URLs are modifiable via IORefs

Yesod/Form.hs

@@ -101,6 +101,7 @@ import Yesod.Widget
 import Control.Arrow ((&&&))
 import qualified Text.Email.Validate as Email
 import Data.Char (isSpace)
+import Yesod.Urls
 
 -- | A form can produce three different results: there was no data available,
 -- the data was invalid, or there was a successful parse.
@@ -427,9 +428,9 @@ jqueryDayFieldProfile = FieldProfile
 %input#$name$!name=$name$!type=date!:isReq:required!value=$val$
 |]
     , fpWidget = \name -> do
-        addScriptRemote urlJqueryJs
-        addScriptRemote urlJqueryUiJs
-        addStylesheetRemote urlJqueryUiCss
+        getSetting urlJqueryJs >>= addScriptRemote
+        getSetting urlJqueryUiJs >>= addScriptRemote
+        getSetting urlJqueryUiCss >>= addStylesheetRemote
         addJavaScript [$hamlet|
 $$(function(){$$("#$name$").datepicker({dateFormat:'yy-mm-dd'})});
 |]
@@ -460,10 +461,6 @@ parseUTCTime s =
             Right date -> ifRight (parseTime timeS)
                                   (\time -> UTCTime date (timeOfDayToTime time))
 
--- TODO - integrate with static helpers
-jqueryUiDateTimePicker :: String
-jqueryUiDateTimePicker = "http://www.projectcodegen.com/jquery.ui.datetimepicker.js.txt"
-
 jqueryDayTimeField :: Html () -> Html () -> FormletField sub y UTCTime
 jqueryDayTimeField l t = requiredFieldHelper jqueryDayTimeFieldProfile
     { fpLabel = l , fpTooltip = t }
@@ -485,23 +482,23 @@ jqueryDayTimeUTCTime (UTCTime day utcTime) =
 
 jqueryDayTimeFieldProfile :: FieldProfile sub y UTCTime
 jqueryDayTimeFieldProfile = FieldProfile
-    { fpParse  = parseUTCTime 
+    { fpParse  = parseUTCTime
     , fpRender = jqueryDayTimeUTCTime
     , fpHamlet = \name val isReq -> [$hamlet|
 %input#$name$!name=$name$!type=date!:isReq:required!value=$val$
 |]
     , fpWidget = \name -> do
-        addScriptRemote urlJqueryJs
-        addScriptRemote urlJqueryUiJs
-        addScriptRemote jqueryUiDateTimePicker -- needs slashes, dashes are broken
-        addStylesheetRemote urlJqueryUiCss
+        getSetting urlJqueryJs >>= addScriptRemote
+        getSetting urlJqueryUiJs >>= addScriptRemote
+        getSetting urlJqueryUiDateTimePicker >>= addScriptRemote -- needs slashes, dashes are broken
+        getSetting urlJqueryUiCss >>= addStylesheetRemote
         addJavaScript [$hamlet|
 $$(function(){$$("#$name$").datetimepicker({dateFormat : "yyyy/mm/dd h:MM TT"})});
 |]
     , fpName = Nothing
     , fpLabel = mempty
     , fpTooltip = mempty
-    } 
+    }
 
 parseTime :: String -> Either String TimeOfDay
 parseTime (h2:':':m1:m2:[]) = parseTimeHelper ('0', h2, m1, m2, '0', '0')
@@ -893,9 +890,9 @@ jqueryAutocompleteFieldProfile src = FieldProfile
 %input.autocomplete#$name$!name=$name$!type=text!:isReq:required!value=$val$
 |]
     , fpWidget = \name -> do
-        addScriptRemote urlJqueryJs
-        addScriptRemote urlJqueryUiJs
-        addStylesheetRemote urlJqueryUiCss
+        getSetting urlJqueryJs >>= addScriptRemote
+        getSetting urlJqueryUiJs >>= addScriptRemote
+        getSetting urlJqueryUiCss >>= addStylesheetRemote
         addJavaScript [$hamlet|
 $$(function(){$$("#$name$").autocomplete({source:"@src@",minLength:2})});
 |]

Yesod/Urls.hs

@@ -0,0 +1,43 @@
+module Yesod.Urls
+    ( newSetting
+    , changeSetting
+    , getSetting
+      -- * Default library URLs
+    , urlJqueryJs
+    , urlJqueryUiJs
+    , urlJqueryUiCss
+    , urlJqueryUiDateTimePicker
+    ) where
+
+import Data.IORef (IORef, newIORef, writeIORef, readIORef)
+import System.IO.Unsafe (unsafePerformIO)
+import Control.Monad.IO.Class
+
+newSetting :: a -> IORef a
+newSetting = unsafePerformIO . newIORef
+
+changeSetting :: MonadIO m => IORef a -> a -> m ()
+changeSetting x = liftIO . writeIORef x
+
+getSetting :: MonadIO m => IORef a -> m a
+getSetting = liftIO . readIORef
+
+-- | The Google-hosted jQuery 1.4.2 file.
+urlJqueryJs :: IORef String
+urlJqueryJs = newSetting
+    "http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"
+
+-- | The Google-hosted jQuery UI 1.8.1 javascript file.
+urlJqueryUiJs :: IORef String
+urlJqueryUiJs = newSetting
+    "http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.1/jquery-ui.min.js"
+
+-- | The Google-hosted jQuery UI 1.8.1 CSS file with cupertino theme.
+urlJqueryUiCss :: IORef String
+urlJqueryUiCss = newSetting
+    "http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.1/themes/cupertino/jquery-ui.css"
+
+-- TODO - integrate with static helpers
+urlJqueryUiDateTimePicker :: IORef String
+urlJqueryUiDateTimePicker = newSetting
+    "http://www.projectcodegen.com/jquery.ui.datetimepicker.js.txt"

Yesod/Widget.hs

@@ -27,10 +27,6 @@ module Yesod.Widget
       -- * Manipulating
     , wrapWidget
     , extractBody
-      -- * Default library URLs
-    , urlJqueryJs
-    , urlJqueryUiJs
-    , urlJqueryUiCss
     ) where
 
 import Data.List (nub)
@@ -204,18 +200,3 @@ extractBody (GWidget w) =
     GWidget $ mapWriterT (fmap go) w
   where
     go ((), Body h) = (h, Body mempty)
-
--- | The Google-hosted jQuery 1.4.2 file.
-urlJqueryJs :: String
-urlJqueryJs =
-    "http://ajax.googleapis.com/ajax/libs/jquery/1.4.2/jquery.min.js"
-
--- | The Google-hosted jQuery UI 1.8.1 javascript file.
-urlJqueryUiJs :: String
-urlJqueryUiJs =
-    "http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.1/jquery-ui.min.js"
-
--- | The Google-hosted jQuery UI 1.8.1 CSS file with cupertino theme.
-urlJqueryUiCss :: String
-urlJqueryUiCss =
-    "http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.1/themes/cupertino/jquery-ui.css"

yesod.cabal

@@ -53,6 +53,7 @@ library
                      Yesod.Handler
                      Yesod.Internal
                      Yesod.Json
+                     Yesod.Urls
                      Yesod.Request
                      Yesod.Widget
                      Yesod.Yesod