README.md

QLever UI2 Backend

This is the backend service for QLever-UI2. It provides a set of REST APIs that are consumed by the frontend. These include:

• wikidata identifier resolving and search
• Wikidata query extension suggestion
• sparql query execution.

Architecture / Stack

• The backend is written in node.js, with
  • flow for type annotation
  • babel for transpiling the source for older node versions
• We use koajs as web server.
• sparql queries are parsed using SPARQL.JS
• The backend consumes two external services:
  • Wikidata Frontend
  • QLever API

REST APIs

The rest APIs are documented in qlever-ui2-documentation/_pages/backend/

Usage

• yarn dev - start in development mode
• yarn build - transpile the code for your current node version. keep in mind, in order to run it for production qlever-ui2-shared needs to be build too.
• yarn production - starts the backend in production mode.
• yarn test - runs the tests
• yarn lint - lint source code
• yarn lint:fix - lint source code and fix all fixable errors

Configuration

Configuration is done using environment variables

environment variable	default value
WIKIDATA_FRONTEND_API	http://alicudi.informatik.privat:7001
QLEVER_API	http://qlever.informatik.uni-freiburg.de/api/wikidata-full

There is also the .babelrc.js, where one can configure the target node version (default: the one running the build)