Complete reference of hooks related to posts, content, revisions, and featured images.

Post CRUD Hooks

Insertion Hooks (Create)

pre_post_insert

Fires immediately before a new post is inserted.

do_action( 'pre_post_insert', $data );

• $data (array) – Unslashed post data

Since: 6.9.0

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wp_insert_post_empty_content

Filters whether the post should be considered empty.

apply_filters( 'wp_insert_post_empty_content', $maybe_empty, $postarr );

• $maybe_empty (bool) – Whether post is empty
• $postarr (array) – Post data

Return true to prevent insertion.

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wp_insert_post_parent

Filters the post parent (for hierarchy loop prevention).

apply_filters( 'wp_insert_post_parent', $post_parent, $post_id, $new_postarr, $postarr );

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wp_insert_post_data

Filters slashed post data before database insertion.

apply_filters( 'wp_insert_post_data', $data, $postarr, $unsanitized_postarr, $update );

• $data (array) – Slashed, sanitized, processed post data
• $postarr (array) – Sanitized but unprocessed post data
• $unsanitized_postarr (array) – Original unsanitized data
• $update (bool) – Whether updating existing post

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wp_insert_attachment_data

Same as above, but for attachments.

apply_filters( 'wp_insert_attachment_data', $data, $postarr, $unsanitized_postarr, $update );

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wp_insert_post

Fires after a post is saved (create or update).

do_action( 'wp_insert_post', $post_id, $post, $update );

• $post_id (int)
• $post (WP_Post)
• $update (bool)

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save_post_{$post_type}

Fires after a post of specific type is saved.

do_action( "save_post_{$post->post_type}", $post_id, $post, $update );

Examples: save_post_post, save_post_page, save_post_movie

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save_post

Fires after any post is saved.

do_action( 'save_post', $post_id, $post, $update );

Note: This fires for ALL post types including revisions. Check $update and post type if needed.

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wp_after_insert_post

Fires after a post is fully inserted/updated, including terms and meta.

do_action( 'wp_after_insert_post', $post, $update, $post_before );

• $post (WP_Post) – Post object after changes
• $update (bool)
• $post_before (WP_Post|null) – Post before changes (null if new)

Since: 5.6.0 – Preferred over save_post for most uses.

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Update Hooks

pre_post_update

Fires before a post is updated.

do_action( 'pre_post_update', $post_id, $data );

• $post_id (int)
• $data (array) – Unslashed post data

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edit_post_{$post_type}

Fires after a specific post type is updated.

do_action( "edit_post_{$post->post_type}", $post_id, $post );

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edit_post

Fires after any post is updated.

do_action( 'edit_post', $post_id, $post );

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post_updated

Fires after a post is updated (with before/after comparison).

do_action( 'post_updated', $post_id, $post_after, $post_before );

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Delete Hooks

pre_delete_post

Filters whether to proceed with deletion.

apply_filters( 'pre_delete_post', $check, $post, $force_delete );

Return non-null to short-circuit.

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before_delete_post

Fires before a post is deleted.

do_action( 'before_delete_post', $post_id, $post );

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delete_post_{$post_type}

Fires before a specific post type is deleted.

do_action( "delete_post_{$post->post_type}", $post_id, $post );

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delete_post

Fires just before the post is deleted from database.

do_action( 'delete_post', $post_id, $post );

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deleted_post_{$post_type}

Fires after a specific post type is deleted.

do_action( "deleted_post_{$post->post_type}", $post_id, $post );

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deleted_post

Fires after a post is deleted.

do_action( 'deleted_post', $post_id, $post );

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after_delete_post

Fires at the conclusion of wp_delete_post().

do_action( 'after_delete_post', $post_id, $post );

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Trash Hooks

pre_trash_post

Filters whether to proceed with trashing.

apply_filters( 'pre_trash_post', $trash, $post, $previous_status );

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wp_trash_post

Fires before a post is sent to trash.

do_action( 'wp_trash_post', $post_id, $previous_status );

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trashed_post

Fires after a post is trashed.

do_action( 'trashed_post', $post_id, $previous_status );

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pre_untrash_post

Filters whether to proceed with untrashing.

apply_filters( 'pre_untrash_post', $untrash, $post, $previous_status );

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untrash_post

Fires before a post is restored from trash.

do_action( 'untrash_post', $post_id, $previous_status );

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untrashed_post

Fires after a post is restored from trash.

do_action( 'untrashed_post', $post_id, $previous_status );

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wp_untrash_post_status

Filters the status assigned to restored posts.

apply_filters( 'wp_untrash_post_status', $new_status, $post_id, $previous_status );

Default is ‘draft’ (since 5.6.0).

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Post Status Hooks

transition_post_status

Fires when post status changes.

do_action( 'transition_post_status', $new_status, $old_status, $post );

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{$old_status}to{$new_status}

Dynamic hook for specific status transitions.

do_action( "{$old_status}_to_{$new_status}", $post );

Examples:

• draft_to_publish
• pending_to_publish
• publish_to_trash

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{$new_status}_{$post_type}

Fires for specific status and post type.

do_action( "{$new_status}_{$post->post_type}", $post_id, $post );

Examples:

• publish_post
• publish_page
• draft_movie

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Content Display Hooks

the_title

Filters the post title.

apply_filters( 'the_title', $post_title, $post_id );

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protected_title_format

Filters the "Protected: %s" format.

apply_filters( 'protected_title_format', $prepend, $post );

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private_title_format

Filters the "Private: %s" format.

apply_filters( 'private_title_format', $prepend, $post );

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the_content

Filters the post content for display.

apply_filters( 'the_content', $content );

This is a critical filter – many plugins add functionality here (embeds, shortcodes, etc.).

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the_content_more_link

Filters the "read more" link.

apply_filters( 'the_content_more_link', $more_link_element, $more_link_text );

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the_excerpt

Filters the displayed excerpt.

apply_filters( 'the_excerpt', $post_excerpt );

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get_the_excerpt

Filters the retrieved excerpt.

apply_filters( 'get_the_excerpt', $post_excerpt, $post );

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excerpt_length

Filters auto-generated excerpt length (words).

apply_filters( 'excerpt_length', $length );

Default: 55 words

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excerpt_more

Filters the "read more" text for auto-excerpts.

apply_filters( 'excerpt_more', $more );

Default: […]

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the_guid

Filters the post GUID.

apply_filters( 'the_guid', $post_guid, $post_id );

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get_the_guid

Filters the retrieved GUID.

apply_filters( 'get_the_guid', $post_guid, $post_id );

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Post Class Hooks

post_class

Filters the array of post CSS classes.

apply_filters( 'post_class', $classes, $css_class, $post_id );

• $classes (string[]) – Array of class names
• $css_class (string[]) – Additional classes
• $post_id (int)

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post_class_taxonomies

Filters taxonomies used for class generation.

apply_filters( 'post_class_taxonomies', $taxonomies, $post_id, $classes, $css_class );

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body_class

Filters the body CSS classes.

apply_filters( 'body_class', $classes, $css_class );

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Post Meta Hooks

added_post_meta

Fires after post meta is added.

do_action( 'added_post_meta', $meta_id, $post_id, $meta_key, $meta_value );

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updated_post_meta

Fires after post meta is updated.

do_action( 'updated_post_meta', $meta_id, $post_id, $meta_key, $meta_value );

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deleted_post_meta

Fires after post meta is deleted.

do_action( 'deleted_post_meta', $meta_ids, $post_id, $meta_key, $meta_value );

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add_post_meta

Fires before adding post meta.

do_action( 'add_post_meta', $post_id, $meta_key, $meta_value );

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update_post_meta

Fires before updating post meta.

do_action( 'update_post_meta', $meta_id, $post_id, $meta_key, $meta_value );

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delete_post_meta

Fires before deleting post meta.

do_action( 'delete_post_meta', $meta_ids, $post_id, $meta_key, $meta_value );

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Post Field Filters

edit_{$field}

Filters post field for editing.

apply_filters( "edit_{$field}", $value, $post_id );

Examples: edit_post_content, edit_post_title

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{$field}_edit_pre

Filters post field before editing (prefixed fields).

apply_filters( "{$field_no_prefix}_edit_pre", $value, $post_id );

Examples: content_edit_pre, title_edit_pre

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pre_{$field}

Filters post field before saving (prefixed fields).

apply_filters( "pre_{$field}", $value );

Examples: pre_post_content, pre_post_title

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{$field}_save_pre

Filters post field before saving (prefixed fields, alternate).

apply_filters( "{$field_no_prefix}_save_pre", $value );

Examples: content_save_pre, title_save_pre

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Featured Image Hooks

has_post_thumbnail

Filters whether post has a thumbnail.

apply_filters( 'has_post_thumbnail', $has_thumbnail, $post, $thumbnail_id );

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post_thumbnail_id

Filters the thumbnail attachment ID.

apply_filters( 'post_thumbnail_id', $thumbnail_id, $post );

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post_thumbnail_size

Filters the requested thumbnail size.

apply_filters( 'post_thumbnail_size', $size, $post_id );

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begin_fetch_post_thumbnail_html

Fires before fetching thumbnail HTML.

do_action( 'begin_fetch_post_thumbnail_html', $post_id, $post_thumbnail_id, $size );

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end_fetch_post_thumbnail_html

Fires after fetching thumbnail HTML.

do_action( 'end_fetch_post_thumbnail_html', $post_id, $post_thumbnail_id, $size );

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post_thumbnail_html

Filters the post thumbnail HTML.

apply_filters( 'post_thumbnail_html', $html, $post_id, $post_thumbnail_id, $size, $attr );

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post_thumbnail_url

Filters the post thumbnail URL.

apply_filters( 'post_thumbnail_url', $thumbnail_url, $post, $size );

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the_post_thumbnail_caption

Filters the displayed thumbnail caption.

apply_filters( 'the_post_thumbnail_caption', $caption );

---

Revision Hooks

wp_save_post_revision_check_for_changes

Filters whether to check for changes before saving revision.

apply_filters( 'wp_save_post_revision_check_for_changes', $check_for_changes, $latest_revision, $post );

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wp_save_post_revision_post_has_changed

Filters whether post has changed (for revision decision).

apply_filters( 'wp_save_post_revision_post_has_changed', $post_has_changed, $latest_revision, $post );

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_wp_post_revision_fields

Filters which fields are tracked in revisions.

apply_filters( '_wp_post_revision_fields', $fields, $post );

Default fields: post_title, post_content, post_excerpt

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wp_revisions_to_keep

Filters number of revisions to keep.

apply_filters( 'wp_revisions_to_keep', $num, $post );

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wp_{$post_type}_revisions_to_keep

Filters revisions per post type.

apply_filters( "wp_{$post->post_type}_revisions_to_keep", $num, $post );

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_wp_put_post_revision

Fires after a revision is saved.

do_action( '_wp_put_post_revision', $revision_id, $post_id );

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wp_restore_post_revision

Fires after a revision is restored.

do_action( 'wp_restore_post_revision', $post_id, $revision_id );

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wp_delete_post_revision

Fires after a revision is deleted.

do_action( 'wp_delete_post_revision', $revision_id, $revision );

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wp_post_revision_meta_keys

Filters meta keys to be revisioned.

apply_filters( 'wp_post_revision_meta_keys', $keys, $post_type );

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Sticky Post Hooks

post_stuck

Fires after a post is made sticky.

do_action( 'post_stuck', $post_id );

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post_unstuck

Fires after sticky is removed.

do_action( 'post_unstuck', $post_id );

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is_sticky

Filters whether a post is sticky.

apply_filters( 'is_sticky', $is_sticky, $post_id );

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Post Query Hooks

posts_where

Filters the WHERE clause of post queries.

apply_filters( 'posts_where', $where, $wp_query );

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posts_join

Filters the JOIN clause.

apply_filters( 'posts_join', $join, $wp_query );

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posts_orderby

Filters the ORDER BY clause.

apply_filters( 'posts_orderby', $orderby, $wp_query );

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posts_clauses

Filters all query clauses at once.

apply_filters( 'posts_clauses', $clauses, $wp_query );

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the_posts

Filters retrieved posts array.

apply_filters( 'the_posts', $posts, $wp_query );

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Slug/Permalink Hooks

wp_unique_post_slug

Filters the unique slug before generation.

apply_filters( 'pre_wp_unique_post_slug', $override_slug, $slug, $post_id, $post_status, $post_type, $post_parent );

Return non-null to short-circuit.

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wp_unique_post_slug

Filters the generated unique slug.

apply_filters( 'wp_unique_post_slug', $slug, $post_id, $post_status, $post_type, $post_parent, $original_slug );

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Attachment Hooks

add_attachment

Fires after an attachment is created.

do_action( 'add_attachment', $post_id );

---

edit_attachment

Fires after an attachment is updated.

do_action( 'edit_attachment', $post_id );

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attachment_updated

Fires after attachment update with before/after.

do_action( 'attachment_updated', $post_id, $post_after, $post_before );

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delete_attachment

Fires before an attachment is deleted.

do_action( 'delete_attachment', $post_id );

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deleted_attachment

Fires after an attachment is deleted.

do_action( 'deleted_attachment', $post_id );

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get_attached_file

Filters the attached file path.

apply_filters( 'get_attached_file', $file, $attachment_id );

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update_attached_file

Filters the file path before updating.

apply_filters( 'update_attached_file', $file, $attachment_id );

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Post Count Hooks

wp_count_posts

Filters post count results.

apply_filters( 'wp_count_posts', $counts, $type, $perm );

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wp_count_attachments

Filters attachment count results.

apply_filters( 'wp_count_attachments', $counts, $mime_type );

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Post Format Hooks

post_formats_rewrite_base

Filters the post format rewrite base.

apply_filters( 'post_formats_rewrite_base', 'type' );

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Page Hooks

wp_dropdown_pages

Filters the pages dropdown HTML.

apply_filters( 'wp_dropdown_pages', $output, $parsed_args, $pages );

---

wp_list_pages

Filters the pages list HTML.

apply_filters( 'wp_list_pages', $output, $parsed_args, $pages );

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wp_list_pages_excludes

Filters pages to exclude from list.

apply_filters( 'wp_list_pages_excludes', $exclude_array );

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Link/Pagination Hooks

wp_link_pages

Filters paginated post links HTML.

apply_filters( 'wp_link_pages', $output, $args );

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wp_link_pages_args

Filters pagination arguments.

apply_filters( 'wp_link_pages_args', $parsed_args );

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wp_link_pages_link

Filters individual page link.

apply_filters( 'wp_link_pages_link', $link, $i );

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Password Protection Hooks

post_password_required

Filters whether password is required.

apply_filters( 'post_password_required', $required, $post );

---

the_password_form

Filters the password form HTML.

apply_filters( 'the_password_form', $output, $post );

---

Common Usage Patterns

Modify Content Before Display

add_filter( 'the_content', function( $content ) {
    if ( is_single() ) {
        $content .= '<div class="author-bio">...</div>';
    }
    return $content;
} );

Track Post Changes

add_action( 'post_updated', function( $post_id, $post_after, $post_before ) {
    if ( $post_before->post_status !== $post_after->post_status ) {
        // Status changed
        log_status_change( $post_id, $post_before->post_status, $post_after->post_status );
    }
}, 10, 3 );

Custom Post Creation Logic

add_action( 'wp_after_insert_post', function( $post, $update, $post_before ) {
    if ( ! $update && $post->post_type === 'product' ) {
        // New product created
        setup_product_defaults( $post->ID );
    }
}, 10, 3 );

Filter Revision Fields

add_filter( '_wp_post_revision_fields', function( $fields, $post ) {
    if ( $post['post_type'] === 'book' ) {
        $fields['isbn'] = 'ISBN';  // Track custom field
    }
    return $fields;
}, 10, 2 );

Conditional Featured Images

add_filter( 'post_thumbnail_html', function( $html, $post_id, $thumb_id, $size, $attr ) {
    if ( empty( $html ) ) {
        // Return default image if no thumbnail
        return '<img src="' . get_template_directory_uri() . '/images/default.jpg" class="default-thumb" />';
    }
    return $html;
}, 10, 5 );

Prevent Certain Status Transitions

add_action( 'transition_post_status', function( $new, $old, $post ) {
    if ( $new === 'publish' && $post->post_type === 'article' ) {
        if ( ! has_post_thumbnail( $post->ID ) ) {
            // Revert to draft
            wp_update_post( array(
                'ID' => $post->ID,
                'post_status' => 'draft',
            ) );
            wp_die( 'Articles require a featured image before publishing.' );
        }
    }
}, 10, 3 );