AshNeo4j
View SourceAsh DataLayer for Neo4j, configurable using a simple DSL
Installation
Add to the deps:
def deps do
[
{:ash_neo4j, "~> 0.1.1"},
]
end
Usage
Configure AshNeo4j.DataLayer
as data_layer:
within use Ash.Resource
options:
use Ash.Resource,
data_layer: AshNeo4j.DataLayer
Configuration
Each Ash.Resource requires configuration of its AshNeo4j.DataLayer. An example Comment resource is given below, it can belong to a Post resource.
defmodule Comment.Resource do
use Ash.Resource,
data_layer: AshNeo4j.DataLayer
neo4j do
label :Comment
store [:id, :title]
translate id: :uuid
relate [{:post, :BELONGS_TO, :outgoing}]
end
actions do
default_accept(:*)
defaults([:create, :read, :update, :destroy])
end
attributes do
uuid_primary_key(:id)
attribute(:title, :string, public?: true)
end
relationships do
belongs_to(:post, Post, public?: true)
end
end
Label
The DSL is used to label the Ash Resource's underlying graph node.
neo4j do
label :Comment
end
Store
The DSL is used to store the Ash Resource's attributes as node properties, without translation.
neo4j do
store [:id, :title, :score, :public, :unique]
end
Translate
The DSL may be used to translate the Ash Resource's attributes to node properties.
neo4j do
translate id: :uuid
end
Relate
The DSL is used to direct any node relationships.
neo4j do
relate [{:post, :BELONGS_TO, :outgoing}]
end
Installing Neo4j and Configuring Boltx
ash_neo4j uses neo4j which must be installed and running.
Your Ash application needs to configure, start and supervise boltx, see boltx documentation. Make sure to configure any required authorisation.
I've used Neo4j community edition 4.4 (bolt 4.4) and to connect using boltx I needed to also set the environment variable BOLT_VERSIONS=4.4
to steer [bolt protocol handshake] (https://neo4j.com/docs/bolt/current/bolt/handshake).
Limitations and Future Work
Currently ash_neo4j only supports Ash read actions, with some limited support for relationships. Support for create, update and destroy actions is next.
Collaboration on ash_neo4j welcome via github, please use discussions and/or issues as appropriate.
Acknowledgements
Thanks to the Ash Core for ash 🚀, including ash_csv which was an exemplar.
Thanks to Sagastume for boltx which AFAIK was based on bolt_sips by Florin Patrascu.
Thanks to the Neo4j Core for neo4j which pioneered graph databases.