Node-Neo4j

⚠️ NOTE: This library is no longer under development. Neo4j 3.0 comes with a first-party JavaScript driver which obviates the need for this library. ⚠️

This is a client library for accessing Neo4j, a graph database, from Node.js. It uses Neo4j's REST API, and supports Neo4j 1.5 through Neo4j 2.1.

(Note that new 2.0 features like labels and constraints are only accessible through Cypher for now -- but Cypher is the recommended interface for Neo4j anyway. This driver might change to wrap Cypher entirely.)

Update: node-neo4j v2 is under development and almost finished! Read the full spec here, and follow the progress in pull #145. If you're comfortable using pre-release code, alpha versions are available on npm; we at FiftyThree are running them in production. =)

Installation

npm install [email protected] --save

Usage

To start, create a new instance of the GraphDatabase class pointing to your Neo4j instance:

var neo4j = require('neo4j');
var db = new neo4j.GraphDatabase('http://localhost:7474');

Node.js is asynchronous, which means this library is too: most functions take callbacks and return immediately, with the callbacks being invoked when the corresponding HTTP requests and responses finish.

Here's a simple example:

var node = db.createNode({hello: 'world'});     // instantaneous, but...
node.save(function (err, node) {    // ...this is what actually persists.
    if (err) {
        console.error('Error saving new node to database:', err);
    } else {
        console.log('Node saved to database with id:', node.id);
    }
});

Because async flow in Node.js can be quite tricky to handle, we strongly recommend using a flow control tool or library to help. Our personal favorite is Streamline.js, but other popular choices are async, Step, Seq, TameJS and IcedCoffeeScript.

Once you've gotten the basics down, skim through the full API documentation to see what this library can do, and take a look at @aseemk's node-neo4j-template app for a complete usage example. (The models/User.js file in particular is the one that interacts with this library.)

This library is officially stable at "v1", but "v2" will almost certainly have breaking changes to support only Neo4j 2.0 and generally improve the API (roadmap). You can be sheltered from these changes if you simply specify your package.json dependency as e.g. 1.x or ^1.0 instead of *.

Development

git clone [email protected]:thingdom/node-neo4j.git
cd node-neo4j
npm install && npm run clean

You'll need a local installation of Neo4j (links), and it should be running on the default port of 7474 (neo4j start).

To run the tests:

npm test

This library is written in CoffeeScript, using Streamline.js syntax. The tests automatically compile the code on-the-fly, but you can also generate compiled .js files from the source ._coffee files manually:

npm run build

This is in fact what's run each time this library is published to npm. But please don't check the generated .js files in; to remove:

npm run clean

When compiled .js files exist, changes to the source ._coffee files will not be picked up automatically; you'll need to rebuild.

If you npm link this module into another app (like node-neo4j-template) and you want the code compiled on-the-fly during development, you can create an index.js file under lib/ with the following:

require('coffee-script/register');
require('streamline/register');
module.exports = require('./index._coffee');

But don't check this in! That would cause all clients to compile the code on-the-fly every time, which isn't desirable in production.

Changes

See the Changelog for the full history of changes and releases.

License

This library is licensed under the Apache License, Version 2.0.

Feedback

If you encounter any bugs or other issues, please file them in the issue tracker.

We also now have a Google Group! Post questions and participate in general discussions there.