Request.hs

-- Copyright (c) 2010, Diego Souza
-- All rights reserved.
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module Yql.Core.LocalFunctions.Request
       ( function
       , jsonFunction
       , diagnosticsFunction
       , endpointFunction
       ) where

import Yql.Core.Types
import Yql.Core.LocalFunction
import Network.OAuth.Http.Request as R

function :: Exec
function = Before doc func
  where doc link = unlines [ "Modify the request query string"
                           , "Example:"
                           , "  SELECT * FROM foobar | " ++ link ++ "(format=\"json\")"
                           , "  SELECT * FROM foobar | " ++ link ++ "(diagnostics=\"true\")"
                           , "  SELECT * FROM foobar | " ++ link ++ "(_maxage=3600)"
                           ]
        
        func vs r = r { qString = foldr R.insert (qString r) params }
          where params = map (\(k,v) -> (k,myShow v)) vs
                
                myShow (TxtValue v) = v
                myShow v            = show v

jsonFunction :: Exec
jsonFunction = Before doc func
  where doc _ = unlines [ "Changes the output format to json."
                        ]
        
        func _ r = r { qString = R.insert ("format","json") (qString r) }

diagnosticsFunction :: Exec
diagnosticsFunction = Before doc func
  where doc _ = unlines [ "Sends diagnostics=true parameter to yql"
                        ]
        
        func _ r = r { qString = R.insert ("diagnostics","true") (qString r) }

endpointFunction :: Exec
endpointFunction = Before doc func
  where doc link = unlines [ "Allow you to change the yql endpoint"
                           , "Examples:"
                           , " SELECT * FROM foobar | " ++ link ++ "(host=\"query.yahooapis.com\", port=80);"
                           ]
        
        func vs r = r { host = newHost (host r)
                      , port = newPort (port r)
                      }
                    
          where newHost d = case (lookup "host" vs)
                            of (Just (TxtValue h)) -> h
                               _                   -> d

                newPort d = case (lookup "port" vs)
                            of (Just (NumValue p)) -> read p
                               _                   -> d