50 lines
1.7 KiB
Haskell
50 lines
1.7 KiB
Haskell
{-# LANGUAGE DataKinds #-}
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{-# LANGUAGE DeriveDataTypeable #-}
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{-# LANGUAGE TypeOperators #-}
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{-# LANGUAGE PolyKinds #-}
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module Servant.API.QueryParam (QueryFlag, QueryParam, QueryParams) where
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import Data.Typeable (Typeable)
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import GHC.TypeLits (Symbol)
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-- | Lookup the value associated to the @sym@ query string parameter
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-- and try to extract it as a value of type @a@.
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--
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-- Example:
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--
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-- >>> -- /books?author=<author name>
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-- >>> type MyApi = "books" :> QueryParam "author" Text :> Get '[JSON] [Book]
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data QueryParam (sym :: Symbol) a
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deriving Typeable
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-- | Lookup the values associated to the @sym@ query string parameter
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-- and try to extract it as a value of type @[a]@. This is typically
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-- meant to support query string parameters of the form
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-- @param[]=val1¶m[]=val2@ and so on. Note that servant doesn't actually
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-- require the @[]@s and will fetch the values just fine with
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-- @param=val1¶m=val2@, too.
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--
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-- Example:
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--
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-- >>> -- /books?authors[]=<author1>&authors[]=<author2>&...
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-- >>> type MyApi = "books" :> QueryParams "authors" Text :> Get '[JSON] [Book]
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data QueryParams (sym :: Symbol) a
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deriving Typeable
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-- | Lookup a potentially value-less query string parameter
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-- with boolean semantics. If the param @sym@ is there without any value,
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-- or if it's there with value "true" or "1", it's interpreted as 'True'.
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-- Otherwise, it's interpreted as 'False'.
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--
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-- Example:
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--
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-- >>> -- /books?published
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-- >>> type MyApi = "books" :> QueryFlag "published" :> Get '[JSON] [Book]
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data QueryFlag (sym :: Symbol)
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-- $setup
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-- >>> import Servant.API
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-- >>> import Data.Aeson
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-- >>> import Data.Text
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-- >>> data Book
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-- >>> instance ToJSON Book where { toJSON = undefined }
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