• Support block children in editor elements alongside value.

  Blocks were introduced in #55827, but only as an alternative to the value argument: the block was captured and used as the initial editor content, making it either value OR block — not both.

  The block semantics are now changed so that blocks render as DOM children of the editor element instead. Value and block are now independent: value flows into the editor's content binding (the hidden input for Trix, the value attribute for custom editors), while the block renders as inner DOM children — useful for embedding custom elements such as prompt menus or toolbar extensions.

  This enables other editors like Lexxy to use the block form for configuration — injecting child elements into the editor tag — while the rich text value is preserved separately.

  Trix preserves the original block-as-initial-value contract by capturing the block in TrixEditor::Tag#render_in when no value is present, keeping its hidden input populated as before.

  Jorge Manrubia

• Render MissingAttachable as "☒" in plain text.

  Previously, Content#to_plain_text would replace a MissingAttachable with a blank string. Now it renders the same "☒" character used in the HTML representation.

  Mike Dalessio

• Add to_markdown to Action Text, mirroring to_plain_text.

  Converts rich text content to Markdown, supporting headings, bold, italic, strikethrough, inline code, code blocks, blockquotes, ordered and unordered lists, links, tables, and attachments. Custom attachment representations can be provided by implementing attachable_markdown_representation on the attachable model.

  message = Message.create!(content: "<h1>Hello</h1><p>This is <strong>bold</strong></p>")
  message.content.to_markdown # => "# Hello\n\nThis is **bold**"

  Mike Dalessio

• Make ActionText::Attachable#read_attribute_for_serialization public.

  Sally Hall

• Install generator now detects which JS package manager to use when installing javascript dependencies for the editor.

  David Lowenfels

• Deprecate Trix-specific classes, modules, and methods

  • ActionText::Attachable#to_trix_content_attachment_partial_path. Override #to_editor_content_attachment_partial_path instead.
  • ::ActionText::Attachments::TrixConversion
  • ActionText::Content#to_trix_html.
  • ActionText::RichText#to_trix_html.
  • ::ActionText::TrixAttachment

  Sean Doyle

• Validate RemoteImage URLs at creation time.

  RemoteImage.from_node now validates the URL before creating a RemoteImage object, using the same regex that AssetUrlHelper uses during rendering. URLs like "image.png" that would previously have been passed to the asset pipeline and raised a ::ActionView::Template::Error are rejected early, and gracefully fail by resulting in a MissingAttachable.

  Mike Dalessio

Please check [8-1-stable]) for previous changes.