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Web UI

Usage​

The Web UI is a Scala.js single‑page application (SPA) that can be used in a few ways. Pick the option that matches how you run your backend:

The simplest way is to use the workflows4s-web-ui-bundle, which contains the prebuilt web assets packaged as JAR resources. It also defines Tapir endpoints that serve those assets.

Dependency:

"org.business4s" %% "workflows4s-web-ui-bundle" % "0.4.0"

See Getting Started for an example usage.

2) Host the bundle with a separate web server​

If you don't want to serve the assets from your Scala application, you can host the same static bundle on any web server (NGINX, CDN, etc.).

To do so, unpack the assets from the JAR file and expose to the web server.

Dependency:

"org.business4s" %% "workflows4s-web-ui-bundle" % "0.4.0"

3) Direct Scala.js usage (advanced)​

If you need more customization, you can use the raw Scala code for the UI and incorporate it (fully or partially) into a separate Scala.js project.

"org.business4s" %% "workflows4s-web-ui" % "0.4.0"

UI configuration​

The Web UI can be configured with the API URL. On page load, it fetches a config.json file and reads the apiUrl value from it.

This file is exposed automatically when serving the bundle via Tapir; in other setups, you must provide it yourself.

Important:

  • The UI can be served under any base path, but config.json is requested via a relative path. Therefore, the public URL used to access the UI must end with a trailing slash (/); otherwise, the config will not load correctly.
  • For this reason, configure your HTTP server to redirect {basePath} to {basePath}/. Unfortunately, this is not possible with plain Tapir alone.