Call to a member function extension() on null when using the or operator

Question

so, I have two conditions which I wrap using if with "or" operator. previously it worked fine using the "and" operator, but when I only update one file upload it doesn't run, but if both file uploads the update is successful. to cover the shortcoming I thought of replacing it with the "or" operator, but it was an error.

my code,

if (Request()->sampul or Request()->buku <> "") {
        //upload gambar/foto dan buku
        $file = Request()->sampul;
        $fileName = Request()->slug . '.' . $file->extension(); //rename nama berdasarkan slug
        $file->move(public_path('file_buku'), $fileName);

        $file1 = Request()->buku;
        $fileName1 = Request()->nama . '.' . $file1->extension(); //rename nama berdasarkan nama
        $file1->move(public_path('file_buku'), $fileName1);

        $data = [
            'nama' => Request()->nama,
            'slug' => Request()->slug,
            'created_at' => Request()->created_at,
            'sampul' => $fileName,
            'buku' => $fileName1
        ]; 
        $this->BukuModel->editData($id_buku, $data);
    } else {
        //Jika tidak ingin ganti sampul dan buku
        $data = [
            'nama' => Request()->nama,
            'slug' => Request()->slug,
            'created_at' => Request()->created_at
        ];
        $this->BukuModel->editData($id_buku, $data);
    }

Answer 1

if (Request()->sampul or Request()->buku <> "") {
    //upload gambar/foto dan buku
    $file = Request()->sampul; //THIS IS NULL 
    $fileName = Request()->slug . '.' . $file->extension(); //

What your code is doing is run the if block if there is any non empty data for sampul or buku is not "" .So if any one of those 2 condition passed then the if block will run.

And your Request()->buku <> "" condition passed which means Request()->sampul is empty/null.

$file = Request()->sampul; //THIS IS NULL 
$fileName = Request()->slug . '.' . $file->extension(); //

Now in this code block you are trying to access the extension() from the null/empty value. So you are getting the error.

Your code should be something like:

        if (Request()->sampul || Request()->buku !== "") {
            //upload gambar/foto dan buku
            if (Request()->sampul) {
                $file     = Request()->sampul;
                $fileName = Request()->slug.'.'.$file->extension(); //rename nama berdasarkan slug
                $file->move(public_path('file_buku'), $fileName);
            }

            if (Request()->buku) {
                $file1     = Request()->buku;
                $fileName1 = Request()->nama.'.'.$file1->extension(); //rename nama berdasarkan nama
                $file1->move(public_path('file_buku'), $fileName1);
            }

            $data = [
                'nama'       => Request()->nama,
                'slug'       => Request()->slug,
                'created_at' => Request()->created_at,
                'sampul'     => $fileName,
                'buku'       => $fileName1
            ];
        } else {
            //Jika tidak ingin ganti sampul dan buku
            $data = [
                'nama'       => Request()->nama,
                'slug'       => Request()->slug,
                'created_at' => Request()->created_at
            ];
        }
        $this->BukuModel->editData($id_buku, $data);  

Also, using or and and is not a good practise. Try to use || and '&&' instead.