How to exclude posts of a certain format from the feed

Question

I want to exclude posts from aside post-format in the feed. I have already checked up here about how to exclude posts from a certain post format from the loop but how to exclude posts from a post format in the feed? Couldn't modify it because I am not very good with the code.

Answer 1

If you want to modify the feed, you should hook into the main query that WordPress will do on every page request. The best hook here is pre_get_posts. This code example will hook into pre_get_posts, check whether it is a feed, and add the post format taxonomy query:

add_action( 'pre_get_posts', 'wpse18412_pre_get_posts' );
function wpse18412_pre_get_posts( &$wp_query )
{
    if ( $wp_query->is_feed() ) {
        $post_format_tax_query = array(
            'taxonomy' => 'post_format',
            'field' => 'slug',
            'terms' => 'post-format-image', // Change this to the format you want to exclude
            'operator' => 'NOT IN'
        );
        $tax_query = $wp_query->get( 'tax_query' );
        if ( is_array( $tax_query ) ) {
            $tax_query = $tax_query + $post_format_tax_query;
        } else {
            $tax_query = array( $post_format_tax_query );
        }
        $wp_query->set( 'tax_query', $tax_query );
    }
}