Building nested JSON from graph objects

[Peter Brown]

Hi,

I'm building a JSON API on top of OrientDB using Pacer, and was curious if anyone had any suggestions for how to handle this situation. My application has 3 main types of objects, Project, Device, and Measurement. A project is the root of all relationships, and can have many devices. Each device can be attached to other devices through a similar "has many" relationship and every device has many measurements. If I were building this in a relational database with ActiveRecord, it would be something like this (ignoring the device-to-device relationship):

class Project < AR::Base

  has_many :devices

end

class Device < AR::Base

  has_many :measurements

  belongs_to :project

end

class Measurement < AR::Base

  belongs_to :device

end

Is there is a best practices way to represent this relationship as a nested JSON object? I'm new to graph databases and wasn't sure if I'm missing some fundamental concept with graphs or Pacer. Right now I'm handling it by defining an as_json method on both the Route and Vertex modules which just returns the properties object. Then in my controller, I'm basically merging all the objects together manually:

json = project.as_json.merge(

  devices: devices.to_a.map { |device|

    device.as_json.merge(measurements: device.measurements.to_a.as_json)

  }

)