How can I see exactly what arguments are being passed through a filter so that I may modify them?

Question

I'm having a great deal of trouble phrasing this.

If I were to use the filter

views_edit-page

How can I see what exactly is being passed through the filter so that I may edit them? Normally I would var_dump something similar to this, to get a breakdown of it's contents, but due to it being a filter, this does not seem to work.

For example

add_filter('views_edit-page','addFilter');

function addFilter($views) {
  var_dump($views);
  die();
}

Is what I'd like to do, so that I may see exactly what $views consists of, in order to edit them. However, this does not work, what is a method I can use in order to see the content of $views?

Answer 1

Perhaps you could push the variable contents to error log for later inspection? Like so,

function addFilter($views) {
    // error_log is native php function to log stuff
    // print_r prints human-readable information about a variable, 
    // print_r second parameter makes the function return result instead of echoing it
    error_log( print_r( $views, true ) );
    return $views;
}

Answer 2

The views_edit-page filter returns an array of strings. By default this will be something like this:

array (
  'all' => '<a href="edit.php?post_type=page" class="current" aria-current="page">All <span class="count">(1)</span></a>',
  'publish' => '<a href="edit.php?post_status=publish&#038;post_type=page">Published <span class="count">(1)</span></a>'
)