Gremlin for graph databases which implement the TinkerPop3 property graph data model.
npm install gremlin-v3gremlin-v3
============
**NOTE: This project is no longer being maintained. The project owners instead now use ts-tinkerpop,
which takes advantage of ts-java. We suggest you take a look at those two
projects.**
Implementation of Gremlin/TinkerPop3 for node.js. Gremlin-v3 is a javascript wrapper around the TinkerPop3 API. The node-java module provides the bridge between node and Java.
NOTE: This package is compatible with TinkerPop3. For TinkerPop2 compatibility, see the upstream repository gremlin-node.
``javascript
var Gremlin = require('gremlin');
var gremlin = new Gremlin({
classpath: [ ... ],
options: [ ... ]
});
var TinkerGraphFactory = gremlin.java.import('com.tinkerpop.gremlin.tinkergraph.structure.TinkerFactory');
var graph = TinkerGraphFactory.createClassicSync();
var g = gremlin.wrap(graph);
g.V('name', 'marko').next(function (err, v) {
v.value('name', function (err, value) {
console.log(value);
});
});
`
Gremlin-v3 supports the use of Promises/A+ for most functions taking a callback. For example, a portion of the above code could be written as:
`javascript`
g.V('name', 'marko').next().then(
function (v) {
v.value('name').then(console.log);
});
This snippet by itself may seem underwhelming, but consider that with some enhanecments to the gremlin-console application, promises make it possible to interact with gremlin in the console as if the promise-returning functions returned values:
`
node > var pipe = g.V('name', 'marko')
node > var v = pipe.next()
node > v.value('name')
'marko'
The gremlin-console application contained in this package does not yet have these enhancements. For early access to a console with these enhancements, use the repository gremlin-repl.
Bridge API to connect with existing Java APIs. Please read the __node-java__ installation notes, as it outlines how to install the node-java module on specific platforms and its dependencies.
NOTE: TinkerPop3 requires Java 1.8.
Maven enables the installation of the base jar files.
`bash`
$ npm install gremlin-v3
gremlin-v3 includes the required .jar files for Gremlin and the TinkerPop stack. It doesn't include any backend specific jars for databases such as Titan or OrientDB.
The Gremlin constructor takes in an object with two properties; classpath which allows you to load in jar files from your own project and options which allows you to supply parameters to the Java runtime.
`javascript`
var Gremlin = require('gremlin');
var gremlin = new Gremlin({
classpath: [
path.join(__dirname, '..', 'target', '*', '.jar')
],
options: [
'-XX:+UseThreadPriorities',
'-XX:ThreadPriorityPolicy=42',
'-XX:+UseParNewGC',
'-XX:+UseConcMarkSweepGC',
'-XX:+CMSParallelRemarkEnabled',
'-XX:SurvivorRatio=8',
'-XX:MaxTenuringThreshold=1',
'-XX:CMSInitiatingOccupancyFraction=75',
'-XX:+UseCMSInitiatingOccupancyOnly',
'-XX:+UseTLAB',
'-XX:+UseCondCardMark'
]
});
As mentioned above, gremlin-v3 only includes jars for the reference TinkerPop3 implementation, TinkerGraph.
To use another database implementing the TinkerPop3 property graph interfaces, the Gremlin constructor must point to a location with the databases compiled jars.
Once the dependent jars are properly loaded into the Java runtime, a graph instance must be created and passed to gremlin.wrap.
Note: Titan 0.4/0.5 is not compatible with TinkerPop3. Titan 0.9 is under development, and has not yet beeen tested with this package.
`javascript`
var TinkerGraphFactory = gremlin.java.import('com.tinkerpop.gremlin.tinkergraph.structure.TinkerFactory');
var graph = TinkerGraphFactory.openSync();
var g = gremlin.wrap(graph);
Once you have connected to the database, you are able to call all implementation specific database methods. For example here's how you would add two Vertices and an Edge and associate them in an OrientDB graph.
`javascript
var luca = graph.addVertexSync(null);
luca.setPropertySync( 'name', 'Luca' );
var marko = graph.addVertexSync(null);
marko.setPropertySync( 'name', 'Marko' );
var lucaKnowsMarko = graph.addEdgeSync(null, luca, marko, 'knows');
graph.commitSync();
``
A good resource to understand the Gremlin API (for TinkerPop2) is GremlinDocs. Most of the examples given at GremlinDocs have been translated to work in a node REPL, and encoded to run as unit tests, but in a separate repository. See gremlin-repl, and in particular these expected output files:
1. gremlindocs-transform
2. gremlindocs-filter
3. gremlindocs-sideeffects
4. gremlindocs-branch
5. gremlindocs-methods
TinkerPop3:
* Jim Lloyd - jimlloyd
TinkerPop2:
* Frank Panetta - Follow @entrendipity
* Anthony Pesch - inolen
Jared Camins-Esakov
Copyright (c) 2013 entrendipity pty ltd
Parts copyright (c) 2013 C & P Bibliography Services, LLC
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The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
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