Date validation with another fields in controller in Laravel

Here is my validation code in the controller

 $eldate = Carbon::now()->addDay(4)->format('Y-m-d');

 $validatedData = $this->validate($request, [
        'ldate' => 'required|date|unique:leaves,ldate,NULL,employee,employee,'.auth()->id(),
        'ldate2'      => 'nullable|date|after_or_equal:ldate',
        'type' => 'required'
    ]);

In this validation code I have to add one more condition for date1

If type =2 then ldate should be greater than $eldate

use custom validation rules to solve the issue

$eldate = Carbon::now()->addDay(4);

     $validatedData = $this->validate($request, [
            'ldate' => ['required','date','unique:leaves,ldate,NULL,employee,employee,'.auth()->id(), function (string $attribute, mixed $value, Closure $fail) use ($request, $eldate) {
                if ($request->type==2 && $eldate->gt($value)) {
                    $fail("The {$attribute} is invalid.");
                }
            }],
            'ldate2'      => 'nullable|date|after_or_equal:ldate',
            'type' => 'required'
        ]);

For custom validation rules

Using Closures

Using Rule Objects

If you're using Laravel Form Request, then simply add

public function rules()
{
    $eldate = Carbon::now()->addDay(4)->format('Y-m-d');
    $rules = [
        'ldate' => ['required', 'date', Rule::unique('leaves', 'ldate')->where(function ($query) {
            return $query->where('employee', auth()->id());
        })],
        'ldate2' => 'nullable|date|after_or_equal:ldate',
        'type' => 'required',
    ];

    if ($this->input('type') == 2) {
        $rules['ldate'][] = 'after:' . $eldate;
    }

    return $rules;
}

I can show how to use Custom Class
documentation: https://laravel.com/docs/10.x/validation#custom-validation-rules

controller function code

public function test(Request $request)
    {
        $eldate = Carbon::now()->addDay(4);
        
        $rules = [
            'ldate'  => ['required', 'date', new ValidateDateTwo($eldate, $request->get('type'))],
            'ldate2' => ['nullable', 'date', 'after_or_equal:ldate'],
            'type'   => 'required'
        ];

        $validator = Validator::make($request->all(), $rules);

        if ($validator->fails()) {
            $messages = $validator->errors();
            $errors = [];
            foreach ($rules as $input => $rule) {
                foreach ($messages->get($input) as $key => $message) {
                    $errors[$input] = $message;
                }
            }

            return Response::json(['status' => false, 'errors' => $errors]);

        }


        return response()->json([
            'status' => 'success',
            'data' => [
                'ldate' => $request->get('ldate'),
                'ldate2' => $request->get('ldate2'),
                'type' => $request->get('type')
            ]
        ]);
    }

And the Validation Class

<?php

namespace App\Http\Controllers;

use Illuminate\Contracts\Validation\Rule;

class ValidateDateTwo implements Rule
{


    /**
     * @var mixed
     */
    private $eldate;
    /**
     * @var mixed
     */
    private $type;

    public function __construct($eldate, $type)
    {
        $this->eldate = $eldate;
        $this->type = $type;
    }
    public function passes($attribute, $value)
    {
        return $this->type != 2 || !$this->eldate->gt($value);
    }


    public function message()
    {
        return 'Your error message.';
    }
}

i have tested it for you.