daml/navigator/README.md
Andreas Herrmann ee0fa3643f Remove git-revision from dependency graph (#3365)
* Remove git-revision from dependency graph

The navigator binary depended on the current git-revision. The issue is
that any target/test depending on the git-revision will have to be
rebuilt/rerun on every commit.

The navigator package itself was careful to avoid unnecessary
rebuilds/reruns. However, the SDK release tarball depends on the
navigator binary and thereby on the git-revision. The daml-assistant
integration tests, which depend on the SDK release tarball, therefore
had to be rerun on every commit.

This change removes the git-revision from the navigator alltogether. For
issue reporting the SDK version is still available.

* Remove unused git-revision and workspace_status
2019-11-07 13:29:31 +00:00

3.0 KiB

Navigator

The Navigator is a web-app that connects to any Digital Asset ledger and allows the user to inspect contracts, create contracts, and exercise choices.

The Navigator can be used in development mode (see below) or packaged into a "fat" JAR that includes the compiled frontend assets for distribution.

Navigator architecture

To learn more about developing the different parts of the Navigator see:

Building Navigator

To build a "fat" JAR of the Navigator that includes the pre-compiled front-end assets, run:

bazel build //navigator/backend:navigator-binary_deploy.jar

This produces a "fat" JAR bazel-bin/navigator/backend/navigator-binary_deploy.jar which can be run with:

java -jar bazel-bin/navigator/backend/navigator-binary_deploy.jar

Notable things in the Navigator build:

backend/src/test/resources/schema.graphql

Manually written, must be consistent with backend/src/main/scala/com/digitalasset/navigator/graphql/GraphQLSchema.scala. Consistency is checked in a test.

frontend/src/**/api/Queries.ts

Generated from backend/src/test/resources/schema.graphql with an external codegen tool. Currently, these files are checked in and updated with make update-graphql-types.

frontend bundled code

Code from frontend/src/**/*.ts*, compiled using TypeScript, and bundled with Webpack. Output includes:

  • bundle-[hash].js: bundled frontend code, name uses content hasing.
  • browsercheck-[hash].js: tiny module for checking browser compatibility, name uses content hasing.
  • Several image and font files, referenced by the above modules. File names use content hashing.
  • index.html: Single page application main entry, references the above modules.

Note: Browsers are instructed never to cache index.html, and indefinitely cache all other files. This is why content hashing is used.

backend binary

Scala binary, compiled as a fat JAR. Code from backend/src/**/*.scala, bundled frontend code is copied to backend/src/main/resources/frontend.

backend version

The version is included as resource files in the Navigator fat jar. This is to reduce rebuild times when the version changes.

frontend development build

For developing frontend code, webpack-dev-server is used. This serves the current frontend code on a separate port, and does:

  • Watch *.ts files for changes
  • Perform incremental builds
  • Send a push notification to the browser, automatically reloading the page when the build is finished.
  • Forward network requests to a different port, where a Navigator backend is expected to run.

This is orders of magnitude faster than what the current Bazel build offers, so it is desirable to keep the webpack-dev-server setup working.

Note, the browser is instructed to cache assets based on the SDK version. During development this is too aggressive and you will need to manually refresh to see updates to the front-end.