Class: Neo4j::Session

Inherits:

Object

• Object
• Neo4j::Session

show all

Defined in:

lib/neo4j/session.rb

Defined Under Namespace

Classes: CypherError

Constant Summary

@@current_session =

nil

@@all_sessions =

{}

@@factories =

{}

Class Method Summary (collapse)

• + (Neo4j::Session) current

  The current session.

• + (Object) current!

  Returns the current session or raise an exception if no session is available.

• + (Object) inspect
• + (Object) named(name)

  Returns a session with given name or else raise an exception.

• + (Object) on_session_available(&callback)

  Registers a callback which will be called immediately if session is already available, or called when it later becomes available.

• + (Object) open(db_type = :server_db, *params)

  Creates a new session to Neo4j.

• + (Object) open_named(db_type, name, default = nil, *params)
• + (Object) query(*args)
• + (Object) set_current(session)

  Sets the session to be used as default.

• + (Object) user_agent_string

Instance Method Summary (collapse)

• - (Object) _query(*params) abstract

  Same as #query but does not accept an DSL and returns the raw result from the database.

• - (Boolean) auto_commit?
• - (Object) begin_tx abstract
• - (Object) close abstract
• - (:embedded_db | :server_db) db_type
• - (Neo4j::Core::Query, Enumerable) query(options = {})

  Performs a cypher query.

• - (Object) running abstract

  Only for embedded database.

• - (Object) shutdown abstract

  Only for embedded database.

• - (Object) start abstract

  Only for embedded database.

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# File 'lib/neo4j/session.rb', line 115

def current
  @@current_session
end

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# File 'lib/neo4j/session.rb', line 120

def current!
  fail 'No session, please create a session first with Neo4j::Session.open(:server_db) or :embedded_db' unless current
  current
end

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# File 'lib/neo4j/session.rb', line 194

def inspect
  "Neo4j::Session available: #{@@factories && @@factories.keys}"
end

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# File 'lib/neo4j/session.rb', line 131

def named(name)
  @@all_sessions[name] || fail("No session named #{name}.")
end

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# File 'lib/neo4j/session.rb', line 143

def on_session_available(&callback)
  callback.call(Neo4j::Session.current) if Neo4j::Session.current

  add_listener do |event, data|
    callback.call(data) if event == :session_available
  end
end

Neo4j::Session.open(:server_db, 'http://localhost:7474', {basic_auth: {username: 'foo', password: 'bar'}})

connection = Faraday.new do |b|
  # faraday config
end
Neo4j::Session.open(:server_db, 'http://localhost:7474', connection: connection)

Neo4j::Session.open(:embedded_db, 'path/to/db')

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# File 'lib/neo4j/session.rb', line 97

def open(db_type = :server_db, *params)
  register(create_session(db_type, params))
end

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# File 'lib/neo4j/session.rb', line 101

def open_named(db_type, name, default = nil, *params)
  fail 'Multiple sessions is currently only supported for Neo4j Server connections.' unless db_type == :server_db
  register(create_session(db_type, params), name, default)
end

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# File 'lib/neo4j/session.rb', line 126

def query(*args)
  current!.query(*args)
end

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# File 'lib/neo4j/session.rb', line 137

def set_current(session)
  @@current_session = session
end

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# File 'lib/neo4j/session.rb', line 151

def user_agent_string
  gem, version = if defined?(::Neo4j::ActiveNode)
                   ['neo4j', ::Neo4j::VERSION]
                 else
                   ['neo4j-core', ::Neo4j::Core::VERSION]
                 end


  "#{gem} gem/#{version} (https://github.com/neo4jrb/#{gem})"
end

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# File 'lib/neo4j/session.rb', line 75

def _query(*params)
  fail 'not implemented'
end

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# File 'lib/neo4j/session.rb', line 35

def auto_commit?
  true # TODO
end

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# File 'lib/neo4j/session.rb', line 40

def begin_tx
  fail 'not impl.'
end

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# File 'lib/neo4j/session.rb', line 8

def close
  self.class.unregister(self)
end

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# File 'lib/neo4j/session.rb', line 31

def db_type
  fail 'not impl.'
end

Neo4j::Session.query.match("(c:person)-[:friends]->(p:person)").where(c: {name: 'andreas'}).pluck(:p).first[:name]

Neo4j::Session.query..match("(c:person)-[:friends]->(p:person)").where(c: {name: 'andreas'}).return(:p).to_cypher

Neo4j::Session.query("MATCH (c:person)-[:friends]->(p:person) WHERE c.name = \"andreas\" RETURN p").first[:p][:name]

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# File 'lib/neo4j/session.rb', line 68

def query(options = {})
  fail 'not implemented, abstract'
end

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# File 'lib/neo4j/session.rb', line 26

def running
  fail 'not impl.'
end

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# File 'lib/neo4j/session.rb', line 20

def shutdown
  fail 'not impl.'
end

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# File 'lib/neo4j/session.rb', line 14

def start
  fail 'not impl.'
end