Metadata Presenter

The fb-metadata-presenter is a Rails engine, published as the metadata_presenter gem, that is responsible for rendering the MoJ Form Builder metadata into GOV.UK Design System components.

It is mounted into both fb-editor and fb-runner, so the same code renders a form whether it is previewed in the Editor or filled in by an end user in the Runner. Each host app supplies the surrounding behaviour: saving and loading data, whether pages are editable, and feature flags like reference numbers, payment links, save and return, and confirmation emails, so both apps share one consistent presentation layer.

Making changes to fb-metadata-presenter

1. Make your changes in fb-metadata-presenter then push to GitHub.
2. Specify the new branch in fb-editor and fb-runner. Run bundle to update Gemfile.lock (this is commented in the Gemfile).
3. Test locally with make setup. If the tests pass, push the changes to GitHub.
4. To test in staging, in the .circleci/config.yml file for both fb-runner and fb-editor, replace main with the new branch to be tested:
   • fb-runner: workflow.test_and_build.jobs.build_and_push_image_test
   • fb-editor: workflows.test_and_build.jobs.build_web_image
5. Bump metadata_presenter to a new minor version and update CHANGELOG.md.
6. Merge the fb-metadata-presenter branch.
7. Once all tests pass and regression looks ok, you can safely close these test PR’s.
8. Re-deploy fb-editor and fb-runner with the new metadata_presenter version which should now be available on RubyGems.

This page was last reviewed on 22 July 2026. It needs to be reviewed again on 22 October 2026 .