WeWoo

Wewoo is a small wrapper library that provides for graph database management using Ruby. Any graph databases that supports the Rexster graph server REST API can be integrated with Wewoo.

Add this line to your application's Gemfile:

gem 'wewoo'

And then execute:

$ bundle

Or install it yourself as:

$ gem install wewoo

Wewoo comes bundled with a REPL console to make for experimentation with the graph database using Ruby a joy.

$ wewoo

Dependending on your Rexster configuration, you will need to specify the host and port to tell Wewoo how to connect. The default url is localhost:8182. You may optionaly choose to set the configuration in a shell environment variable WEWOO_URL ie WEWOO_URL='http://localhost:8185'

# List out all available graphs
Wewoo::Graph.available_graphs #=> ["test_graph", "my_awesome_graph"]

# Connect to an existing graph on localhost:8182
g = Wewoo::Graph.new( :my_awesome_graph )
# or...
g = Wewoo::Graph.new( :my_awesome_graph, 'localhost', 9000 )

# List out all vertices
g.V # => [v(95084), v(95072), v(95076), v(95088), v(95080)]

# List out all edges
g.E # => [e(1lIN-oJG-4K) [95088-created-95076], e(1lIJ-oJy-4K) [95080-created-95084]]

Most graph database don't allow setting an id on a graph element. Wewoo errs on letting the graph implementation assign an internal id. It is usually considered good practice to keep vertex properties to a minimum. Wewoo provides a special property :gid to integrate the graph element with another data source. You can leverage :gid to represent a foreign key to another store. Hence :gid must be unique. If not set the gid will refer to the underlying graph implementation id.

v = g.add_vertex( name: 'Fred', age: 20, active: true, gid: 'user_900' )
v.id        #=> 1234
v.gid       #=> 'user_900'
v.props     #=> {name: 'Fred', age: 20, active: true}
v.props.age #=> 20

v1 = g.add_vertex( name: 'Fred' )
v2 = g.add_vertex( name: 'Blee' )
e  = g.add_edge( v1, v2, :friend, timestamp: Time.now )
e.id    #=> 1234
e.gid   #=> 1234
e.props #=> {"timestamp"=>"2014-03-01 13:55:26 -0700"}

Wewoo provides two way to delete a graph element. If you have a handle on the instance, you can call destroy on it directly. If not you can remove an element by calling the associated remove method on a graph instance using the graph element id. NOTE: By virtue of a graph database, when deleting a vertex, all associated edges will be deleted.

# Delete edge with id 1234
g.e( 1234 ).destroy
# or ...
g.remove_edge( 1234 )

# Delete a vertex with id 5678
g.v( 5678 ).destroy
# or...
g.remove_vertex( 5678 )

# Clear out the graph
g.clear

The power of graph database is in traversal. Traversal in Wewoo is made available using the Gremlin graph api.

# Find all vertices outbound from vertex 1234
g.v( 1234 ).out #=> [v(4567)]

# Find all vertices inbound to vertex 1234
g.v( 1234 ).in  #=> [v(7890), v(7891)]

# Find all vertices directly connected to vertex 1234
g.v( 1234 ).both #=> [v(7890), v(7891), v(4567)]

# Find all edges connected to vertex 1234 with labels fred or created
g.v(1234).bothE( :fred, :created) #=> [e(1lIJ-oJy-4K) [95080-created-95084]]

# Find all vertices with name property blee
g.find_vertices( :name, 'blee' ) #=> [v(1234)]

# Find vertex with gid 1234
g.find_first_vertex( :gid, 1234 ) #=> [v(567)]

# Find vertex with id 456
g.find_vertex( 456 ) #=> [v(456)]
# or...
g.v( 456 )           #=> [v(456)]

# Paging support...
g.find_vertices( 'enabled', true, 1, 2 ) #=> [v(7890), v(7891)]

You can access the full gremlin query api using the Wewoo::Graph#query method. Wewoo does its best to construct graph elements objects with the returning results.

# Find all vertices who's name is fred
g.query( "g.V.out.groupCount.cap") #=> {v(113420)=>2, v(113416)=>2, v(113412)=>1}

# Find all edge with weight < 0.5
g.q( "g.E.has( 'weight', T.lt, 0.5f)" ) #=> [e(1xSj-tve-2W) [113412-friend-113416]]

• 0.1.0 Initial drop
• 0.1.1 Disable user defined IDs as most graphs disallow
• 0.1.2 Bug fixes and spec updates
• 0.1.3 Spec'ed out Gremlin API
• 0.1.4 Refactor graph elements
• 0.1.5 Beef up specs + README
• 0.1.6 Clean up
• 0.1.7 Added logger

1. Fork it
2. Create your feature branch (git checkout -b my-new-feature)
3. Commit your changes (git commit -am 'Add some feature')
4. Push to the branch (git push origin my-new-feature)
5. Create new Pull Request

Wewoo is released under the MIT license.