To show the ‘featured image’ of the top post as header image in an archive page in the Twenty Eleven theme, edit header.php in the child theme;
change this section:
<?php
/*
* The header image.
* Check if this is a post or page, if it has a thumbnail, and if it's a big one
*/
if ( is_singular() && has_post_thumbnail( $post->ID ) &&
( /* $src, $width, $height */ $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), array( $header_image_width, $header_image_width ) ) ) &&
$image[1] >= $header_image_width ) :
// Houston, we have a new header image!
echo get_the_post_thumbnail( $post->ID, 'post-thumbnail' );
else :
// Compatibility with versions of WordPress prior to 3.4.
if ( function_exists( 'get_custom_header' ) ) {
$header_image_width = get_custom_header()->width;
$header_image_height = get_custom_header()->height;
} else {
$header_image_width = HEADER_IMAGE_WIDTH;
$header_image_height = HEADER_IMAGE_HEIGHT;
}
?>
<img src="<?php header_image(); ?>" width="<?php echo $header_image_width; ?>" height="<?php echo $header_image_height; ?>" alt="" />
<?php endif; // end check for featured image or standard header ?>
to:
<?php
/*
* The header image.
* Check if this is an archive and if the latest post has a thumbnail, and if it's a big one
* or Check if this is a post or page, if it has a thumbnail, and if it's a big one
*/
if ( is_archive() ) :
the_post();
$archive_thumb = '';
if( has_post_thumbnail( $post->ID ) &&
( /* $src, $width, $height */ $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), array( $header_image_width, $header_image_width ) ) ) &&
$image[1] >= $header_image_width ) :
$archive_thumb = get_the_post_thumbnail( $post->ID, 'post-thumbnail' );
endif;
rewind_posts();
endif;
if ( is_archive() && $archive_thumb ) :
echo $archive_thumb; //the featured image of the latest post in the archive
elseif ( is_singular() && has_post_thumbnail( $post->ID ) &&
( /* $src, $width, $height */ $image = wp_get_attachment_image_src( get_post_thumbnail_id( $post->ID ), array( $header_image_width, $header_image_width ) ) ) &&
$image[1] >= $header_image_width ) :
// Houston, we have a new header image!
echo get_the_post_thumbnail( $post->ID, 'post-thumbnail' );
else :
// Compatibility with versions of WordPress prior to 3.4.
if ( function_exists( 'get_custom_header' ) ) {
$header_image_width = get_custom_header()->width;
$header_image_height = get_custom_header()->height;
} else {
$header_image_width = HEADER_IMAGE_WIDTH;
$header_image_height = HEADER_IMAGE_HEIGHT;
}
?>
<img src="<?php header_image(); ?>" width="<?php echo $header_image_width; ?>" height="<?php echo $header_image_height; ?>" alt="" />
<?php endif; // end check for featured image or standard header ?>
