How to check custom fields from functions.php

Question

I'm trying to hide certain menu items based on the custom fields on a page. I could use CSS or a script to hide the items, that's not the problem. What I don't know is how I can check the custom fields (if field empty then hide item) in my functions.php.

Any ideas?

Answer 1

I don't know if you need to hide the element completely, as in "never display it", or if you need to hide it conditionally with JavaScript-- say, to get a toggle effect. Either case is similar and would use get_post_meta().

To conditionally display the data use something like:

$m = get_post_meta(get_the_ID(),'my_meta_key');
if(!empty($m)) {
  echo '<div>your data</div>';
}

If you want something that you can toggle with JavaScript use:

$m = get_post_meta(get_the_ID(),'my_meta_key');
$str = '<div %s>your data</div>';
if(!empty($m)) {
  $str = sprintf($str,'class="'.$m.'"'); 
}
echo $str;