Single.php not loading when permalink only contains date information

Question

I'm creating a website for a photo project where the artist took photos and did interviews every day of the year. As such, I'd like to keep the URL structure for posts as simple as possible -- meaning mysite.com/month/day, or photoproject.com/12/5.

When I set my posts permalinks to /%monthnum%/%day%, the links are generated correctly, but index.php is used to serve the posts instead of single.php. If I change the permalinks to include other more "unique" information, such as the post title, then single.php is used.

I'm assuming this has something to do with the fact that as far as wordpress is concerned, my URL format is not unique enough per post. Anybody have a solution/workaround?

EDIT: As the comments below outlined, my URLs are obviously being interpreted as date archives and displayed as such. In this case, my question might be "is there a way to tell wordpress not to interpret these as date archives?"

Answer 1

You could force WP's hand here with a filter and action. Doing this doesn't give me the warm fuzzies- I haven't really tested it, so it may have unintended side-effects. Maybe there's a better way to do this.

The first step (after setting permalinks to /%monthnum%/%day%/) is to hook parse_query and test for requests where monthnum and day are set. When that's true, we unset some things and set some other things, to trick WP into thinking this is a singular post request. Maybe this will break other date archives, I didn't test that!

function wpd_parse_query( $query ){
    if( isset( $query->query_vars['monthnum'] )
     && isset( $query->query_vars['day'] )
     && 0 != $query->query_vars['monthnum'] ){
        unset($query->is_archive);
        unset($query->is_date);
        unset($query->is_day);
        $query->is_single = 1;
        $query->is_singular = 1;
    }
}
add_action( 'parse_query', 'wpd_parse_query' );

The next step is to filter post_limits, and test for the unusual condition of it being a singular post with non-zero monthnum. In this case we set it to return the first post, in the case that there's more than one.

function wpd_post_limits( $limit, $query ) {
    if( $query->is_main_query()
     && $query->is_singular()
     && isset( $query->query_vars['monthnum'] )
     && 0 != $query->query_vars['monthnum'] ){
        return 'LIMIT 1';
    }
    return $limit;
}
add_filter( 'post_limits', 'wpd_post_limits', 10, 2 );

You could just leave that part out if you don't care about that case- if the template uses The Loop, it will just repeat the contained markup for each post, though all other data outside the loop will refer to the first post- title, shortlink, body classes, etc..

Now these requests should be interpreted as singular posts, template tags should behave accordingly, and the single template will be loaded.