NiFi FlowFile v3 VS Code Extension

This extension adds a custom editor for FlowFile v3 documents and opens *.flowfile and *.flowfile-v3 files in a structured editor instead of plain text.

Project structure

• package.json: extension manifest, custom editor contribution, activation events, scripts
• src/extension.ts: activation logic, binary parser/serializer, and custom editor provider
• media/editor.js: webview UI logic for editing multiple FlowFile records
• media/editor.css: editor styling
• tsconfig.json: TypeScript build config
• .eslintrc.cjs: lint rules for TypeScript source

FlowFile v3 binary format support

The editor now uses a real FlowFile v3 binary stream model based on NiFiFF3 packaging:

• Each record starts with ASCII magic header: NiFiFF3
• Then attribute count (length encoded)
• Then repeated attribute key/value strings (each length encoded)
• Then 8-byte content length (big-endian)
• Then content bytes
• Multiple records can be concatenated in one file and are fully supported in the UI

Length encoding uses:

• 2-byte unsigned length when value is < 65535
• 0xFFFF marker followed by 4-byte unsigned length for larger values

UI behavior and assumptions

• The custom editor lets you add/remove/select multiple records in one file.
• Each record supports editing attributes and content.
• Content is presented and edited as UTF-8 text in the UI; saving writes UTF-8 bytes back into the FlowFile record.

Development

npm install
npm run compile
npm run lint
npm test