Adding post thumbnails and excerpts to Twenty Eleven theme is not much different than how they would be added to Twenty Ten.
The first step is to create a functions.php file for your child theme if you don’t already have one and add this to it. This adds our own custom size thumbnail of 140px X 140px.
I strongly recommend installing and running Ajax Rebuild Thumbnails plugin after completing this tutorial. It will create a new image size for each featured image. You can uninstall it after it’s finished.
// This sets the dimensions for the thumbnails displayed on the homepage add_image_size('excerpt-thumbnail', 140, 140, true);
The next step we need to tell our theme to display excerpts instead of the full post. Copy content.php to your child theme directory and open it. Find this block of code around line 35
<?php if ( is_search() ) : // Only display Excerpts for Search ?> <div class="entry-summary"> <?php the_excerpt(); ?>
Change it to this.
<?php if ( is_search() | is_home() ) : // Edit this to show excerpts in other areas of the theme?> <div class="entry-summary"> <!-- This adds the post thumbnail/featured image --> <div class="excerpt-thumb"><a href="<?php the_permalink(); ?>" title="<?php printf( esc_attr__( 'Permalink to %s', 'twentyeleven' ), the_title_attribute( 'echo=0' ) ); ?>" rel="bookmark"> <?php the_post_thumbnail('excerpt-thumbnail', 'class=alignleft'); ?></a></div> <?php the_excerpt(); ?>
By adding | is_home() to the if statement it tells our theme to display excerpts on the homepage. I find doing it this way allows more control over which areas display excerpts and which display the full post.
Just below that you can see we’ve added the post thumbnail, the size of this is controlled by what we added to functions.php in the first step.
Now just save those two files and add a featured image to your posts and you’ll see post thumbnails with excerpts.