Display a custom field rating system in the front end

Question

I have added a content rating system to my platform where the authors can select which audience their post is appropriate for. Currently, these options are available:

Unrated

G

PG

R

The code that I use to display the rating options on the post edit page is:

// Article Content Rating
add_action( 'add_meta_boxes', 'rating_select_box' );
function rating_select_box() {
    add_meta_box(
        'rating_select_box', // id, used as the html id att
        __( 'Content Rating (optional)' ), // meta box title
        'rating_select_cb', // callback function, spits out the content
        'post', // post type or page. This adds to posts only
        'side', // context, where on the screen
        'low' // priority, where should this go in the context
    );

}

function rating_select_cb( $post ) {
    global $wpdb;
    $value = get_post_meta($post->ID, 'rating', true);
    echo '<div class="misc-pub-section misc-pub-section-last"><span id="timestamp"><label>Article Content Rating: </label>';

    $ratings = array(
        1 => ' G ',
        2 => ' PG ',
        3 => ' R ',
    );

    echo '<select name="rating">';
    echo '<option value=""' . ((($value == '') || !isset($ratings[$value])) ? ' selected="selected"' : '') . '> Unrated </option>';

    // output each rating as an option
    foreach ($ratings as $id => $text) {
        echo '<option value="' . $id . '"' . (($value == $id) ? ' selected="selected"' : '') . '">' . $text. '</option>';
    }
    echo '</select>';

    echo '</span></div>';
}

add_action( 'save_post', 'save_metadata');

function save_metadata($postid)
{   
    if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE ) return false;
    if ( !current_user_can( 'edit_page', $postid ) ) return false;
    if( empty($postid) ) return false;


    if ( is_null($_REQUEST["rating"]) ) {
        delete_post_meta($postid, 'rating');
    } else {
        update_post_meta($postid, 'rating', $_REQUEST['rating']);
    }

}
// END Article Content Rating

Now, the problem is, what code do I add to single.php to display their choice? So for instance, if the author selected PG, then I want to echo 'Content Rating: PG'; or if it was on default (unrated), I want to echo 'Content Rating: Unrated';. How is this possible? Ideally, a solution that is light on the server as my platform is heavily trafficked.

Answer 1

You are already doing what you need to do, but in another context.

$value = get_post_meta($post->ID, 'rating', true);

Take that value and format it for display.

Edit: I installed your whole block of code. You are storing you key, not your ratings value. You need to access that $ratings array again to pull the value.

$ratings = array(
    1 => ' G ',
    2 => ' PG ',
    3 => ' R ',
);

if (!empty($ratings[$value])) {
  echo '<p>Content Rating : '.$ratings[$value].'</p>';
} else {
  echo '<p>Content Rating : Unrated</p>';
}

However, even before I spotted the problem I was seeing content echo. "Content Rating: 1" instead of "Content Rating: G". I don't know why you claim to see nothing. If you still see nothing, something is wrong but not with this code.

I made no changes to your original block of code.

Answer 2

Inspecting the meta data (var_dump or FirePHP), we can see that the meta is stored as an associative array with one pair of $key=>$value.

The key is always 0 and the value, the number of the selected rating.
E.g.: array('0'=>'1') for G.

So, this little function returns the correct rating:

function wpse_78113_get_rating( $pid )
{
    $ratings = array(
        1 => ' G ',
        2 => ' PG ',
        3 => ' R ',
    );
    $meta = get_post_meta( $pid, 'rating' );
        // var_dump($meta);

    if( empty($meta) || empty($meta[0]) )
        return 'Content rating: Unrated';

    return 'Content rating: ' . $ratings[$meta[0]];
}

And use it like: echo wpse_78113_get_rating( $post->ID );

Answer 3

if ( is_null($_REQUEST["rating"]) ) {
    delete_post_meta($postid, 'rating');
} else {
    update_post_meta($postid, 'rating', $_REQUEST['rating']);
}

Does this not need to be $post->ID in the save_meta function?