Restricting Post Content Visibility with Custom Code – where to put it?

Question

you can place your function in functions.php and attach an action hook . which will decide when to call your function. If you only want to hide content of the posts you can use this hook

 add_action('the_content', 'yourcustomfunction')

or i would suggest this hook which will be called before your actually post query is run .

add_action('pre_get_posts', 'yourcustomfunction') 

function yourcustomfunction () {
   // YOUR CUSTOM CODE HERE
}

place this in your theme’s functions.php .