How to exclude a specific categogy from a custom page template

Question

I have a custom page template that uses the wordpress loop to display all my posts like usual:

<?php if (have_posts()) : while (have_posts()) : the_post();

There is a category that I don't want to display on this page. The id of this category is 3.

So I though I could use something like this:

<?php if (have_posts()) : while (have_posts()) : the_post();
          if ( in_category('3') ) continue;
               the_content();
          endwhile;
      endif; 
?>

But the posts with this category ID are still displaying.

I've also tried adding this to functions.php:

function exclude_category($query) {
    if (isset($query)) {
        $query->set('cat', '-3');
    }
    return $query;
}
add_filter('pre_get_posts', 'exclude_category');

This works, but it is global to every page on the site (obviously), which is what I don't want. I just want category ID removed from this single page template.

Is it possible to do this?

Answer 1

Did you try:

function exclude_category($query) {
    if ( is_page('slug-of-page') && isset($query) ) {
        $query->set('cat', '-3');
    }
    return $query;
}
add_filter('pre_get_posts', 'exclude_category');