b8e917e · typeable/aeson

git.iko.soy/typeable/aeson

on master help sign in

Add defaultObjectWithType and improve documentation

b8e917eBas van Dijk14 years ago

Data/Aeson/TH.hs+35−17

compare with master

unifiedsplit

@@ -27,12 +27,13 @@ data D a = Nullary

27 } deriving Eq

28@

30−Next we derive the necessary instances. Note that we make use of the feature to

30+Next we derive the necessary instances. Note that we make use of the

31−change record field names. In this case we drop the first 4 characters of every

31+feature to change record field names. In this case we drop the first 4

32−field name.

32+characters of every field name. We also modify constructor names by

33+lower-casing them:

34@

35@

35−$('deriveJSON' 'defaultOptions'{'fieldNameModifier' = 'drop' 4} ''D)

36+$('deriveJSON' 'defaultOptions'{'fieldNameModifier' = 'drop' 4, 'constructorNameModifier' = map toLower} ''D)

36@

37@

38Now we can use the newly created instances.

39Now we can use the newly created instances.

@@ -58,7 +59,7 @@ $('deriveJSON' 'defaultOptions' ''(,,,))

58-}

59-}

60module Data.Aeson.TH

61module Data.Aeson.TH

61− ( Options(..), SumEncoding(..), defaultOptions

62+ ( Options(..), SumEncoding(..), defaultOptions, defaultObjectWithType

63 , deriveJSON

64 , deriveJSON

@@ -136,24 +137,27 @@ data Options = Options

136data SumEncoding =

137data SumEncoding =

137 TwoElemArray -- ^ A constructor will be encoded to a 2-element

138 TwoElemArray -- ^ A constructor will be encoded to a 2-element

138 -- array where the first element is the name of the

139 -- array where the first element is the name of the

140+ -- constructor (modified by the

139− -- constructor and the second element the content of

141+ -- 'constructorNameModifier') and the second element

140− -- the constructor.

142+ -- the content of the constructor.

141 | ObjectWithType { typeFieldName :: String

143 | ObjectWithType { typeFieldName :: String

142 , valueFieldName :: String

144 , valueFieldName :: String

143 }

145 }

144 -- ^ A constructor will be encoded to an object with a field

146 -- ^ A constructor will be encoded to an object with a field

145− -- 'typeFieldName' which specifies the constructor name. If the

147+ -- 'typeFieldName' which specifies the constructor name (modified

148+ -- by the 'constructorNameModifier'). If the constructor is not a

146− -- constructor is not a record the constructor content will be

149+ -- record the constructor content will be stored under the

147− -- stored under the 'valueFieldName' field.

150+ -- 'valueFieldName' field.

148 | ObjectWithSingleField

151 | ObjectWithSingleField

149 -- ^ A constructor will be encoded to an object with a single

152 -- ^ A constructor will be encoded to an object with a single

150− -- field named after the constructor and the value will be the

153+ -- field named after the constructor (modified by the

154+ -- 'constructorNameModifier') and the value will be the contents

151− -- contents of the constructor.

155+ -- of the constructor.

152−

156+

153−-- | Default encoding options which specify to not modify field names,

157+-- | Default encoding options which specify to not modify field and

154−-- encode the constructors of a datatype with all nullary constructors

158+-- constructor names, encode the constructors of a datatype with all

155−-- to just strings with the name of the constructor and use a

159+-- nullary constructors to just strings with the name of the

156−-- 2-element array for other sum datatypes.

160+-- constructor and use a 2-element array for other sum datatypes.

157defaultOptions :: Options

161defaultOptions :: Options

158defaultOptions = Options

162defaultOptions = Options

159 { fieldNameModifier = id

163 { fieldNameModifier = id

@@ -162,6 +166,20 @@ defaultOptions = Options

162 , sumEncoding = TwoElemArray

166 , sumEncoding = TwoElemArray

163 }

167 }

164

168

169+-- | Note that:

170+--

171+-- @

172+-- defaultObjectWithType = 'ObjectWithType'

173+-- { 'typeFieldName' = \"type\"

174+-- , 'valueFieldName' = \"value\"

175+-- }

176+-- @

177+defaultObjectWithType :: SumEncoding

178+defaultObjectWithType = ObjectWithType

179+ { typeFieldName = "type"

180+ , valueFieldName = "value"

181+ }

182+

165--------------------------------------------------------------------------------

183--------------------------------------------------------------------------------

166-- Convenience

184-- Convenience

167--------------------------------------------------------------------------------

185--------------------------------------------------------------------------------