Using has_tag() outside loop

Question

I want to if the check next post has a specific tag. I tried the following code, but it is not working because has_tag() only works in the loop. I want to use it outside the loop.

<?php if ( has_tag( 'mario', $post->ID ) ) : ?>
my content
<?php endif; ?>

The following code lists the tags from post, but I don't know how to make it work with an if() / else() condition:

global $post;
foreach ( get_the_tags( $post->ID ) as $tag ) {
    echo $tag->name . ', ';
}

Answer 1

The has_tag() conditional does not have to be used inside the Loop; it can be passed a $post object as a second parameter:

has_tag( $tag, $post );

Since has_tag() defaults to the current post, you simply need to pass it the object for the next adjacent post. Fortunately, WordPress provides a function to retrieve adjacent posts: get_adjacent_post():

get_adjacent_post( $in_same_cat, $excluded_categories, $previous );

The $in_same_cat parameter defaults to false, the $excluded_categories parameter defaults to '', and the $previous parameter defaults to true. So, we just need to change that third parameter to false, to retrieve the next post, instead of the previous post:

get_adjacent_post( false, '', true );

Combining it with your has_tag() conditional:

if ( has_tag( 'mario', get_adjacent_post( false, '', true ) ) {
    // Next post has the 'mario' post tag;
    // do something
}

Answer 2

You should be able to use something like this:

$post_id = 123;
$posttags = get_the_tags($post_id);
if (!is_wp_error($posttags) && $posttags) {
    foreach($posttags as $tag) {
        if ($tag->name == 'mario') {
            echo 'yup';
        }
    }
}

What you're doing is:

• Grabbing the tags
• If there are any tags, running each of them through a foreach
• If one of those foreach instances match the case of mario, doing something (in this case, echoing 'yup')

Let me know if that helps.