This post talks about InterMine-Neo4j API and its Swagger integration.

Background

In the past blog posts I described that we have decided to query InterMine Neo4j Graph using Cypher and how I am going to convert PathQuery to Cypher. To expose the Neo4j Query Service, it was decided to keep the API endpoints and response same as the InterMine API service so that BlueGenes can be configured to work with it easily at later stages.

Swagger UI

Swagger UI is a popular API documenting tool using which anyone can visualize and interact with your API’s resources without having any of the implementation logic in place. It’s automatically generated from your Swagger specification, with the visual documentation making it easy for back end implementation and client side consumption.

InterMine-Neo4j API

The API is developed using Jersey framework which provides support for JAX-RS APIs in Java. The code can be found is intermine-neo4jwebapp sub-project in the intermine/neo4j repository.

You can play with the InterMine-Neo4j API via Swagger UI at intermine-neo4jwebapp.herokuapp.com. There are two endpoints in the API so far,

  • query/cypher - This returns the Cypher equivalent of any Path Query.

  • query/results - This endpoint returns the results of a Path Query by converting it into Cypher and running that Cypher against InterMine-Neo4j Graph.

Integrating API with Swagger

Documenting InterMine-Neo4j API with Swagger involves the following steps.

Set up swagger-core in the project.

I used Swagger Core Jersey 2.X Project Setup 1.5 guide to add swagger-core to the projects. The information given in this guide is as per Maven projects. As we use Gradle as the build tool at InterMine, I had to do add dependencies differently. The other steps remain more or less the same.

Add Annotations to the Code

The next step is to add annotations to the API code. At Swagger-Core Annotations page you can find the documentation of all the annotations available with swagger-core.

Preview swagger.json

If the above two steps are executed properly, you should be able to see swagger.json generated for your code at {swagger.api.basepath}/swagger.json. For example, in our case, the swagger.json is generated at http://intermine-neo4jwebapp.herokuapp.com/service/swagger.json.

Add Swagger UI code to your project

The next step is to download the Swagger UI code from the dist folder in the swagger/swagger-ui repository and place it in the webapp folder of the project.

Configuring Swagger UI

Among all the files that are downloaded in the previous step, we need to configure index.html. We need to update the url property in the <script> tag at the end of this file by pasting the link to our generated swagger.json file.

After following all the steps properly, you should be able to see the generated Swagger Documentation of the API. :)

Feel free to checkout Swagger UI of InterMine Neo4j API at http://intermine-neo4jwebapp.herokuapp.com/ and stay tuned for more updates.