Book Errata

There have been some minor changes to Yesod since the publication of the book. This page will hopefully contain a full list:

• To ease installation, we now have a yesod-platform package. Instead of running cabal install yesod, you can run cabal install yesod-platform.

• Hamlet now requires that all tags have a closing right bracket. In other words:

  <good>
  <bad
  

• The function yepnopeJs has been generalized to jsLoader. Similarly, encryptKey and clientSessionDuration have been replaced with makeSessionBackend.

• Persistent no longer automatically derives Show, Read, and Eq instances. You must manually add them in. For example:

  Person
      name Text
      age Int
      deriving Show -- this is now required