extend wordpress search query - search

Question

I have a working search query with offset and post_per_page (the user can go through pages)
$args = array(
'post_type' => 'type',
's'=>$the_str,
'posts_per_page' => $the_count,
'offset' => ($the_count*$the_c_page )-$the_count
);
$the_query = new WP_Query( $args );
It works great.
But now I need to add a meta field to the search function. It should get all post where s=>$query OR meta-field=>$query
Something like this:
$args = array(
'post_type' => 'type',
'posts_per_page' => $the_count,
'offset' => ($the_count*$the_c_page )-$the_count,
'meta_query' => array(
'relation' => 'OR',
's'=>$the_str,
array(
'key' => 'key',
'value' => $the_str
)
);
$the_query = new WP_Query( $args );
Unfortunately this will only search after the second condition. Does anybody have an idea?

Answer 1

If you crack open query.php you'll see that it really isn't built with this in mind. It isn't that it isn't a great idea, it's just that each individual query part is concatenated onto the main WHERE using an AND. So "title contains XYZ" AND "whatever the meta query is" AND "whatever the tax query is", etc. Meta and Tax both have sub logic within them that supports AND and OR but there's no way to perform this between these outer parts.
However, you might be able to do what you're looking for by tapping into one of the filters, possibly get_meta_sql. The meta query returns a statement that puts in the AND that you want to be an OR so you can just look for that and replace it:
function change_and_to_or_for_meta( $meta_query, $type, $primary_table, $primary_id_column, $context )
{
if( 0 === strpos( $meta_query['where'], ' AND' ) )
{
$meta_query['where'] = ' OR' . substr( $meta_query['where'], 4 );
}
return $meta_query;
}
//Add our filter to replace the AND at the start with OR
add_filter( 'get_meta_sql', 'change_and_to_or_for_meta', 10, 5 );
$query = new WP_Query( $args );
//Remove our filter so we don't mess other things up
remove_filter( 'get_meta_sql', 'change_and_to_or_for_meta', 10 );