Define settings for a Yesod applications. All methods have intelligent defaults, and therefore no implementation is required.

This class is automatically instantiated when you use the template haskell mkYesod function. You should never need to deal with it directly.

A type-safe, concise method of creating breadcrumbs for pages. For each resource, you declare the title of the page and the parent resource (if present).

Gets the title of the current page and the hierarchy of parent pages, along with their respective titles.

How to determine the root of the application for constructing URLs.

Note that future versions of Yesod may add new constructors without bumping the major version number. As a result, you should not pattern match on Approot values.

Responses to indicate some form of an error occurred. These are different from SpecialResponse in that they allow for custom error pages.

Return the same URL if the user is authorized to see it.

Built on top of isAuthorized. This is useful for building page that only contain links to pages the user is allowed to see.

Convert a widget to a PageContent.

The default error handler for errorHandler.

Return an Unauthorized value, with the given i18n message.

Generates a function that takes a Text and logs a LevelDebug message. Usage:

 $(logDebug) "This is a debug log message"

See logDebug

See logDebug

See logDebug

Generates a function that takes a Text and logs a LevelOther message. Usage:

 $(logOther "My new level") "This is a log message"

Generates a function that takes a LogSource and Text and logs a LevelDebug message. Usage:

 $logDebugS "SomeSource" "This is a debug log message"

See logDebugS

See logDebugS

See logDebugS

Generates a function that takes a LogSource, a level name and a Text and logs a LevelOther message. Usage:

 $logOtherS "SomeSource" "My new level" "This is a log message"

Customize the cookies used by the session backend. You may use this function on your definition of makeSessionBackend.

For example, you could set the cookie domain so that it would work across many subdomains:

 makeSessionBackend = fmap (customizeSessionCookie addDomain) ...
   where
     addDomain cookie = cookie { setCookieDomain = Just ".example.com" }

Default: Do not customize anything (id).

Headers to be added to a Result.

Run a HandlerT completely outside of Yesod. This function comes with many caveats and you shouldn't use it unless you fully understand what it's doing and how it works.

As of now, there's only one reason to use this function at all: in order to run unit tests of functions inside HandlerT but that aren't easily testable with a full HTTP request. Even so, it's better to use wai-test or yesod-test instead of using this function.

This function will create a fake HTTP request (both wai's Request and yesod's Request) and feed it to the HandlerT. The only useful information the HandlerT may get from the request is the session map, which you must supply as argument to runFakeHandler. All other fields contain fake information, which means that they can be accessed but won't have any useful information. The response of the HandlerT is completely ignored, including changes to the session, cookies or headers. We only return you the HandlerT's return value.

Format a UTCTime in W3 format.

Format as per RFC 1123.

Format as per RFC 822.

The class of monad transformers. Instances should satisfy the following laws, which state that lift is a transformer of monads:

• lift . return = return

• lift (m >>= f) = lift m >>= (lift . f)

Monads in which IO computations may be embedded. Any monad built by applying a sequence of monad transformers to the IO monad will be an instance of this class.

Instances should satisfy the following laws, which state that liftIO is a transformer of monads:

• liftIO . return = return

• liftIO (m >>= f) = liftIO m >>= (liftIO . f)

A Monad which allows for safe resource allocation. In theory, any monad transformer stack included a ResourceT can be an instance of MonadResource.

Note: runResourceT has a requirement for a MonadBaseControl IO m monad, which allows control operations to be lifted. A MonadResource does not have this requirement. This means that transformers such as ContT can be an instance of MonadResource. However, the ContT wrapper will need to be unwrapped before calling runResourceT.

Since 0.3.0

The WAI application.

A function generating an Html given a URL-rendering function.

Return type of template-reading functions.

render with route interpolation. If using this module standalone, apart from type-safe routes, a dummy renderer can be used:

 renderJavascriptUrl (\_ _ -> undefined) javascriptUrl

When using Yesod, a renderer is generated for you, which can be accessed within the GHandler monad: getUrlRenderParams.

>>> renderCss ([lucius|foo{bar:baz}|] undefined)
"foo{bar:baz}"