How can I change get_the_post_thumbnail to make 100% width image?

Question

I have a WP site whose center column is variable width.

I would like the featured image to appear front and center - 100% width. If I hard code the image path using a plain old image tag with width=100% it looks exactly as I want.

For obvious reasons I don't want it hard coded.

I'm currently using this but the image goes outside of the bounds of the column.

<?php echo get_the_post_thumbnail($id, 'full', array('class' => 'aligncenter')); ?>

So, my question is this.

How can I mimic the behavior of <img src="myimage.png" width="100%" /> but with the get_the_post_thumbnail convention.

Answer 1

I ended up using the following to solve my problem.

<?php $image_id = get_post_thumbnail_id(); ?>
<?php $image_attributes = wp_get_attachment_image_src( $image_id, 'full');  ?>
<img src="<?php echo $image_attributes[0]; ?>" width="100%">

Answer 2

get_the_post_thumbnail() has multiple filters. Just make use of them from within your functions.php file to catch them all:

$size = apply_filters( 'post_thumbnail_size', $size );
do_action( 'end_fetch_post_thumbnail_html', $post_id, $post_thumbnail_id, $size );
return apply_filters( 'post_thumbnail_html', $html, $post_id, $post_thumbnail_id, $size, $attr );

Else you can still go with my »Dynamic image resize« plugin.