WordPress PHP - 如何按特定的“meta_key”值对类别/归档结果进行排序？

Question

I previously made a post here: How do I sort by a custom field without manually creating a new page?

However, I believe I asked the wrong question (and I may still be asking the wrong question). Actually think I may need a complex query that will display posts ordered by a meta value. The site is using a theme called "AgentPress". I believe passing params via the URL bar may be too simplistic for what I need.

Honestly I like the way the current category pages display (formatting, etc.), I simply need to "short-circuit" the process so that any category/archive page is sorted by the meta_key for the "property price" as opposed to the date of entry. If there is a simple, more "WordPress-y" mechanism for doing this, I'm all ears. Please be explicit about where to place the code, etc.

FYI, at this point it's clear that passing "order=ASC" and "order=DESC" in the URL works. However, it seems that nothing I do with "meta_key" or anything related has any effect.

Thanks in advance.

Answer 1

You can add a filter on pre_get_posts hook.

Put this code in functions.php (in your theme dir) :

add_filter('pre_get_posts', 'pre_get_posts_hook' );

function pre_get_posts_hook($wp_query) {
    if (is_category() || is_archive())
    {
        $wp_query->set( 'orderby', 'meta_value_num' );
        $wp_query->set( 'meta_key', 'price' );
        $wp_query->set( 'order', 'ASC' );
        return $wp_query;
    }
}

You can use meta_value instead of meta_value_num (available with v2.8), but I assume that price is a numeric value.