Session

Database Session

API

• Neo4j::Session

Embedded or Server sessions

There are currently two available types of session, one for connecting to a neo4j server and one for connecting to the embedded Neo4j database (which requires JRuby).

Using the Neo4j Server: :server_db Open a IRB/Pry session:

  require 'neo4j-core'
  # Using Neo4j Server Cypher Database
  session = Neo4j::Session.open(:server_db)

Session Configuration

Example, Basic Authentication:

  Neo4j::Session.open(:server_db, 'http://my.server', basic_auth: { username: 'username', password: 'password'})

HTTP(S) connections are handled using the Faraday gem. You can send options to its initialization method with an initialize key.

Neo4j::Session.open(:server_db, 'http://my.server', basic_auth: { username: 'username', password: 'password'}, initialize: { ssl: { verify: true }})

See Faraday's documentation for more info about this.

Embedded Session

Using the Neo4j Embedded Database, :embedded_db

  # Using Neo4j Embedded Database
  session = Neo4j::Session.open(:embedded_db, '/folder/db', auto_commit: true)
  session.start

To stop the database (only supported via the embedded database) use

session.shutdown
session.running? #=> false
session.close # make the session not current/default

Session.current

When a session has been created it will be stored in the Neo4j::Session object. Example, get the default session

session = Neo4j::Session.current

Multiple Sessions

The default session is used by all operation unless specified as the last argument. For example create a node with a different session:

my_session = Neo4j::Session.create_session(:server_db, "http://localhost:7474")
Neo4j::Node.create(name: 'kalle', my_session)

When using the Neo4j Server: :server_db, multiple sessions are supported.

Neo4j-core v3 and v4

The open_named method controls named sessions. This method takes two extra parameters, the second parameter is the session name, and the third parameter is whether the new session should over-ride the default session (becoming the session returned by calling Neo4j::Session.current). Valid options are true (always become current), false (never become current) and nil (become current if no existing current session).

Neo4j::Session.open_named(:server_db, :test, true, "https://localhost:7474")
session = Neo4j::Session.named :test # Returns the session named :test.
session = Neo4j::Session.current # Returns the session named :test, because the 'default' flag was set to true.

Neo4j-core v5 (as of 3/16/2015)

The open_named method has been removed, you can now create named sessions using Neo4j::Session.open. Use the name and default keys to control this behavior.

Neo4j::Session.open(:server_db, 'http://localhost:7474', name: :test, default: true)

Neo4j 2.2 Authentication

Starting with Neo4j 2.2, the database provides basic authentication using tokens. The gem supports it starting with v3.1.0. Create a new session as you would otherwise and use the database username and password as basic authentication parameters. The gem will detect that the server expects credentials and a token, will see your username/password, and configure the session.

The fundamentals of the Authentication API Endpoint are accessible from the Neo4j::Server::CypherAuthentication class. See specs at https://github.com/neo4jrb/neo4j-core/blob/master/spec/neo4j-server/e2e/cypher_authentication_spec.rb for a demonstration or YARD.