yesod-examples 0.5.0 → 0.5.0.1

raw patch · 3 files changed

+129/−2 lines, 3 filesdep +timedep ~yesodnew-component:exe:formnew-component:exe:mkToForm

Dependencies added: time

Dependency ranges changed: yesod

Files

• yesod-examples.cabal +9/−2
• yesod/tutorial/form.lhs +48/−0
• yesod/tutorial/mkToForm.hs +72/−0

@@ -1,5 +1,5 @@ Name:                yesod-examples-Version:             0.5.0+Version:             0.5.0.1 Synopsis:            Example programs using the Yesod Web Framework. Description:         These are the same examples and tutorials found on the documentation site. Homepage:            http://docs.yesodweb.com/@@ -17,7 +17,7 @@ Executable helloworld   Main-is:             yesod/helloworld.lhs   Build-depends:       base >= 4 && < 5,-                       yesod >= 0.5.0 && < 0.6+                       yesod >= 0.5.0.1 && < 0.6  Executable blog   Main-is:             yesod/tutorial/blog.lhs@@ -42,6 +42,13 @@  Executable widgets   Main-is:             yesod/tutorial/widgets.lhs++Executable form+  Main-is:             yesod/tutorial/form.lhs++Executable mkToForm+  Main-is:             yesod/tutorial/mkToForm.hs+  Build-depends:       time  Executable persistent-synopsis   Main-is:             persistent/synopsis.lhs

@@ -0,0 +1,48 @@+Forms can be a tedious part of web development since they require synchronization of code in many different areas: the HTML form declaration, parsing of the form and reconstructing a datatype from the raw values. The Yesod form library simplifies things greatly. We'll start off with a basic application.+++> {-# LANGUAGE TypeFamilies, QuasiQuotes, OverloadedStrings #-}+> import Yesod+> import Control.Applicative+> data FormExample = FormExample+> type Handler = GHandler FormExample FormExample+> mkYesod "FormExample" [$parseRoutes|+> / RootR GET+> |]+> instance Yesod FormExample where approot _ = ""++Next, we'll declare a Person datatype with a name and age. After that, we'll create a formlet. A formlet is a declarative approach to forms. It takes a Maybe value and constructs either a blank form, a form based on the original value, or a form based on the values submitted by the user. It also attempts to construct a datatype, failing on validation errors.++> data Person = Person { name :: String, age :: Int }+>     deriving Show+> personFormlet p = fieldsToTable $ Person+>     <$> stringField "Name" (fmap name p)+>     <*> intField "Age" (fmap age p)++We use an applicative approach and stay mostly declarative. The "fmap name p" bit is just a way to get the name from within a value of type "Maybe Person".++> getRootR :: Handler RepHtml+> getRootR = do+>     (res, wform, enctype) <- runFormGet $ personFormlet Nothing++We use runFormGet to bind to GET (query-string) parameters; we could also use runFormPost. The "Nothing" is the initial value of the form. You could also supply a "Just Person" value if you like. There is a three-tuple returned, containing the parsed value, the HTML form as a widget and the encoding type for the form.++We use a widget for the form since it allows embedding CSS and Javascript code in forms directly. This allows unobtrusive adding of rich Javascript controls like date pickers.++>     defaultLayout $ do+>         setTitle "Form Example"+>         form <- extractBody wform++extractBody returns the HTML of a widget and "passes" all of the other declarations (the CSS, Javascript, etc) up to the parent widget. The rest of this is just standard Hamlet code and our main function.++>         addBody [$hamlet|+> %p Last result: $show.res$+> %form!enctype=$enctype$+>     %table+>         ^form^+>         %tr+>             %td!colspan=2+>                 %input!type=submit+> |]+> +> main = basicHandler 3000 FormExample

@@ -0,0 +1,72 @@+{-# LANGUAGE TypeFamilies, QuasiQuotes, GeneralizedNewtypeDeriving #-}+{-# LANGUAGE FlexibleInstances #-}+{-# LANGUAGE MultiParamTypeClasses #-}+import Yesod+import Yesod.Helpers.Crud+import Yesod.Form.Jquery+import Yesod.Form.Nic+import Database.Persist.Sqlite+import Database.Persist.TH+import Data.Time (Day)++share2 mkToForm mkPersist [$persist|+Entry+    title String+    day Day Desc toFormField=YesodJquery.jqueryDayField+    content Html toFormField=YesodNic.nicHtmlField+    deriving+|]++instance Item Entry where+    itemTitle = entryTitle++data Blog = Blog { pool :: ConnectionPool }++type EntryCrud = Crud Blog Entry++mkYesod "Blog" [$parseRoutes|+/ RootR GET+/entry/#EntryId EntryR GET+/admin AdminR EntryCrud defaultCrud+|]++instance Yesod Blog where+    approot _ = "http://localhost:3000"++instance YesodPersist Blog where+    type YesodDB Blog = SqlPersist+    runDB db = fmap pool getYesod >>= runSqlPool db++instance YesodJquery Blog+instance YesodNic Blog++getRootR = do+    entries <- runDB $ selectList [] [EntryDayDesc] 0 0+    defaultLayout $ do+        setTitle $ string "Yesod Blog Tutorial Homepage"+        addBody [$hamlet|+%h1 Archive+%ul+    $forall entries entry+        %li+            %a!href=@EntryR.fst.entry@ $entryTitle.snd.entry$+%p+    %a!href=@AdminR.CrudListR@ Admin+|]++getEntryR entryid = do+    entry <- runDB $ get404 entryid+    defaultLayout $ do+        setTitle $ string $ entryTitle entry+        addBody [$hamlet|+%h1 $entryTitle.entry$+%h2 $show.entryDay.entry$+$entryContent.entry$+|]++withBlog f = withSqlitePool "blog.db3" 8 $ \pool -> do+    flip runSqlPool pool $ runMigration $ do+        migrate (undefined :: Entry)+    f $ Blog pool++main = withBlog $ basicHandler 3000