1.2 upgrade

The Detailed change list and the Changelog have an overview of the changes. The release announcement explains some of the changes.

Scaffolding

• Changes to combine static assets

Experience reports

https://plus.google.com/118323070335349339293/posts/JxZ2jpW8CfX

Sample patches

DtekPortalen

Changes

• change the cabal file to yesod >= 1.2 and bump any persistent dependencies to >= 1.2
• run cabal update && cabal install --force-reinstalls
• most changes are visible in the commit that updates the scaffolding code for Yesod 1.2
• change sqlSettings to sqlOnlySettings (details here)

Persistent

• change persistent imports:

-import qualified Database.Persist.Store
+import qualified Database.Persist
-import Database.Persist.GenericSql
+import Database.Persist.Sql

• change the persist quasi-quoter to persistUpperCase.
• add deriving Typeable to any entities that trigger a compile-time error referring to generics. See this patch

Yesod

• Couldn't match expected type RepJson' with actual type Value'

-getJsonR :: Handler RepJson
-getJsonR = jsonToRepJson $ object ["message" .= ("Hello, World!" :: Text)]
+getJsonR :: Handler Value
+getJsonR = return $ object ["message" .= ("Hello, World!" :: Text)]

• For multiple representation types, use selectRep/provideRep and Handler TypedContent