Add Hook

Step 3 — Implementation pattern

Register in hooks()

public function hooks(): void {
    // ... existing hooks ...
    add_filter( 'the_content', [ $this, 'modify_content' ], 20 );
}

Priority guidelines:

• 10 — default, use when order doesn't matter.
• < 10 — must run before core/other plugins.
• > 10 — must run after core/other plugins.
• PHP_INT_MAX — must run absolutely last (e.g. final output sanitisation).

Implement the callback method

Filter example:

/**
 * Modifies the post content.
 *
 * @param string $content The original post content.
 * @return string The modified content.
 */
public function modify_content( string $content ): string {
    if ( ! is_singular( 'post' ) ) {
        return $content;
    }

    // ... apply transformation ...

    return $content;
}

Action example:

/**
 * Fires after a post is saved.
 *
 * @param int      $post_id Post ID.
 * @param \WP_Post $post    Post object.
 * @param bool     $update  Whether this is an update.
 */
public function after_post_save( int $post_id, \WP_Post $post, bool $update ): void {
    if ( wp_is_post_autosave( $post_id ) || wp_is_post_revision( $post_id ) ) {
        return;
    }

    // ... do the work ...
}

Step 4 — Custom hook best practices

When dispatching your own hook (so other code can extend it):

// Action
do_action( 'dekodeinteraktiv/plugin/after_item_created', $item_id, $item_data );

// Filter
$value = apply_filters( 'dekodeinteraktiv/plugin/item_title', $title, $item_id );

Rules:

• Prefix with <org>/<plugin-slug>/ to guarantee uniqueness.
• Document all custom hooks with a docblock above do_action / apply_filters.
• Filters must always return a value — even if they do nothing to it.

Step 5 — Verify

composer lint
composer lint-fix  # if needed
composer lint      # re-run to confirm clean