Using has_many with differing JSON root object names

[samstarling]

Hey @edtjones @remiprev – I'm having some issues with has_many and parse_root_in_json. The API I'm working with looks a bit like this:

GET /users/1       { user: { name: peter } }
GET /users/1/items { items: [ { name: apple }, { name: orange } ] }
GET /items/1       { item: { name: apple } }

My classes are like this:

class User
  include Her::Model
  parse_root_in_json :client
  has_many :items
end

class Item
  include Her::Model
  parse_root_in_json :item
end

However, when I call User.find(1).items, I get this error:

undefined method `each' for #<Item:0x007faf89dc3cb0>

Is there something I'm doing wrong here? Can I make this one class work properly? Thanks!

[zacharywelch]

Hi @samstarling, parse_root_in_json expects arrays to be returned as

GET /users/1/items  #=> [{ item: { id: 1, name: "apple" } }]

If there's a root element on the array you should be able to use the active_model_serializers format

GET /users/1/items  #=> { items: [{ item: { id: 1, name: "apple" } }] }
GET /users/1/items  #=> { items: [{ id: 1, name: "apple" }] }

class Item
  include Her::Model
  parse_root_in_json true, format: :active_model_serializers
end

Hope this helps 😺

[samstarling]

@zacharywelch Aha, that makes perfect sense. I'll give that a go! Thanks for the speedy reply. I'm also having problems parsing responses like this:

{
  client: {
    name: Sam,
    surname: Starling
  },
  addresses: [
    foo: bar
  ]
}

I'm trying to parse this with a standard Her::Model class called Client and using format: :active_model_serializers, but I think I lose access to addresses.

[zacharywelch]

client and addresses are at the same level and considered two distinct resources. Do you have control over the api where you could return something along the lines of?

{
  client: {
    name: "Sam",
    surname: "Sterling",
    addresses: [{ line1: "123 Sesame St" }]
  }
}

[samstarling]

@zacharywelch Sadly I don't have any control over this API, so if there was any other way around this, that would be really useful to know about. I had a dig through the source code, but couldn't see much of a way forward. Thanks in advance for any advice!

[edtjones]

@samstarling I've taken to massaging the incoming json for APIs like this in a middleware. Here, for example, is a middleware to take Zoho CRM's json and turn it into something Her will understand: https://github.com/errorstudio/zoho-ruby/blob/master/lib/zoho/crm/middleware/response_parser_middleware.rb

You wouldn't have to do much rework on the incoming json in your case. My example is a bit bananas.

[edtjones]

(and here is where you invoke the middleware in the Her setup - https://github.com/errorstudio/zoho-ruby/blob/master/lib/zoho/crm/crm.rb#L30 )

[samstarling]

@edtjones Oh nice – that looks like a good solution. The API I'm working with has a slightly odd format for errors as well, so I think this provides a nice solution for that too. I'll give it a go, thanks!

[zacharywelch]

Going to close the issue now that we have a solution. Thanks again 😺