Network.Wai.Middleware.Catch

Exception handling for Wai and Warp.

By default Warp not handles exceptions well. It just log them to console. This package - an attempt to solve the problem.

The only drawback stems from the basic advantages of Haskell - laziness. All errors within Wai ResponseBuilder will not be caught. Thus, the following code will not work:

 ... return $ responseLBS undefined ...

To ensure catch all errors, you need to consume all data before feeding the builder.

Documentation

data ResponseHandler

Handler wrapper. For polymorphic exceptions.

Constructors

forall e . Exception e => ResponseHandler (e -> Application)

protect

Arguments

:: [ResponseHandler]

Wrapped handlers. See mkHandler.

-> Middleware

Protect Middleware chain from exceptions. This acts like catches, but uses own handler type for simplicity.

mkHandler

Arguments

:: forall e . Exception e

=> (e -> Application)

-> ResponseHandler

Helper for make RequestHandler

 protect [mkHandler myHandler] $ ...

defHandler :: ResponseHandler

Default handler.