无法访问控制器中的变量（Laravel）

Question

I'm using Laravel 5 with Goutte for crawling, and I'm trying to extract links that I need, not all links. So, basic regex comes to scene. Regex is ok, tested online and it's working, but when I try to apply that regex in controller I'm getting an error. Here is what I tried:

<?php

namespace App\Http\Controllers;

use Illuminate\Http\Request;

use App\Http\Requests;
use App\Http\Controllers\Controller;

use Goutte\Client;

class RvnController extends Controller
{
    public function index()
    {


        $client = new Client();

        $crawler = $client->request('GET', 'http://www.jgpnis.rs/index.php/red-voznje-preuzimanje-pregled.html');

        $regex_rvn_links = "/http:\/\/www.jgpnis.rs\/red_voznje\/([a-zA-Z0-9\-])+\/([a-zA-Z0-9\-\.])+/";
        $links_array = array();

        $crawler->filter('a')->each(function ($node) use($links_array) {

            if (preg_match($regex_rvn_links , $node->link()->getUri())) {
                $links_array[] = $node->link()->getUri();
            }


        });

        dd($links_array);
    }
}

And error is like : ErrorException in RvnController.php line 27: Undefined variable: regex_rvn_links.

Ok, I tried to pass that error applying regex directly in preg_match and it's working, but my $links_array is empty. To not be confused, if I print $node->link()->getUri() instead pushing it to array,I get about 15 links, so it's working. But then, I cant use it like this, I need that array. So, my question is how to use variables in this situations, because non of them is working. What I'm missing?

Answer 1

You are using closure, need to pass variables into the closure correctly.

1) $regex_rvn_links must be passed into the closure. This is the cause of exception.

2) $links_array must be passed by reference (&$links_array). This is why you got empty array.

$crawler->filter('a')->each(function ($node) use (&$links_array, $regex_rvn_links) {
    if (preg_match($regex_rvn_links , $node->link()->getUri())) {
        $links_array[] = $node->link()->getUri();
    }
});