Question

I was wondering what the filter was to change the search term in WordPress?

For example, if someone types in xxx, how could I change that to yyy before it goes into the wordpress search engine?

Cheers.

Answer 1

Change it when it gets to WordPress, right before WP queries the database:

$search_replacements = array(
    'find' => 'replace',
    'find2' => 'replace2',
    'var' => 'foo'
);
function modify_search_term($request_vars) {
    global $search_replacements;
    if (!empty($request_vars['s']) && !empty($search_replacements[$request_vars['s']])) {
        $request_vars['s'] = $search_replacements[$request_vars['s']];
    }
    return $request_vars;
}
add_filter('request', 'modify_search_term');

This will allow you to handle as many conditions as you can think up and add to the $replacements array.

The 99 in the add_filter is to get it to run late so that you’re the last one to make changes to the query (could be important depending upon what other plugins you have installed).

Your URL will still indicate the original term, but you save a page load. If you have a high traffic site then you don’t want to redirect just to get a pretty url.