max:255',
'point' => 'required',
'grade' => 'required',
'from_mark' => 'required',
'to_mark' => 'required',
]);
if ($validator->fails()) {
return redirect()->back()->withInput()->withErrors();
}
if ($request->get('from_mark') < $request->get('to_mark')) {
return redirect()->back()->withInput()->withErrors();
}