how to add new category in post page laravel - php

Question

when i want to make a post i have to first create a category on a different page, namely the category page, not the post page. how to make it like wordpress which can add categories and tags on the post page.
i have tried but i don't know how to make validation so that the category name and category slug (Str::slug) are unique.
after I tried to successfully add a category on the post page but when I added an existing category it still worked, not unique.
PostController.php
public function store(Request $request)
{
$this->validate($request,[
'name' => 'required',
'categories' => 'required',
]);
$slug = Str::slug($request->name);
$post = new Post();
$post->user_id = Auth::id();
$post->name = $request->name;
$post->slug = $slug;
$post->save();
// get old categories name
$existingCategory = $video->categories->pluck('name')->toArray();
// find new categories
foreach($request->categories as $category) {
if(! ( in_array($category, $existingCategory) ) ) {
//create a new category
$newCategory = new Category();
$newCategory->name = $category;
$newCategory->slug = Str::slug($category);
$newCategory->save();
}
}
$attachableCategory = [];
foreach($request->categories as $category) {
$attachableCategory[] = Category::where('name', $category)->pluck('id')->first();
}
$video->categories()->sync($attachableCategory);
return redirect()->route('admin.post.index');
}

Answer 1

It seem that your categories are an array. I they are. Problably your are looking for array validation
Validator::make($input, [
// validates there is an array
'categories' => 'required|array|min:1',
// validates values inside array
'categories.*' => 'required|string|min:4'
]);