Specific featured image for each category

Question

I´d like to set specific featured image for all posts in one category.

So, if I have category Good Jokes, all posts in category Good Jokes will have the same featured image displayed in front page.

My current code in content.php is:

<?php if(trim(get_the_post_thumbnail($post->ID)) != '' and $themolio_options['show_featured']): ?>
<div class="entry-thumb">
    <a href="<?php the_permalink(); ?>">
    <?php the_post_thumbnail('themolio-featured-image');?>
    </a>
</div>
<?php endif; ?>

Can anybody help?

Answer 1

<?php
if(has_post_thumbnail())
    the_post_thumbnail('themolio-featured-image');
else
    echo wp_get_attachment_image($attachment_id, 'themolio-featured-image');
?>

The above code displays the featured image if the post has one, otherwise the image define by $attachment_id.

I don't know how you're deciding which category term should display which image & what to do in case of multiple categories, so the part where you initialize $attachment_id is left to you.

UPDATE

This code does exactly what you said in your comment. In case of multiple categories, this code will just take the first one.

<?php
$category = get_the_category();
if(!empty($category) && $themolio_options['show_featured']): ?>
<div class="entry-thumb">
    <a href="<?php the_permalink(); ?>">
    <img src="http://example.com/<?php echo $category[0]->term_id;?>.jpg" alt="<?php echo $category[0]->name;?>" />
    </a>
</div>
<?php endif; ?>

Answer 2

Use FPW Category Thumbnails plugin. It does exactly what you need and no coding is required. Map images to their respective categories. If you have many posts already use Apply Mapping button and all posts belonging to the category which has an image mapped to it will get this image as a thumbnail. From this point on everything is automated. When you create or edit a post it will get its thumbnail according to the plugin's mapping on save. As an author of this plugin I'm sure you will not be disappointed!