mikehaertl\pdftk\Pdf Null

I'm developing a Laravel application and I'm trying to retrieve fields from a PDF file using mikehaertl\pdftk\Pdf but it always return NULL.

 public function postPdF(Request $request ){
    $file = $request->file('test');
    $content = fopen($file->getRealPath(),'r');
    $name = $file->getClientOriginalName();
    $extension = \File::extension($name);
    $newName = time().".".$extension;
    Storage::disk("local")->put($newName,$content);
    $pathF =  storage_path('app')."\\".$newName; 

    $pdf = new Pdf($pathF);
    $data = $pdf->getDataFields();

}    

If I do

var_dump($pdf)  

it returns

string(0) ""    

If I do

var_dump($data)   

it returns

bool(false)    

How can I fix this problem?

via Chebli Mohamed