Grow your CSS skills. Land your dream job.

Last updated on:

If Page Is Parent or Child

There are built in conditional WordPress functions for testing for a page:

if ( is_page(2) ) {
  // stuff
}

Or for testing if a page is a child of a certain page:

if ( $post->post_parent == '2' ) {
  // stuff
}

But there is no built in function that combines these two things, which is a fairly common need. For example, loading a special CSS page for a whole "branch" of content. Like a "videos" page and all its children individual videos pages.

This function (add to functions.php file) creates new logical function to be used in this way:

function is_tree($pid) {      // $pid = The ID of the page we're looking for pages underneath
	global $post;         // load details about this page
	if(is_page()&&($post->post_parent==$pid||is_page($pid))) 
               return true;   // we're at the page or at a sub page
	else 
               return false;  // we're elsewhere
};

Usage

if (is_tree(2)) {
   // stuff
}

Comments

  1. Paul
    Permalink to comment#

    Hey,

    how can I make it work with categories?

    if I just replace ‘is_page’ with ‘is_category’ it is true for the category overview but not for alle the articles in it..

    Paul

  2. Permalink to comment#

    This is good, but it only works one level deep.

    From the WordPress Codex:
    “Note that if you have more than one level of pages the parent page is the one directly above and not the one at the very top of the hierarchy.”

    See more about this at the WP Codex: Conditional Tags

    P.S.
    I hope noone made a buck out of this snippet, it’s straight from the wordpress codex.

    • Port 80
      Permalink to comment#

      NB I had this problem ‘only works one level deep’

      But this function works with all ‘ancestors’ not just single level ‘child’ pages

      also take straight from the WP codex http://codex.wordpress.org/Conditional_Tags function

      function is_tree($pid)
      {
        global $post;
      
        $ancestors = get_post_ancestors($post->$pid);
        $root = count($ancestors) - 1;
        $parent = $ancestors[$root];
      
        if(is_page() && (is_page($pid) || $post->post_parent == $pid || in_array($pid, $ancestors)))
        {
          return true;
        }
        else
        {
          return false;
        }
      };
      
    • Rams
      Permalink to comment#

      Port 80! MAARRRYY MEEEE.

      Thanks.

    • Permalink to comment#

      Port 80 – Thank you!

    • Port 80′s is_tree() function does the trick but will throw a Notice if PHP notices are turned on. As a workaround I added:

      if ( $root < 0) { return false; }

      just after:

      $root = count($ancestors) - 1;

      and just before:

      $parent = $ancestors[$root];

      Haven't done a ton of testing but so far this seems to be working as expected.

    • Well my “greater than” angle bracket got escaped but here’s the idea:

      if ($root [LESS THAN] 0) { return false; }

  3. Nice snippet here!

  4. Brenna
    Permalink to comment#

    How can you use this if you don’t want to specify a certain page ID. I need to be able to check dynamically if any current page I happen to be on is part of a branch (whether it’s the parent or child), and if so, then output a menu depending on whatever page ID it automatically retrieves.

    Any help or suggestions would be appreciated.

  5. Permalink to comment#

    Thanks for this! :)

  6. Thank you! Needed this for my WordPress theme sidebar :)

  7. Cool, thanks so much for posting this! Very useful =)

  8. orangerie

    Just great, thanks !

  9. Permalink to comment#

    Great tutorial! Thanks! I also have another approach on this.

    
    <?php  global $post; 
    if ( is_page('2') || $post->post_parent == '2'){
    	//stuff if page has id of 2 and its subpages
    }
    else {
    	//stuff if not
    }
    ?>
    
    • Permalink to comment#

      i figure it out that the above tutorial is better than my approach. I’m going to use that approach from now on.

  10. Permalink to comment#

    Had to tackle this today and the below worked perfectly for me (works with any nesting level)

    
    if (is_page(27) || in_array(27, $post->ancestors))
    {
       // stuff if your page has ID of 27 or is a subpage (any nested level) of page ID 27
    }
    
    
  11. Hi there,
    I’m just wondering about this coding. I have a website that I’m building where the Parent has Child pages. Eg… I have a Parent page that is called:

    ABOUT US (parent page)
    Company Overview (child page)
    Director (child page)

    The company Overview page is fine because its the same page as about page. But when I click on Director Page I want the Parent Page “ABOUT US” to be highlighted as well. So both pages would be highlighted the child and parent page. The coding I’ve done is really simple. Its as follows

    ABOUT US – nav coding.

    <a class="about_us" href="”

    >

    and DIRECTOR – nav coding.

    <a href="”
    class=”director”>

    Is there a coding where I can say if the parent page we are on is “ABOUT US” to make it show it selected as well? Can you write me an example please

    Thanks in Advance.
    Oh and the link for the website is http://www.fairwayviewapartmentssamoa.com

  12. Thank you tremendously for sharing this. I have come across your site multiple times now while searching for help on various things. Keep it up, and tank you again.

  13. Anyway of making this work by slug?

    I imagine we’d have to get the id from the slug.

    I’m gonna play around some this weekend.

    • Not sure if you ever figured this out, but for those who want to know:

      Add this to functions:

      function is_tree($pid) {
      	global $post;
      	if(is_page()&&($post->post_parent==$slug||is_page($slug)))
                     return true; 
      	else
                     return false;
      };

      In order to make this work for the slug instead of the page ID. And yes, the $pid is needed in the function call, I’m not sure the exact reason but $slug doesn’t work there.

  14. This was exactly what I needed!!!

    I was trying to edit the submenu navigational links on pages based on the child of a parent.

    In a nut shell, when on a child page, I needed the nav menu to reflect the links of the parent of the child not the child itself.

    This tutorial helped to push me in the right direction. Now I can add a custom class to the current page!

  15. Mike Stimson
    Permalink to comment#

    This worked perfectly.

    Thank you very much.

  16. Permalink to comment#

    Hello,
    This is exactly what i need. And the best thing is, your snippet works like a charm! thank you so much :)

  17. Permalink to comment#

    Thanks so much for this! It totally saved my butt

  18. Permalink to comment#

    I use this function on almost every project!

    if (have_problem()) {
    go to css-tricks.com
    }

  19. Permalink to comment#

    This is what i was looking for.

    Thanks.

  20. Great tip.
    Thanks for sharing :)

  21. Permalink to comment#

    Still loving this one (: cheers

  22. Permalink to comment#

    You could do is like this:

    function tree(){
      $class = '';
      if( is_page() ) { 
      global $post;
          /* Get an array of Ancestors and Parents if they exist */
      $parents = get_post_ancestors( $post->ID );
          /* Get the top Level page->ID count base 1, array base 0 so -1 */ 
      $id = ($parents) ? $parents[count($parents)-1]: $post->ID;
         /* Get the parent and set the $class with the page slug (post_name) */
      $parent = get_page( $id );
      $class = $parent->post_name;
    }
    return $class;
    }
    

    and you can cale it this way:

    if(tree()=="myPageSlug1"){ echo" Hello World" }
    

    Now you get an Hello World on every childpage of myPageSlug1

  23. Jay

    Sweet. Saved my butt!

  24. Chris
    Permalink to comment#

    How do you write a function that checks if $post->post_parent is equal to one or another id instead of just a single id?

  25. Mirko y3B4ch
    Permalink to comment#

    Chris, why dont you lock this topic as well. You already closed a shit load of other useful topics.

  26. Cumhur Günay
    Permalink to comment#

    İs there a any code or condition that is check that the current page has a subpage or not. I dont mean that the current page has a parent page or not.

    • Cumhur Günay
      Permalink to comment#

      İ got it :)))

      query(array(‘post_type’ => ‘page’));
      $id = $post->ID;

      $children = get_page_children( $id, $all_wp_pages );
      if($children) {
      echo “Parent”;
      }
      ?>

    • Cumhur Günay
      Permalink to comment#

      Correction of Code.

      query(array(‘post_type’ => ‘page’));?>
      <?php $id = $post->ID;

                  $children = get_page_children( $id, $all_wp_pages ); ?>
                  <?php if($children) { ?>
                      <h1>Parent</h1> 
                  <?php } else { ?>
                      <h1>Child</h1>  
                  <?php } ?>
      
  27. Here’s my direction. Hopefully it’s helpful to someone looking to show both contingent depth and specific subpage content. I’m using the list_pages_at_depth(); plugin here. Looks for children on the second and third levels, then shows some pages.

Leave a Comment

Current day month ye@r *

*May or may not contain any actual "CSS" or "Tricks".