WordPress Multiple Category Search

From few months I am digging into wordpress for multiple category search options, and finally came up with this.

I just found that wordpress allows multiple tags, which means that if in your URL you type this

http://yourblog.com/tag/tag1+tag2

then it will return all your posts with having tags, tag1 AND tag2

but if you type

http://yourblog.com/tag/tag1,tag2

then it will return all the posts having tag1 OR tag2

Same thing now works for categories also

http://yourblog.com/category/cat1+cat2 and http://yourblog.com/category/cat1,cat2

But this only works for category and tags, I am trying it for search option.

Till now I coded where this URL is working(which means it will search HTML only in the category id 114),

http://yourblog.com/?s=html&cat=114

In this URL, the comma separator works very well, but not the +

I mean to say

http://yourblog.com/?s=html&cat=114,115

works very well but

http://yourblog.com/?s=html&cat=114+115

doesn’t works.

Can anyone help me in this? I really want this to work

Still awaiting

The problem is that in a url the ‘+’ sign is equivalent to a space so that’s how PHP sees it.

If you use an action on parse_request you can make this work like so:

add_action( 'parse_request', 'category_search_logic', 11 );
function category_search_logic( $query ) {

    if ( ! isset( $query->query_vars[ 'cat' ] ) )
        return $query;

    // split cat query on a space to get IDs separated by '+' in URL
    $cats = explode( ' ', $query->query_vars[ 'cat' ] );

    if ( count( $cats ) > 1 ) {
        unset( $query->query_vars[ 'cat' ] );
        $query->query_vars[ 'category__and' ] = $cats;
    }

    return $query;
}

The above will get category ids passed in with ‘+’ in between them by splitting them on a space which is what PHP sees in the $_GET parameter.

If we have more than one item in the array it must be an ‘and’ style search so we can pass the array from splitting on the space into the 'category__and' query var which returns posts in all the specified categories.