Laravel 7.6 调用未定义的方法 Illuminate\Database\Eloquent\Builder::appends()

Question

I'm not being able to append the result with query. I'm filtering the result with category on the page and trying to add pagination. When a user clicks on category only category related products should be displayed and on pagination I want to keep the selected category. I'm getting this error:

Facade\Ignition\Exceptions\ViewException Call to undefined method Illuminate\Database\Eloquent\Builder::appends() (View: D:\Xampp\htdocs\ProjectName\resources\views\products\index.blade.php)

I have tried this from laravel docs

{{ $users->appends(['category' => 'query'])->links() }}

Here's my Controller:

 public function index(Request $request)
{

    // If the category is selected
    if(request()->category) {

        $products = Product::with('categories')->whereHas('categories', function ($query){
            $query->where('slug', request()->category);
        });

        $categories = Category::all();
        $categoryName =  optional($categories->where('slug', request()->category)->first())->name;

    }else {

        $products = Product::paginate(9);
        $categories = Category::all();
        $categoryName = 'All Products';

    }

    return view('products.index')->with([
        'products' => $products, 
        'categories' => $categories,
        'categoryName' => $categoryName,
        ]);
}

This is my blade file:

<h4>{{ $categoryName }}</h4>

                            @forelse ($products as $product)

                                <div class="card mb-3 shadow" style="">
                                    <div class="row no-gutters">

                                        <div class="col-md-4 d-flex justify-content-around p-2 border">
                                            <img src="/storage/products/{{ $product->image }}" class="card-img">
                                        </div>

                                        <div class="col-md-8 p-2">

                                            <div class="card-body">
                                                <h5 class="card-title">{{ $product->title}}</h5>
                                                <p class="card-text"> {!! \Illuminate\Support\Str::limit($product->text, $limit = 100) !!} </p>
                                                <div class=""><a href="/products/{{ $product->slug }}"><button class="btn btn-outline-warning float-left">View Cataloge</button></a>
                                                </div>
                                            </div>

                                        </div>
                                    </div>
                                </div>

                            @empty

                                <div class="card">
                                    <div class="card-title p-5 shadow bg-light">
                                        <h5>No products found</h5>
                                    </div>
                                </div>

                            @endforelse

                                <div class=" d-flex justify-content-around">
                                    {{ $products->appends(request()->input())->links() }}
                                </div>

Answer 1

Here you are missing paginate(9) also pass ($request) in closure function

public function index(Request $request)
{

    // If the category is selected
    if (!empty($request)) {
        $products = Product::whereHas('categories', function ($query) use ($request) {
            $query->where('slug', $request->category);
        })->paginate(9);

        $categories = Category::all();
        $categoryName =  optional($categories->where('slug', request()->category)->first())->name;

        return view('products.index')->with([
            'products' => $products, 
            'categories' => $categories,
            'categoryName' => $categoryName,
            ]);
    }
    else {

        $products = Product::paginate(9);
        $categories = Category::all();
        $categoryName = 'All Products';

        return view('products.index')->with([
            'products' => $products, 
            'categories' => $categories,
            'categoryName' => $categoryName,
            ]);

    }

}