Prevent pre_get_posts filter on specific post type

Question

I am running into one issue with pre_get_post filter.

Actually I have 4 post types. Post, Pages, Events, and Venue. I created one custom field called city for event and venue post type.

When creating custom field I have one option to select post type on which I want to display that custom field.

Now, on the front end part I added one filter on pre_get_posts and modified the main query to get all posts from specific city.

All things are working perfectly on events and venue listing and single page but this filter also applies on post and pages as well.

What I want is, **I want to remove the this filter from the post type which are not included with that custom field.

I have tried with $wp_query->query_vars['page_id'] this code but its not working any more.

Can any one help me to sort this our ?

FYI: My code looks like,

add_action( 'pre_get_posts', 'citywise_post_filter' );
function citywise_post_filter($query) {
    global $wp_query;
    if( isset( $_REQUEST['city_filter'] ) ){
        $city = $_REQUEST['city_filter'];
    }else{
        $city = $_SESSION['CURR_CITY'];
    }
    if ( !is_admin() ){
        $query->set( 'meta_key', '_ct_selectbox_52f65ae267764' );
        $query->set( 'meta_value', $city );
        return;
    }
}

Thanks, Aezaz

Answer 1

Improve your conditional to include a check for post type being queried. It can be done via WP_Query::get method

So, where you have

if ( !is_admin() ){
    $query->set( 'meta_key', '_ct_selectbox_52f65ae267764' );
    $query->set( 'meta_value', $city );
    return;
} 

replace with

if ( ! is_admin() && in_array ( $query->get('post_type'), array('event','venue') ) ) {
    $query->set( 'meta_key', '_ct_selectbox_52f65ae267764' );
    $query->set( 'meta_value', $city );
    return;
}

Also note that using this code, as @offroff noted in his answer, the filter will apply to all queries, the ones you triggered visiting a page (main query) and the ones being triggered via code, using new WP_Query ($args) (secondary queries).

To make the code filter not affect secondary queries, add a check for $query->is_main_query(), so the code becomes:

if ( is_admin() || ! $query->is_main_query() ) return;

if ( in_array ( $query->get('post_type'), array('event','venue') ) ) {
    $query->set( 'meta_key', '_ct_selectbox_52f65ae267764' );
    $query->set( 'meta_value', $city );
    return;
}

Answer 2

Wordpress has a great page about conditional tags

Along with !is_admin() you might wanna do && $query->is_main_query()

In the top of your function you can do if(is_single() || is_page()) {return;} if you don't want the filter to apply on those pages.

Other conditionals u might be able to use is is_post_type_archive('event') && is_post_type_archive('venue')

Edit: Not sure I understand your problem but now I figured this might help you:

$query->set('post_type',array('event','venue'));