Attachments are a special post type that holds information about a file uploaded through the WordPress media upload system, such as its description and name, which can display through several post type – attachment template files.

For images, as an example, the attachment post type links to metadata information, about the size of the images, the thumbnails generated, the location of the image files, the HTML alt text, and even information obtained from EXIF data embedded in the images.

As shown in the template hierarchy, you are able to display your attachments through several template files in order of fallback:

1. MIME_type.php and a subtype.php
   It can be any MIME type (For example: image.php, video.php, application.php). For text/plain, the following path is used (in order):
   1. text_plain.php
   2. plain.php
   3. text.php
2. attachment.php
3. single-attachment.php
4. single.php
5. singular.php
6. index.php

MIME_type.php

Attachments are served by template files based on their mime-type. As an example, if your attachment is an image, your can customize how they display through the creation of an image.php template file. All images with the post_mime_type of image/* will render though your image.php template file.

Attachments also support the use of a mime subtype.php file. To continue with the image example, you can further customize your theme to support not only an image.php file but a jpg.php subtype file.

Attachment.php

An attachment page (attachment.php) is a single post page with the post type of attachment, generated through the creation of an attachment.php. Just like a single post page, which is dedicated to your article, the attachment page provides a dedicated page in attachments in your theme.

Creation of attachment page is as simple as creating an attachment.php file. The attachment.php file then contains code similar to the single.php post page.

<div class="entry-attachment">
	<?php
	$image_size = apply_filters( 'wporg_attachment_size', 'large' );
	echo wp_get_attachment_image( get_the_ID(), $image_size );
	?>

	<?php if ( has_excerpt() ) : ?>
		<div class="entry-caption">
			<?php the_excerpt(); ?>
		</div><!-- .entry-caption -->
	<?php endif; ?>
</div><!-- .entry-attachment -->

Function Reference

• get_attachment_template() : Retrieve path of attachment template in current or parent template.