supki / libstackexchange

StackExchange API interface

libstackexchange

Haskell interface to Stack Exchange API v2.1

##Getting started

You talk to StackExchange API server via Requests: quite simple data type containing server host name, API call path, query parameters and so on. Simple request would be like that:

request = questions

Yeah, that simple. Next, Request is a Monoid. This means you can easy construct and reuse arbitrarily complex requests:

common = site "stackoverflow" <> key "12345678"
questions' = questions <> common
answers' = answers <> common

To get response from request, you need to send it to Stack Exchange:

response = askSE $ questions'

Authentication

Some API calls require authentication. The main goal is to get access_token via quite sophisticated process (serverside authentication skeleton example might be helpful here. To get it to work you must provide client_id, redirect_uri and client_secret). After that, you can freely call this priviledged API:

response = askSE $ token "12345678" $ me <> key "12345678"

Retrieving Data

StackExchange responses are, basically, wrapped aeson data structure, so you can access data via ordinary aeson parsers:

ghci> :m + Control.Applicative Data.Aeson Data.Aeson.Types Data.Monoid Data.Text
ghci> data Title = Title Text deriving Show
ghci> instance FromJSON Title where parseJSON o = Title <$> (parseJSON o >>= (.: "title"))
ghci> qs <- askSE $ questions <> site "stackoverflow"
ghci> map (fromJSON . unSE) qs :: [Result Title]
[Success (Title "Playing encrypted video"),Success (Title "How do i get a If statment to read a multilined textbox?"), ...]

Another way for experienced users familiar with lens would be aeson-lens package. For the ease of interaction se Iso is provided:

ghci> import qualified Data.Aeson.Lens as L
ghci> qs ^.. traverse . from se . L.key "title" . L.asText
["Playing encrypted video", "How do i get a If statment to read a multilined textbox?", ...]