How do i get post thumbnail using attachment code

Question

Hi i'm using this code below, which links the title of the post to the first attachment in the post. But how do I change it so that it grabs the thumbnail instead?

<?php  
$args = array(
'post_type' => 'attachment',
'numberposts' => -1,
'offset' => 0,
'orderby' => 'menu_order',
'order' => 'asc',
'post_status' => null,
'post_parent' => $post->ID,
);
$attachments = get_posts($args);
if ($attachments) {
foreach ($attachments as $attachment) {
    if(wp_attachment_is_image( $attachment->ID )) {
echo '<a href="'. get_attachment_link($attachment->ID) . '">'. get_the_title() .'</a>';

    break;
   } 
}
}
else {
echo ''. get_the_title() .'';
};
?>

EIDT: Just as the title link goes to the attachment page of the first image, i want the thumbnail to do the same.

so instead of '.get_the_title().'</a>' i want to get the thumbnail attached to the post.

Answer 1

I can't tell if you want a link to the thumbnail or you want the image to be the thumbnail.

To get the image assigned to the post as the thumbnail image, use get_the_post_thumbnail:

  $thumb = get_the_post_thumbnail($post_id, 'thumbnail');

To get the thumbnail using the attachment ID use wp_get_attachment_image:

$thumb = wp_get_attachment_image( $attachment_id, 'thumbnail' )

Not that that will return an empty string if the requested image does not exist.

To get a link to the image using the attachment ID use wp_get_attachment_thumb_url

$thumb = wp_get_attachment_thumb_url( $attachment_id ); 

Or wp_get_attachment_image_src:

$thumb = wp_get_attachment_image_src( $attachment_id, 'thumbnail' ); 
if (!empty($thumb['url'])) {
  $thumb_url = $thumb['url'];
}

Based on a comment below: How to "get the thumbnail of the post and make it link to the first attatchment under that post"

$thumb = get_the_post_thumbnail($post->ID, 'thumbnail');
if (!empty($thumb)) {
  $args = array(
    'post_type' => 'attachment',
    'numberposts' => 1,
    'orderby' => 'menu_order',
    'order' => 'asc',
    'post_status' => 'inherit',
    'post_parent' => $post->ID,
  );
  $attachments = get_posts($args);
  if (!empty($attachments[0]->ID)) {
    if(wp_attachment_is_image( $attachments[0]->ID )) {
      $title = '<a href="'.get_attachment_link($attachments[0]->ID).'">'.$thumb.'</a>';
    } 
  }
}
if (!empty($title)) {
  echo $title;
} else {
  the_title();
}

Answer 2

If you want title to link to post thumbnail instead of first attachment, then something like this should help:

if ( has_post_thumbnail() ) {
    echo '<a href="'. get_attachment_link( get_post_thumbnail_id() ) . '">'. get_the_title() .'</a>';
} else {
    echo get_the_title();  // you don't have to concatenate it with empty strings
}

Answer 3

Just replace:

echo '<a href="'. get_attachment_link($attachment->ID) . '">'. get_the_title() .'</a>';

with:

echo wp_get_attachment_link( $attachment->ID , '', true, false, get_the_post_thumbnail( get_the_ID, 'thumbnail') ) 

You find further information how to customize the output of wp_get_attachment_link() in the codex: http://codex.wordpress.org/Function_Reference/wp_get_attachment_link .

It's always very helpful to check the used function in codex and scroll to the bottom, where you can find related functions: http://codex.wordpress.org/Function_Reference/get_attachment_link#Related

Edit:

There is one small piece you could edit on s_ha_dums solution to make it even more cleaner.

Replacing:

$title = '<a href="'.get_attachment_link($attachments[0]->ID).'">'.$thumb.'</a>';

with:

$title = wp_get_attachment_link( $attachments[0]->ID , '', true, false, $thumb );

would use WordPress' function for getting the attachements link using the post-thumbnail as link.