This Q is a follow up to this answer on the Q: “How to exclude a specific term for the search?”.
4 ways to filter out posts that have a specific term
Type | Pro | Contra
--------------------------------------------------------
Run a new query | Easy to implement | Add. Queries
| Add. time to execute the DB call + processing the parsing of the results
Inside the loop | Easy to implement | Sometimes Add. Queries
| Add. time to execute
Modify the query | Full control | Hard to implement
| Needs a lot of knowledge (preparing, DB interaction)
Add new query parts | No perform. impact | Hard to get around
| Secure
| Full core support
The first type imho is not an option. The “Types” 2 & 3 are already answered in the other Q and both still have some backdraws.
Question:
- How to add an additional
tax_query
argument to the main query using (for e.g.) thepre_get_posts
filter? - Do you know additional ways to modify the main query?
1 Answer
You can set the taxonomy query for the main query using pre_get_posts:
add_action( 'pre_get_posts', 'my_exclude_terms_from_query' );
function my_exclude_terms_from_query( $query ) {
if ( $query->is_main_query() /* && whatever else */ ) {
$tax_query = array (
array(
'taxonomy' => 'category',
'terms' => array( 'cat-slug' ),
'field' => 'slug',
'operator' => 'NOT IN',
)
);
$query->set( 'tax_query', $tax_query );
}
}
If tax_query
is already set and you need to modify it instead, you can grab and then add to the $tax_query
array.