Worked out composition for refined editor proposal

Libraries/iTasks/UI/RefinedEditor.dcl

 definition module iTasks.UI.RefinedEditor
 
+//TODO: Use (p r w) instead of v for external interface
+//Tasks to handle side-effects just write commands to the share?
+
 //Collaboration with a distributed message set and versions needs to be built into
 //interact. The state and message queue will be shared between tasks instead of the editor value
 CollabModel s :== (Versioned s, [Versioned EditorUpdate])
@@ -7,7 +10,6 @@ Versioned a :== (!Int,!a)
 
 SDS Int (Either (Version s) [Version s])
 
-//Tasks to handle side-effects
 
 //Definition of an editor
 //Each editor defines a client and a server component with their own state.
@@ -15,32 +17,38 @@ SDS Int (Either (Version s) [Version s])
 
 :: [(String, c -> (c, Maybe msg))] -> EditorClient c msg
 
-:: Editor v s c = E. msg:
-	{ client :: EditorClient c msg
-	, server :: EditorServer v s c msg
+//v = Value the editor represents (print/parse to lower level)
+//s = Raw server state, for example an unparsed string
+//c = Client configuration, the initial setup of a client component
+//m = Message type, used for communicating between client and server
+
+:: Editor v s c m = 
+	{ client :: EditorClient c m
+	, server :: EditorServer v s c m
 	}
 
-:: EditorClient c msg =
-	{ init      :: c !JSObject *JSWorld -> *(!Maybe msg, !*JSWorld)
+:: EditorClient c m =
+	{ init      :: c !JSObject *JSWorld -> *(!Maybe m, !*JSWorld)
 	, destroy   :: !JSObject *JSWorld -> *JSWorld
 
-	, onEvent   :: !String !JSObject !JSObject !*JSWorld -> (!Maybe msg, !*JSWorld)
-	, onMessage :: msg !JSObject !*JSWorld -> *(!Maybe msg, !*JSWorld)
-
-	, setState  :: c !JSObject !*JSWorld -> *(!Maybe msg, *JSWorld)
-	, getState  :: !JSObject !*JSWorld -> *(!c, *JSWorld)
+	//Something happened in the javascript/DOM world
+	, onEvent   :: !String !JSObject !JSObject !*JSWorld -> (!Maybe m, !*JSWorld)
+	//A message from the server arrived
+	, onMessage :: m !JSObject !*JSWorld -> *(!Maybe m, !*JSWorld)
 	}
 
-:: EditorServer v s c msg = 
-	{ init      :: s -> c //Derive the initial client state from the server state
+:: EditorServer v s c m = 
+	{ configure :: s -> c //Derive the initial client configuration 
 
-	, onSet     :: s s -> (s, Maybe msg)
-	, onMessage :: msg s -> (s, Maybe msg)
+	, onRefresh :: s s -> (s, Maybe m)
+	, onMessage :: m s -> (s, Maybe m)
 
-	, toValue   :: s -> EditorValue v 
-	, fromValue :: (EditorValue v) -> s
+	, value     :: ((EditorValue v) -> s, s -> EditorValue v) //How to get to/from the validated domain
 	}
 
+//Exposing editors valid/invalid/empty judgement
+:: EditorValue a = ValidValue a | InvalidValue | EmptyValue
+
 class EditorMessage m
 where
 	encodeEditorMessage :: m -> EditStateUpdate
@@ -51,14 +59,12 @@ where
 	encodeEditorState :: s -> EditState
 	decodeEditorState :: EditState -> s
 
-//Exposing editors valid/invalid/empty judgement
-:: EditorValue a = ValidValue a | InvalidValue | EmptyValue
-
 //Generic untyped edit state
 :: EditState =
 	{ attributes :: Map AttributeName AttributeValue
 	, children   :: [EditState]
 	}
+
 :: AttributeName :== String
 :: AttributeValue :== JSONNode
 
@@ -73,7 +79,6 @@ where
 :: ClientState :== EditState
 :: ServerState :== EditState
 
-
 //Editor composition
 //- client side without communication
 //- service
@@ -84,14 +89,14 @@ where
 // - Dynamic label that shows the number of items
 // - Buttons with each item for moving i
 
-listEditor :: (Editor a s c) -> Editor [a] [s] [c]
+listEditor :: (Editor a s c m) -> Editor [a] [s] [c] (Int,m)
 
 label :: String -> Editor String () LabelDef
-button :: String -> Editor Bool Bool ButtonDef
-textView :: Editor String TextViewDef TextViewDef
-textField :: Editor String TextFieldDef TextFieldDef
+button :: (Bool -> ButtonDef) -> Editor Bool Bool ButtonDef Bool
+textView :: Editor String TextViewDef TextViewDef String 
+textField :: Editor String TextFieldDef TextFieldDef String
 
-integerField :: Editor Int TextFieldDef TextFieldDef
+integerField :: Editor Int TextFieldDef TextFieldDef String
 
 :: ButtonDef =
 	{ clicked   :: Bool
@@ -109,6 +114,50 @@ integerField :: Editor Int TextFieldDef TextFieldDef
 	{ text :: String
 	}
 
-//editor voor getal 
-//editor voor boolean (checkbox)
-//combinatie voor (maybe getal)
+//Editor for numbers
+//Editor for boolean (checkbox)
+//Combination: for maybe number
+
+//Compose by juxtaposition, no need to specify interdependency
+glue :: (Editor v1 s1 c1 m1)
+	(Editor v2 s2 c2 m2)
+	->
+	(Editor (EditorValue v1, EditorValue v2) (s1,s2) (c1,c2) (Maybe m1, Maybe m2))
+
+//Define the dependencies by defining feedback on messages
+link :: 
+	((c1,c2) -> (c1,c2)) //Rewrite the initial client configuration
+	((Maybe m1, Maybe m2) -> ((Maybe m1, Maybe m2),(Maybe m1, Maybe m2))) //Rewrite from server to client with feedback to server
+	((Maybe m1, Maybe m2) -> ((Maybe m1, Maybe m2),(Maybe m1, Maybe m2))) //Rewrite from client to server with feedback to client
+	(Editor v s (c1,c2) (Maybe m1, Maybe m2))
+	->	
+	(Editor v s (c1,c2) (Maybe m1, Maybe m2))
+
+//Get rid of the tuples and combine the parts into a unified state, configuration and 
+fuse :: 
+	((c1,c2) -> c, c -> (c1,c2))                                 //Unify client configuration
+	((s1,s2) -> s, s -> (s1,s2))                                 //Unify server state
+	(m -> (Maybe m1, Maybe m2), (Maybe m1, Maybe m2) -> Maybe m) //Unify messages
+	(EditorValue v -> (EditorValue v1, EditorValue v2), (EditorValue v1,EditorValue v2) -> EditorValue v) //Unity checked interface
+	(Editor (EditorValue v1, EditorValue v2) (s1,s2) (c1,c2) (Maybe m1, Maybe m2))
+	-> 
+	(Editor v s c m)
+
+//Example : Texfield with reset button
+resettableField = fuseFst buttonconfig (link id serverlink clientlink (glue textField (button (const buttonconfig))))
+where
+  clientlink (_,Just True) = ((Just "",Nothing), (Just "",Just False)) //When button is clicked, reset both local and remote
+  clientlink (mt,mb) = ((mt,mb),(Nothing,Nothing)
+
+  serverlink m = (m,(Nothing,Nothing)) //No feedback serverside
+
+  buttonconfig = {ButtonDef|clicked=False,label=Just "Reset",icon=Nothing}
+
+  //Common pattern: expose first component
+  fuseFst sndCfg editor = fuse clientconfig serverstate messages interface
+  where
+    clientconfig = (fst, \s -> (s,sndCfg))        //Reset button is statically configured
+    serverstate  = (fst, \s -> (s,False))         //Only server state of the textfield is stored
+    messages     = (\m -> (Just m,Nothing), fst)  //Drop messages for second part of the tuple
+    interface    = (x -> (x,EmptyValue), fst)     //Only consider first part as editor
+