The basic typeclass for a Yesod application.
- class Eq (Route a) => Yesod a where
- approot :: a -> String
- encryptKey :: a -> IO Key
- clientSessionDuration :: a -> Int
- errorHandler :: ErrorResponse -> GHandler sub a ChooseRep
- defaultLayout :: GWidget sub a () -> GHandler sub a RepHtml
- onRequest :: GHandler sub a ()
- urlRenderOverride :: a -> Route a -> Maybe String
- isAuthorized :: Route a -> Bool -> GHandler s a AuthResult
- isWriteRequest :: Route a -> GHandler s a Bool
- authRoute :: a -> Maybe (Route a)
- splitPath :: a -> ByteString -> Either ByteString [String]
- joinPath :: a -> String -> [String] -> [(String, String)] -> String
- addStaticContent :: String -> String -> ByteString -> GHandler sub a (Maybe (Either String (Route a, [(String, String)])))
- sessionIpAddress :: a -> Bool
- class Eq (Route y) => YesodSite y where
- class Eq (Route s) => YesodSubSite s y where
- class YesodPersist y where
- module Database.Persist
- get404 :: (PersistBackend (t m), PersistEntity val, Monad (t m), Failure ErrorResponse m, MonadTrans t) => Key val -> t m val
- class YesodBreadcrumbs y where
- breadcrumbs :: YesodBreadcrumbs y => GHandler sub y (String, [(Route y, String)])
- maybeAuthorized :: Yesod a => Route a -> Bool -> GHandler s a (Maybe (Route a))
- widgetToPageContent :: (Eq (Route master), Yesod master) => GWidget sub master () -> GHandler sub master (PageContent (Route master))
- defaultLayoutJson :: Yesod master => GWidget sub master () -> Json -> GHandler sub master RepHtmlJson
- redirectToPost :: Route master -> GHandler sub master a
- defaultErrorHandler :: Yesod y => ErrorResponse -> GHandler sub y ChooseRep
- data AuthResult
Type classes
class Eq (Route a) => Yesod a whereSource
Define settings for a Yesod applications. The only required setting is
approot
; other than that, there are intelligent defaults.
An absolute URL to the root of the application. Do not include trailing slash.
If you want to be lazy, you can supply an empty string under the following conditions:
- Your application is served from the root of the domain.
- You do not use any features that require absolute URLs, such as Atom feeds and XML sitemaps.
encryptKey :: a -> IO KeySource
The encryption key to be used for encrypting client sessions.
clientSessionDuration :: a -> IntSource
Number of minutes before a client session times out. Defaults to 120 (2 hours).
errorHandler :: ErrorResponse -> GHandler sub a ChooseRepSource
Output error response pages.
defaultLayout :: GWidget sub a () -> GHandler sub a RepHtmlSource
Applies some form of layout to the contents of a page.
onRequest :: GHandler sub a ()Source
Gets called at the beginning of each request. Useful for logging.
urlRenderOverride :: a -> Route a -> Maybe StringSource
Override the rendering function for a particular URL. One use case for this is to offload static hosting to a different domain name to avoid sending cookies.
:: Route a | |
-> Bool | is this a write request? |
-> GHandler s a AuthResult |
Determine if a request is authorized or not.
Return Nothing
is the request is authorized, Just
a message if
unauthorized. If authentication is required, you should use a redirect;
the Auth helper provides this functionality automatically.
isWriteRequest :: Route a -> GHandler s a BoolSource
Determines whether the current request is a write request. By default, this assumes you are following RESTful principles, and determines this from request method. In particular, all except the following request methods are considered write: GET HEAD OPTIONS TRACE.
This function is used to determine if a request is authorized; see
isAuthorized
.
authRoute :: a -> Maybe (Route a)Source
The default route for authentication.
Used in particular by isAuthorized
, but library users can do whatever
they want with it.
splitPath :: a -> ByteString -> Either ByteString [String]Source
A function used to split a raw PATH_INFO value into path pieces. It
returns a Left
value when you should redirect to the given path, and a
Right
value on successful parse.
By default, it splits paths on slashes, and ensures the following are true:
- No double slashes
- If the last path segment has a period, there is no trailing slash.
- Otherwise, ensures there is a trailing slash.
joinPath :: a -> String -> [String] -> [(String, String)] -> StringSource
Join the pieces of a path together into an absolute URL. This should
be the inverse of splitPath
.
:: String | filename extension |
-> String | mime-type |
-> ByteString | content |
-> GHandler sub a (Maybe (Either String (Route a, [(String, String)]))) |
This function is used to store some static content to be served as an external file. The most common case of this is stashing CSS and JavaScript content in an external file; the Yesod.Widget module uses this feature.
The return value is Nothing
if no storing was performed; this is the
default implementation. A Just
Left
gives the absolute URL of the
file, whereas a Just
Right
gives the type-safe URL. The former is
necessary when you are serving the content outside the context of a
Yesod application, such as via memcached.
sessionIpAddress :: a -> BoolSource
Whether or not to tie a session to a specific IP address. Defaults to
True
.
class Eq (Route y) => YesodSite y whereSource
This class is automatically instantiated when you use the template haskell mkYesod function. You should never need to deal with it directly.
class Eq (Route s) => YesodSubSite s y whereSource
Same as YesodSite
, but for subsites. Once again, users should not need
to deal with it directly, as the mkYesodSub creates instances appropriately.
YesodSubSite Static master | |
(Yesod master, Item item, SinglePiece (Key item), ToForm item master) => YesodSubSite (Crud master item) master |
Persistence
class YesodPersist y whereSource
module Database.Persist
get404 :: (PersistBackend (t m), PersistEntity val, Monad (t m), Failure ErrorResponse m, MonadTrans t) => Key val -> t m valSource
Breadcrumbs
class YesodBreadcrumbs y whereSource
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).
breadcrumbs :: YesodBreadcrumbs y => GHandler sub y (String, [(Route y, String)])Source
Gets the title of the current page and the hierarchy of parent pages, along with their respective titles.
Utitlities
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.
widgetToPageContent :: (Eq (Route master), Yesod master) => GWidget sub master () -> GHandler sub master (PageContent (Route master))Source
Convert a widget to a PageContent
.
defaultLayoutJson :: Yesod master => GWidget sub master () -> Json -> GHandler sub master RepHtmlJsonSource
Provide both an HTML and JSON representation for a piece of data, using
the default layout for the HTML output (defaultLayout
).
redirectToPost :: Route master -> GHandler sub master aSource
Redirect to a POST resource.
This is not technically a redirect; instead, it returns an HTML page with a POST form, and some Javascript to automatically submit the form. This can be useful when you need to post a plain link somewhere that needs to cause changes on the server.
Defaults
defaultErrorHandler :: Yesod y => ErrorResponse -> GHandler sub y ChooseRepSource
The default error handler for errorHandler
.