Theme Customizr – Can't display a post list

Hello all,

My problem is fairly common : I would like to display the post list of a specific category on a page under the same style as search results for instance.

To do so, I built a new function in the function.php of my child theme:

add_action(‘__before_loop’, ‘display_list’, 5);

function display_list($query){
if ( ! is_page(‘learn’) ){ //’learn is the slug of my page on which I want to display the post list
return;
}
query_posts(‘post_type=post&cat=3&paged=’. get_query_var(‘paged’));
// 3 is the category ID of the posts I want to display
add_action(‘__after_article_container’, ‘wp_reset_query’, 5);
}

But nothing is dislayed on my page “learn”.

Anyone could help me ?
Thanks a lot,
M.