Embed content template — renders a post’s content within an oEmbed iframe.

Source: wp-includes/theme-compat/embed-content.php
Since: 4.5.0
Subpackage: Theme_Compat

Purpose

Loaded by get_template_part( 'embed', 'content' ) when the active theme has no embed-content.php. This is the main content template for embedded posts.

Behavior

1. Wrapper

Opens <div> with post_class( 'wp-embed' ).

2. Thumbnail Resolution

Determines a thumbnail image to display:

• If has_post_thumbnail(): uses get_post_thumbnail_id().
• If post type is 'attachment' and wp_attachment_is_image(): uses get_the_ID().
• The thumbnail ID is passed through the embed_thumbnail_id filter.

If a thumbnail ID is found:

• Retrieves attachment metadata via wp_get_attachment_metadata().
• Iterates through $meta['sizes'] to find the size with the widest aspect ratio (width / height). Starts with aspect ratio 1 and measurements [1, 1], fallback image size 'full'.
• The chosen size is passed through the embed_thumbnail_image_size filter.
• Determines shape: if width / height >= 1.75, shape is 'rectangular'; otherwise 'square'.
• The shape is passed through the embed_thumbnail_image_shape filter.

3. Rectangular Thumbnail (Above Title)

If thumbnail exists and shape is 'rectangular':

• Outputs <div class="wp-embed-featured-image rectangular"> containing a link (the_permalink(), target="_top") wrapping wp_get_attachment_image().

4. Post Title

Outputs <p class="wp-embed-heading"> with a link (the_permalink(), target="_top") containing the_title().

5. Square Thumbnail (After Title)

If thumbnail exists and shape is 'square':

• Outputs <div class="wp-embed-featured-image square"> with the same link/image pattern.

6. Excerpt

Outputs <div class="wp-embed-excerpt"> with the_excerpt_embed().

7. embed_content Action

Fires after the excerpt. Documented here with @since 4.4.0.

8. Footer

Outputs <div class="wp-embed-footer"> containing:

• the_embed_site_title() — site icon and name
• <div class="wp-embed-meta"> containing the embed_content_meta action

9. Closes wrapper div.

Hooks

embed_thumbnail_id (filter)

$thumbnail_id = apply_filters( 'embed_thumbnail_id', $thumbnail_id );

Filters the thumbnail image ID for use in the embed template.

Since: 4.9.0
Parameter: int|false $thumbnail_id — Attachment ID, or false if none.

embed_thumbnail_image_size (filter)

$image_size = apply_filters( 'embed_thumbnail_image_size', $image_size, $thumbnail_id );

Filters the thumbnail image size for the embed template.

Since: 4.4.0 (added $thumbnail_id in 4.5.0)
Parameters:

• string $image_size — Thumbnail image size slug.
• int $thumbnail_id — Attachment ID.

embed_thumbnail_image_shape (filter)

$shape = apply_filters( 'embed_thumbnail_image_shape', $shape, $thumbnail_id );

Filters the thumbnail shape. Rectangular images appear above the title; square images appear next to the content.

Since: 4.4.0 (added $thumbnail_id in 4.5.0)
Parameters:

• string $shape — Either 'rectangular' or 'square'.
• int $thumbnail_id — Attachment ID.

embed_content (action)

do_action( 'embed_content' );

Prints additional content after the embed excerpt.

Since: 4.4.0

embed_content_meta (action)

do_action( 'embed_content_meta' );

Prints additional meta content in the embed template footer.

Since: 4.4.0

Functions Called