using custom fields on content.php file of my theme

Question

is there any error in following code? when i use following code in content.php file of my theme, then nothing is displayed on blog, it seems there is some error. and when i comment folowing code everything gets back to normal.

<?php if (empty(get_custom_field_value("signature",""))) : ?>
    &mdash;
    <?php the_category( '<span>/</span>' ); ?>      
<?php endif; ?>

here is get_custom_field_value function:

function get_custom_field_value($szKey, $prefix = '', $bPrint = false) {
    global $post;
    $szValue = get_post_meta($post->ID, $szKey, true);
    if ( $bPrint == false ) return (empty($szValue) ? "" : $prefix . $szValue); else echo (empty($szValue) ? $szValue : $prefix . $szValue);
}

Answer 1

empty will only take variables passed by reference. so empty(some_function()) will never work. See the php docs for more information.

<?php if (get_custom_field_value("signature","")) : ?>
    &mdash;
    <?php the_category( '<span>/</span>' ); ?>      
<?php endif; ?>

You're better off just checking for the boolean, like above. The get_custom_field_value function already takes care of making sure you get something back.

On a side note: you should prefix your function names. get_custom_field_value is very generic. yourtheme_get_custom_field_value (replacing "yourtheme" with the theme name) has less of a chance of conflicting with other function names.