[miinhho]

What is this PR for?

The Angular notebook UI only supports exporting notes as .zpln, while the classic UI also supports Jupyter notebook (.ipynb) export.

This PR adds an .ipynb export button to the Angular notebook toolbar. It uses the existing server-side conversion protocol and adds the corresponding SDK message types. The two export buttons have distinct tooltips and accessible names.

Existing .zpln export behavior is unchanged. Both buttons are hidden in report mode and disabled when viewing a revision.

What type of PR is it?

Improvement

Todos

• - Add SDK message types and a request method for notebook conversion.
• - Add the ipynb export button and download handling.
• - Add type-contract and E2E regression coverage.

What is the Jira issue?

• https://issues.apache.org/jira/browse/ZEPPELIN-6633

How should this be tested?

Run the following commands from zeppelin-web-angular:

npm run typecheck:sdk-contracts
npm run check:websocket-contract
npm run test:shell

With Zeppelin running at http://localhost:8080, run:

npm run e2e:fast -- tests/notebook/action-bar/action-bar-functionality.spec.ts

The export regression test verifies the downloaded notebook’s cells, Unicode content and filename, and absence of a UTF-8 BOM. It also checks that export still works without duplicate downloads after navigating away and reopening the note, and that .zpln export preserves the original note.

For manual verification:

1. Open a note containing markdown and code paragraphs in the Angular UI.
2. Click Export this note (ipynb). Open the downloaded file in Jupyter and check the cells and content.
3. Navigate away and reopen the note without refreshing the browser. Export again and check that only one file is downloaded.
4. Use Export this note (zpln) to check that Zeppelin-format export still works.
5. Switch to report mode and check that both export buttons are hidden. With revision-capable storage, open a historical revision and check that both buttons are disabled.

Screenshots (if appropriate)

Questions:

• Does the license files need to update? No.
• Is there breaking changes for older versions? No.
• Does this needs documentation? No.

[voidmatcha]

LGTM 👍