JSON, Aeson and Template Haskell for fun and profit

Event.hs

{-# LANGUAGE OverloadedStrings #-}

module Meetup.Types.Event where

import Data.Text
import Data.Aeson
import Control.Applicative  ((<$>), (<*>))
import Control.Monad        (mzero)
import Data.ByteString.Lazy

data Event = Event { name        :: Text
		   , created     :: Int
		   , event_url   :: Text
		   } deriving (Show, Eq)

instance FromJSON Event where
  parseJSON (Object v) = Event
                          <$> v .: "name"
                          <*> v .: "created"
                          <*> v .: "event_url"
  parseJSON _          = mzero


-- Sample

sampleEvent = do
	sample_event_json <- Data.ByteString.Lazy.readFile "responses/event.json"
	let event = decode sample_event_json :: Maybe Event
	return event

event.json

{
   "visibility" : "public",
   "waitlist_count" : 0,
   "time" : 1399939200000,
   "status" : "upcoming",
   "yes_rsvp_count" : 11,
   "group" : {
      "group_lat" : 42.9799995422363,
      "who" : "UI Professionals",
      "join_mode" : "open",
      "urlname" : "HTML5-Milwaukee",
      "name" : "HTML5 Milwaukee",
      "group_lon" : -87.8899993896484,
      "id" : 4130942
   },
   "utc_offset" : -18000000,
   "event_url" : "http://www.meetup.com/HTML5-Milwaukee/events/173163622/",
   "updated" : 1397848994000,
   "id" : "173163622",
   "headcount" : 0,
   "name" : "HTML5 App Start to Finish : Pt 2 : observables, live binding, charts & grids",
   "duration" : 4500000,
   "rsvp_limit" : 35,
   "description" : "<p>Part 2  of this series will focus on building page components with observable data structures, server data models, application state and simple live binding.  </p> <p>Please bring a laptop as we will be doing a 50/50 panel and work session.</p> <p><br/>Keeping an application state object helps track user selections and can be bound to a data model for easy server persistence. We'll show a simple CRUD api for this with a mock up backend in NodeJS.</p> <p><br/>Using Observable objects allow you to get progressive updates to a dataset and signal those changes to your page controls. Live bound page components will update themselves when your observable data changes. We'll be building a grid and a simple chart using D3 and <a href=\"http://canjs.com/\">CanJS</a> <a href=\"http://canjs.com/docs/can.Component.html\">can.Component</a> web component tooling.</p> <p>Please install NodeJS and <a href=\"http://git-scm.com/\">Git</a> (or the Github application for <a href=\"https://mac.github.com/\">Mac</a> or <a href=\"https://windows.github.com/\">Windows</a>) for your platform before you arrive. You can clone <a href=\"https://github.com/shcarrico/skel-html5\"><a href=\"https://github.com/shcarrico/skel-html5\" class=\"linkified\">https://github.com/shcarrico/skel-html5</a></a> and follow the readme.md for installation directions to get the sample app up and running. I will be making changes to the sample repo up to the meetup day, so check back for new stuff ~ day or so ahead of time.</p>",
   "created" : 1395693245000,
   "venue" : {
      "country" : "us",
      "lat" : 43.051735,
      "name" : "Corvisa Services",
      "address_1" : "1610 North 2nd Street #101",
      "state" : "WI",
      "city" : "Milwaukee",
      "zip" : "53212",
      "id" : 11046872,
      "lon" : -87.912354,
      "repinned" : false
   },
   "maybe_rsvp_count" : 0
}

RSVP.hs

{-# LANGUAGE OverloadedStrings,TemplateHaskell #-}

module Meetup.Types.RSVP where

import Data.Aeson
import Data.Aeson.TH
import qualified Data.Text as T
import qualified Data.ByteString.Lazy as BL

data RSVP = RSVP { response :: T.Text
		 , created  :: Int
		 } deriving (Show, Eq)

$(deriveJSON defaultOptions ''RSVP)

sampleRSVP = do
	sample_event_json <- BL.readFile "responses/rsvp.json"
	let rsvp = decode sample_event_json :: Maybe RSVP
	return rsvp

rsvp.json

{
   "rsvp_id" : 1203820722,
   "mtime" : 1395693245000,
   "member_photo" : {
      "photo_id" : 59311832,
      "thumb_link" : "http://photos3.meetupstatic.com/photos/member/7/c/5/8/thumb_59311832.jpeg",
      "photo_link" : "http://photos1.meetupstatic.com/photos/member/7/c/5/8/member_59311832.jpeg"
   },
   "member" : {
      "member_id" : 51992492,
      "name" : "Stan Carrico"
   },
   "response" : "yes",
   "event" : {
      "time" : 1399939200000,
      "name" : "HTML5 App Start to Finish : Pt 2 : observables, live binding, charts & grids",
      "event_url" : "http://www.meetup.com/HTML5-Milwaukee/events/173163622/",
      "id" : "173163622"
   },
   "created" : 1395693245000,
   "group" : {
      "group_lat" : 42.9799995422363,
      "join_mode" : "open",
      "urlname" : "HTML5-Milwaukee",
      "group_lon" : -87.8899993896484,
      "id" : 4130942
   },
   "guests" : 0,
   "venue" : {
      "country" : "us",
      "lat" : 43.051735,
      "name" : "Corvisa Services",
      "address_1" : "1610 North 2nd Street #101",
      "state" : "WI",
      "city" : "Milwaukee",
      "zip" : "53212",
      "id" : 11046872,
      "lon" : -87.912354,
      "repinned" : false
   }
}