DBResponse.purs

module DBResponse where

import Prelude 

import Data.Foreign
import Data.Foreign.Class

data Doc a = Doc { doc :: a }
data CustomerResp = CustomerResp { rows :: Array (Doc Customer) }
data Customer = Customer { 
    alias  :: String
  , dalias :: String
  , name   :: String
}

instance custRespIsForeign::IsForeign CustomerResp where
  read value = do
    rows <- readProp "rows" value
    pure $ CustomerResp { rows }

instance custDocIsForeign::IsForeign (Doc Customer) where
  read value = do
    doc <- readProp "doc" value
    pure $ (Doc doc)

instance customerIsForeign::IsForeign Customer where 
  read value = do
    alias  <- readProp "alias"  value
    dalias <- readProp "dalias" value
    name   <- readProp "name"   value
    pure $ Customer {alias, dalias, name}

readCustomer json = 
  readJSON json :: F CustomerResp

gistfile1.txt

  No type class instance was found for
    Data.Foreign.Class.IsForeign { doc :: Customer }
in value declaration custDocIsForeign

response.json

{
  "rows": [
    {
      "id": "customer:foobar",
      "doc": {
        "alias": "foobar",
        "dalias": "foobar",
        "name": "Foobar",
      }
    }
  ]
}