Flat resource into nested resource?

[state-developer]

I have a Rails active record that looks like this:

membership_number: 12988,
member_name: Terry Bradshaw,
member_address1: 5555 West Test,
member_city: Miami,
member_state: FL

I'm trying to figure out how to transform the object into something a 3rd party API needs (like this):

{
  "number": 12988,
  "member": {
    "name": "Terry Bradshaw",
    "address:" {
      "line1:" "5555 West Test",
      "city": "Miami",
      "state": "FL"
     }
  }
}

Changing the membership_number to number is easy enough. However, I'm getting stuck trying to create the nested part of the JSON from the active record object. I've tried one and various other ways of doing, like creating a MemberNameResource and MemberAddressResource, but nothing I've tried seems to work.

Here is an example of what I've tried, but it didn't seem to work (simplified):

class MemberResource
  include Alba::Resource
  
  attribute :number, :&membership_number
  attributes :member
  
  def member(resource)
    MemberNameResource.new({ resource.slice('member_name') }).to_h
  end
end

class MemberNameResource
  include Alba::Resource
  
  attributes :name, :&member_name
end

Any suggestions?

[state-developer]

Think I found a solution:

class MemberResource
  include Alba::Resource
  
  attribute :number, :&membership_number
  
  attribute :member do |resource|
    MemberNameResource(resource).to_h
  end
end

class MemberNameResource
  include Alba::Resource
  
  attributes :name, :&member_name
end

Hope that helps anyone else trying to do the same thing.

[okuramasafumi]

Hi @state-developer I think you can use compose_of method to aggregate member data, that makes to implement API with Alba much easier.

If we don't want to use compose_of, the code will look like this:

class MemberAddressResource
  include Alba::Resource

  attribute :lines, &:member_address1
  attribute :city, &:member_city
  attribute :state, &:member_state
end

class MemberInnerResource
  include Alba::Resource

  attribute :name, &:member_name
  attribute :address do |inner|
    MemberAddressResource.new(inner).to_h
  end
end

class MemberResource
  include Alba::Resource

  attribute :number, &:membership_number
  attribute :member do |foo|
    MemberInnerResource.new(foo).to_h
  end
end

Alba currently doesn't have an API to define nested hash easily. If we need it so much I think we should implement it.

[state-developer]

Yes. This is what I ended up doing. Thanks!