Ruby on Rails 5, Active Record Associations, API ONLY

Question

I am working on a react native application and as part of the project I am building an API using Ruby on Rails 5 in API Only mode with ActiveAdmin for the admin interface. I have everything setup, and it's all working well.

I was given the data in a file before having the idea of an API, the structure of which I need to replicate using rails, this is so it can be content manageable.

But I can't seem to get the active record associations correct.

This is a sample of the data file...

{
    name: 'Scottish Stoics',
    days: [
      {
        day: 'Monday',
        meeting: [
          {
            name: 'Meeting one',
            location: 'Test',
            startTime: '11.00',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
          {
            name: 'Meeting two',
            location: 'Test',
            startTime: '10.00',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
          {
            name: 'Meeting three',
            location: 'Test',
            startTime: '10.00',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
        ],
      },
      {
        day: 'Tuesday',
        meeting: [
          {
            name: 'Meeting one',
            location: 'Test',
            startTime: '10',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
          {
            name: 'Meeting two',
            location: 'Test',
            startTime: '10',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
          {
            name: 'Meeting three',
            location: 'Test',
            startTime: '10',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
        ],
      },
    ],
  },
  {
    name: 'Scottish Cycling Group',
    days: [
      {
        day: 'Sunday',
        meeting: [
          {
            name: 'Meeting one',
            location: 'Test',
            startTime: '11.00',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
          {
            name: 'Meeting two',
            location: 'Test',
            startTime: '10.00',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
          {
            name: 'Meeting three',
            location: 'Test',
            startTime: '10.00',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
        ],
      },
      {
        day: 'Tuesday',
        meeting: [
          {
            name: 'Meeting one',
            location: 'Test',
            startTime: '10.00',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
          {
            name: 'Meeting two',
            location: 'Test',
            startTime: '10.00',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
          {
            name: 'Meeting three',
            location: 'Test',
            startTime: '10.00',
            address: 'Test Street',
            meetingLength: '1 Hour',
            city: 'Edinburgh',
          },
        ],
      },
    ],
  }

I have a Group Model, Day Model and a Meeting Model.

Group

 belongs_to :day
 belongs_to :meeting

Meeting

has_many :groups

Day

has_many :groups

And I am getting this result.

[
    {
        id: 1,
        name: "Scottish Stoics",
        created_at: "2018-03-19T11:47:50.818Z",
        updated_at: "2018-04-12T10:50:05.179Z",
        day_id: 7,
        meeting_id: 81
    },
    {
        id: 2,
        name: "Scottish Cycling Group",
        created_at: "2018-03-19T11:47:57.498Z",
        updated_at: "2018-04-11T22:13:26.656Z",
        day_id: 7,
        meeting_id: 83
    },
]

Now I can use jbuilder to get the day name and meeting name which is fine, but what I can't do is select MULTIPLE meetings for one day, and MULTIPLE DAYS for the group. Is this data structure even going to be possible in Rails?

I can't work out if I should be using a different type of association, anyone able to shed some light on this for me?

Answer 1

Assuming that the top level nesting corresponds to Group you can form the associations like that:

Day

has_many :meetings
belongs_to :group

Meeting

belongs_to :day

Group

has_many :days
has_many :meetings, through: :days

Though i have the impression that in the JSON provided it should be meetings rather than meeting to keep it RESTful