WordPress – Setting a default 'featured image' for each Catergory

It looks to me like the problem is that you’re using too many conditionals, which end up giving you unpredictable results. I like to keep things simple. Maybe something like this:

function default_category_featured_image() {
  global $post;
  $category = get_the_category($post->ID);
  switch ($category) {
    case '2':
      set_post_thumbnail($post->ID, '112');
    break;
    case '3':
      set_post_thumbnail($post->ID, '115');
    break;
    case '4':
      set_post_thumbnail($post->ID, '113');
    break;
    case '8':
      set_post_thumbnail($post->ID, '114');
    break;
    default:
      set_post_thumbnail($post->ID, '0');
  }
}
add_action('the_post', 'default_category_featured_image');

Thanks linux4me2 – I’ve just updated my functions.php to your post but I’m still having the same problem, no idea what’s going on. Any other suggestions?

Hmmm…

Are the posts that are giving you weird results in more than one category?

I’ve set the featured image manually as the WordPress one for now which works, I’ve left one of the WordPress category unset that is still not working which is the following post; ‘Web-Tricks Top 10 Best Plugins for WordPress’

There are two posts that have the category ‘WordPress’ and are not working, one has the following:-

Categories: WordPress
Tags: Plugins, WordPress

The other has these:-

Categories: WordPress
Tags: WordPress

Yet theres another post with the same categories/tags as above, and its working.

It’s pretty random. I thought initially it was the posts that had images within the post as all the others that are working don’t have images, I tried removing them and this didn’t resolve it.

Try this instead:

function default_category_featured_image() {
  global $post;
  $category = get_the_category($post->ID);
  switch ($category[0]->term_id) {
    case '2':
      set_post_thumbnail($post->ID, '112');
    break;
    case '3':
      set_post_thumbnail($post->ID, '115');
    break;
    case '4':
      set_post_thumbnail($post->ID, '113');
    break;
    case '8':
      set_post_thumbnail($post->ID, '114');
    break;
    default:
      set_post_thumbnail($post->ID, '0');
  }
}
add_action('the_post', 'default_category_featured_image');

Updated to the above, unfortunately it’s still the same ?? – is it possible to use something like $post-> ‘name’ i.e. ‘WordPress’

I changed the code a little by editing it above and you may have missed my changes, make sure you’re using this line:

switch ($category[0]->term_id) {

It’s better to use the IDs if you can, in case you change the category names down the line.

Make sure you don’t have two “WordPress” categories set up. That would cause this problem because each would have a different ID.

To troubleshoot this, it may be necessary to output the category for each article so you can see why you’re getting odd results.

The other thing that may be tripping us up is multiple categories. I’m just checking the first one in that code. If a post is assigned to more than one, which doesn’t appear to be the case, the code could fail.

linux4me2 – I copied and replaced the whole code you posted.

I went into permalinks and changed it to show the post ID, and when I click on ‘WordPress’ for the none-working posts it does say ID = 3.

I’ve also checked Posts –> Categories, and there is definitely only one Category called ‘WordPress’

All posts only have 1 defined Category, some have 1 or 2 tags.

I’ll try making a new post with the same content and see if that works.

Just to add, I’ve just added 3 posts with ‘WordPress’ as the category, one which was copied, one without the image, and one with just a title and one word as the post. All 3 posts with just ‘WordPress’ as the category are not displaying any image. I’m really unsure as to why this is not working now.

Take a look here; https://web-tricks.co.uk/?cat=3

You can see they are all in the same category, some showing featured image, some not.

Okay I have no idea why that wasn’t working but I installed the following plugin; ‘Default Thumbnail Plus’

You can set a default image if there is no featured image set, and set an image for each category within the control panel. This appears to have fixed the problem and I guess this way it is easier to manage.

I am stuck too. I wonder if it would have worked had you put it in the loop instead of in the functions.php? If you do end up figuring out what was wrong, please post so I know too.