Safe Haskell | None |
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Utility functions for using Fay from a Yesod application.
This module is intended to be used from your Yesod application, not from your Fay programs.
We assume a specific file structure, namely that there is a fay
folder
containing client-side code, and fay-shared
containing code to be used by
both the client and server.
The Language.Fay.Yesod
module (part of this package) is
required by both client and server code. However, since Fay does not
currently have package management support, we use a bit of a hack: the TH
calls in this package will automatically create the necessary
fay/Language/Fay/Yesod.hs
file. Ultimately, we will use a more elegant
solution.
In the future, if this package proves popular enough, Fay support will likely be built into the scaffolding. In the meantime, you must manually integrate it. In order to take advantage of this module, you should modify your Yesod application as follows:
- Modify your
cabal
file to include thefay-shared
folder when compiling. This can be done by adding ahs-source-dirs: ., fay-shared
line to your library section. - Create the module
SharedTypes
infay-shared
and create aCommand
datatype. For an example of what this file should look like, see https://github.com/snoyberg/yesod-fay/blob/master/sample/fay-shared/SharedTypes.hs. - Add the function
fayFile
to yourImport
module. See https://github.com/snoyberg/yesod-fay/blob/master/sample/Import.hs for an example. - Add a new route at for the Fay subsite. Generally, it will look like
/fay-command FaySiteR FaySite getFaySite
. - Import the
SharedTypes
andYesod.Fay
modules into yourFoundation.hs
module. Add an instance ofYesodFay
for your application. You should set theYesodFayCommand
associated type to theCommand
datatype you created. (You may also need to add aYesodJquery
instance.) Note that this instance must appear after yourparseRoutes
. Set the methodfayRoute
toFaySiteR
(or whatever you called the subsite route), and implementyesodFayCommand
. It will generally look something likeyesodFayCommand render command = case command of { ... }
. - In order to use Fay, add
$(fayFile "MyModule")
to a widget, and then write the correspondingfay/MyModule.hs
file. For an example, see https://github.com/snoyberg/yesod-fay/blob/master/sample/fay/Home.hs.
- class (Data (YesodFayCommand master), Read (YesodFayCommand master), Foreign (YesodFayCommand master), YesodJquery master) => YesodFay master where
- type YesodFayCommand master
- yesodFayCommand :: CommandHandler master master
- fayRoute :: Route FaySite -> Route master
- fayFileProd :: FayFile
- fayFileReload :: FayFile
- type FayFile = String -> Q Exp
- type CommandHandler sub master = forall s. (forall a. Show a => Returns a -> a -> GHandler sub master s) -> YesodFayCommand master -> GHandler sub master s
- data Returns a
- data FaySite
- getFaySite :: a -> FaySite
- class YesodJquery a where
- urlJqueryJs :: a -> Either (Route a) Text
- urlJqueryUiJs :: a -> Either (Route a) Text
- urlJqueryUiCss :: a -> Either (Route a) Text
- urlJqueryUiDateTimePicker :: a -> Either (Route a) Text
Typeclass
class (Data (YesodFayCommand master), Read (YesodFayCommand master), Foreign (YesodFayCommand master), YesodJquery master) => YesodFay master whereSource
Type class for applications using Fay.
We depend on YesodJquery
since the generated client-side code uses jQuery
for making Ajax calls. We have an associated type stating the command
datatype. Since this datatype must be used by both the client and server,
you should place its definition in the fay-shared
folder.
type YesodFayCommand master Source
The command type. This type must be shared between client and server
code, and should therefore be placed somewhere in fay-shared
. The last
field for each data constructor must be of type Returns
, with a type
parameter specify the actual return type. For example:
data Command = GetFib Int (Returns Int)
yesodFayCommand :: CommandHandler master masterSource
User-defined function specifying how to respond to commands. Using the above datatype, this might look like:
yesodFayCommand render command = case command of GetFib index r = render r $ fibs !! index
fayRoute :: Route FaySite -> Route masterSource
Where in the routing tree our Fay subsite is located. This is
generally named FaySiteR
, e.g.:
mkYesod "YourSite" [parseRoutes ... /fay-command FaySiteR FaySite getFaySite |] instance YesodFay YourSite where fayRoute = FaySiteR
Include Fay programs
Does a full compile of the Fay code via GHC for type checking, and then embeds the Fay-generated Javascript as a static string. File changes during runtime will not be reflected.
fayFileReload :: FayFileSource
Performs no type checking on the Fay code. Each time the widget is requested, the Fay code will be compiled from scratch to Javascript.
type FayFile = String -> Q ExpSource
A function that takes a String giving the Fay module name, and returns an
TH splice that generates a Widget
.
Commands
type CommandHandler sub master = forall s. (forall a. Show a => Returns a -> a -> GHandler sub master s) -> YesodFayCommand master -> GHandler sub master sSource
A function provided by the developer describing how to answer individual commands from client-side code.
Due to restrictions of the type system in Fay, we use a relatively simple
approach for encoding the return type. In order to specify this, an extra
parameter- Returns
- is passed around, with a phantom type variable stating
the expected return type.
The first argument to your function is the "respond" function: it takes
the extra Returns
parameter as well as the actual value to be returned,
and produces the expected result.
A proxy type for specifying what type a command should return. The final
field for each data constructor in a command datatype should be Returns
.
Subsite
The Fay subsite.
getFaySite :: a -> FaySiteSource
To be used from your routing declarations.
Reexports
class YesodJquery a where
urlJqueryJs :: a -> Either (Route a) Text
The jQuery Javascript file. Note that in upgrades to this library, the version of jQuery referenced, or where it is downloaded from, may be changed without warning. If you are relying on a specific version of jQuery, you should give an explicit URL instead of relying on the default value.
Currently, the default value is jQuery 1.7 from Google's CDN.
urlJqueryUiJs :: a -> Either (Route a) Text
The jQuery UI 1.8 Javascript file.
urlJqueryUiCss :: a -> Either (Route a) Text
The jQuery UI 1.8 CSS file; defaults to cupertino theme.
urlJqueryUiDateTimePicker :: a -> Either (Route a) Text
jQuery UI time picker add-on.