Update and test Neo4j plugin

[mbastian]

We used to have a Neo4j plugin but it's out-dated and no longer works with recent versions of Neo4j.

The old plugin had fairly advanced features like lazy loading and export back to Neo4j. I would recommend to rather start simple and limit the scope to import only, based on Cypher query.

Definition of done

• Supports Bolt and Http protocols
• Can detect the DB version and use the appropriate driver (3 and 4?)
• Graph is imported using the ImportAPI (so that one gets validation etc.)
• Unit tests to avoid regressions in the future
• Plugin is released with documentation

Resources

• https://neo4j.com/docs/http-api/current/actions/begin-a-transaction/
• https://neo4j.com/docs/bolt/current/bolt/
• https://github.com/gephi/gephi/wiki/Spigot-importer-with-Wizard

[sim51]

See branch neo4j-bolt-plugin. It works for Neo4j 4.X (& Java 11 but it's the standard with Gephi).

Remaining tasks :

• [x] Test on big dataset (> 10000 nodes to check the fetchSize) and see the progress ticket (perhaps add each parsed node on the progress ticket ?, Is it cheap ?)
• [ ] Cancel an import
• [ ] Write better readme with specs of the imports (ie. user manual ?)
• [ ] Better UI layout ? (optional) (need help on this, I'm a newbie, and I would like to do some flexible layout, based on the with/height of the Panel)

[mbastian]

@sim51 Not sure if adding progress for each node is a good idea. It would add some overhead I think.

[sim51]

yeah, and it's fast enough to not be facing to the issue "Is my import frozen ?"

[mbastian]

Congrats, the plugin is published: https://gephi.org/plugins/#/plugin/neo4j-plugin

Fantastic work, thank you @sim51!