Question

Sorry if the title is confusing but I’m trying to get all comments and their replies with a recursive function. The problem is the top-level comment object has a different data structure than the comments. The top-level comments are accessed from $comment_object->data->children while all comment replies are accessed from $comment->data->replies. This is what I have so far:

public function get_top_comments()
{
    $comments_object = json_decode(file_get_contents("http://www.reddit.com/comments/$this->id.json"));
    sleep(2); // after every page request

    $top_comments = array();
    foreach ($comments_object[1]->data->children as $comment)
    {
        $c = new Comment($comment->data);
        $top_comments[] = $c;
    }
    return $top_comments;
}

public function get_comments($comments = $this->get_top_comments) //<-- doesn't work
{
    //var_dump($comments);

    foreach ($comments as $comment)
    {
        if ($comment->data->replies != '')
        {
            //Recursive call
        }
    }
}

I tried to assign $comments = $this->get_top_comments as the default parameter of the recursive function but I guess PHP doesn’t support this? Do I have to use an if-else block within the function to separate the different structures?

Answer 1

I would just have the default value of get_comments() as NULL, then check if it’s null; if it is, use the top comments. You don’t want the comments passed to be NULL anyway.

public function get_comments($comments = NULL)
{
    //var_dump($comments);

    if (is_null($comments))
        $comments = $this->get_top_comments;

    foreach ($comments as $comment)
    {
        if ($comment->data->replies != '')
        {
            //Recursive call
        }
    }
}

This is how one example in the PHP docs does it. Note this comment in the docs:

The default value must be a constant expression, not (for example) a variable, a class member or a function call.