Caylir

Cayley driver for Elixir

Warning

This module is experimental at the moment and may behave or change unexpectedly.

Tested cayley versions:

• 0.6.1
• 0.7.0
• 0.7.1
• 0.7.2
• 0.7.3
• 0.7.4

(see .travis.yml to be sure)

Package Setup

Add caylir as a dependency to your mix.exs file:

defp deps do
  [
    # ...
    {:caylir, "~> 0.8"},
    # ...
  ]
end

You should also update your applications to include all necessary projects:

def application do
  [
    applications: [
      # ...
      :caylir,
      # ...
    ]
  ]
end

Application Setup

Graph Definition

Defining a graph connection requires defining a module:

defmodule MyApp.MyGraph do
  use Caylir.Graph, otp_app: :my_app
end

The :otp_app name and the name of the module can be freely chosen but have to be linked to a corresponding configuration entry. This defined graph module needs to be hooked up into your supervision tree:

children = [
  # ...

  # elixir < 1.5.0
  MyApp.MyGraph.child_spec(),
  # elixir >= 1.5.0
  MyApp.MyGraph,

  # ...
]

Configuration (static)

The most simple way is to use a completely static configuration:

config :my_app, MyApp.MyGraph,
  host: "localhost",
  pool: [max_overflow: 10, size: 50],
  port: 64210

Configuration (dynamic)

If you cannot, for whatever reason, use a static application config you can configure an initializer module that will be called every time your graph is started (or restarted) in your supervision tree:

config :my_app, MyApp.MyGraph,
  init: {MyInitModule, :my_init_fun}

defmodule MyInitModule do
  @spec my_init_fun(module) :: :ok
  def my_init_fun(graph) do
    config =
      Keyword.merge(
        graph.config(),
        host: "localhost",
        port: 64210
      )

    Application.put_env(:my_app, graph, config)
  end
end

When the graph is started the function will be called with the graph module as the first (and only) parameter. This will be done before the graph is available for use.

The function is expected to always return :ok.

Usage

Writing Data:

# single quad
MyApp.MyGraph.write(%{
  subject: "graph",
  predicate: "connection",
  object: "target"
})

# multiple quads (bulk write)
MyApp.MyGraph.write([quad_1, quad_2])

Querying data:

# Gizmo syntax!
query = "graph.Vertex('graph').Out('connection').All()"

# Default result limit
MyApp.MyGraph.query(query)

# Custom result limit (limited + unlimited)
MyApp.MyGraph.query(query, limit: 3)
MyApp.MyGraph.query(query, limit: -1)

Deleting Data:

# single quad
MyApp.MyGraph.delete(%{
  subject: "graph",
  predicate: "connection",
  object: "target"
})

# multiple quads (bulk delete)
MyApp.MyGraph.delete([quad_1, quad_2])

Query Language Configuration

If you are using a cayley version prior to 0.7.0 (e.g. 0.6.1) you may need to change the default query language used:

# default (suitable for cayley >= 0.7.0)
config :my_app, MyApp.MyGraph,
  language: :gizmo

# old query language used in 0.6.1
config :my_app, MyApp.MyGraph,
  language: :gremlin

Query Limit Configuration

You can define a default query limit by adding it to your graph config:

config :my_app, MyApp.MyGraph,
  limit: -1

License

Apache License, Version 2.0