Tukukkk

So I am trying to write the following function in the App Service Provider but am getting errors:

My code is:

public function boot()

{

    $homepage = 'https://example.com';

    $already_crawled = ;

    $crawling = ;



    function follow_links($url)

    {

        global $already_crawled;

        global $crawling;



        $doc = new DOMDocument();

        $doc->loadHTML(file_get_contents($url));



        $linklist = $doc->getElementsByTagName('a');



        foreach ($linklist as $link) {

            $l = $link->getAttribute("href");

            $full_link = 'https://example.com' . $l;



            if (!in_array($full_link, $already_crawled)) {

                $already_crawled = $full_link;

                $crawling = $full_link;

                Log::info($full_link . PHP_EOL);

            }

        }



        array_shift($crawling);

        foreach ($crawling as $link) {

            follow_links($link);

        }

    }



    follow_links($homepage);

}

So with this code I am getting errors like:

in_array() expected parameter 2 to be array, null given

What should I do to run this without problems?

Your variables in your boot function aren't global, so your follow_links function's globals are a totally separate set of variables. You should basically never have the keyword global anywhere in Laravel, ever.

Because of your scope issues, $already_crawled is undefined when you first attempt to feed it to is_array. Use class properties, and $this to access them. On top of that, I've removed the weird function-in-a-function construction:

protected $already_crawled;

protected $crawling;

protected $homepage;



public function boot()

{

    $this->homepage = 'https://example.com';

    $this->already_crawled = ;

    $this->crawling = ;



    $this->follow_links($this->homepage);

}



protected function follow_links($url)

{

    $doc = new DOMDocument();

    $doc->loadHTML(file_get_contents($url));



    $linklist = $doc->getElementsByTagName('a');



    foreach ($linklist as $link) {

        $l = $link->getAttribute("href");

        $full_link = 'https://example.com' . $l;



        if (!in_array($full_link, $this->already_crawled)) {

            $this->already_crawled = $full_link;

            $this->crawling = $full_link;

            Log::info($full_link . PHP_EOL);

        }

    }



    array_shift($this->crawling);

    foreach ($this->crawling as $link) {

        $this->follow_links($link);

    }

}

Side note: You almost certainly don't want this in your service provider. It's going to make a HTTP file_get_contents call on every single pageview your app ever serves. It's going to slow your app down dramatically.