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Main only starts App.Container.

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Philippe Pittoli 2023-05-22 20:02:53 +02:00
parent b4f5a4aefa
commit 29ee6f9a87
1 changed files with 3 additions and 400 deletions
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src/Main.purs
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module Main where
import Prelude
import Control.Monad.Except (runExcept)
import Control.Monad.State (class MonadState)
import Data.Array as A
import Data.Bifunctor (lmap)
-- import Data.Codec.Argonaut (JsonCodec, JsonDecodeError)
-- import Data.Codec.Argonaut as CA
import Data.Const (Const)
import Data.Either (Either(..))
import Data.Maybe (Maybe(..), isJust, isNothing, maybe)
import Data.String as String
import Effect (Effect)
import Effect.Aff.Class (class MonadAff)
import Foreign (Foreign)
import Foreign as F
import Halogen as H
import Halogen.Aff (awaitBody, runHalogenAff) as HA
import Halogen.HTML as HH
import Halogen.HTML.Events as HE
import Halogen.HTML.Properties as HP
import Halogen.Query.Event as HQE
import Halogen.Subscription as HS
import Halogen.Aff as HA
import Halogen.VDom.Driver (runUI)
import Web.Event.Event (Event)
import Web.Event.Event as Event
import Web.Socket.Event.CloseEvent as WSCE
import Web.Socket.Event.EventTypes as WSET
import Web.Socket.Event.MessageEvent as WSME
import Web.Socket.ReadyState (ReadyState(Connecting, Open, Closing, Closed))
import Web.Socket.WebSocket as WS
import Data.ArrayBuffer.Types (ArrayBuffer)
import Web.Socket.BinaryType (BinaryType(ArrayBuffer))
import App.IPC (toIPC, fromIPC)
--------------------------------------------------------------------------------
-- WebSocketEvent type
--------------------------------------------------------------------------------
data WebSocketEvent :: Type -> Type
data WebSocketEvent msg
= WebSocketMessage { message :: msg, origin :: String, lastEventId :: String }
| WebSocketOpen
| WebSocketClose { code :: Int, reason :: String, wasClean :: Boolean }
| WebSocketError ErrorType
webSocketEmitter :: WS.WebSocket -> HS.Emitter (WebSocketEvent WebSocketMessageType)
webSocketEmitter socket = do
HS.makeEmitter \push -> do
openId <- HS.subscribe openEmitter push
errorId <- HS.subscribe errorEmitter push
closeId <- HS.subscribe closeEmitter push
messageId <- HS.subscribe messageEmitter push
pure do
HS.unsubscribe openId
HS.unsubscribe errorId
HS.unsubscribe closeId
HS.unsubscribe messageId
where
target = WS.toEventTarget socket
openEmitter :: HS.Emitter (WebSocketEvent WebSocketMessageType)
openEmitter =
HQE.eventListener WSET.onOpen target \_ ->
Just WebSocketOpen
errorEmitter :: HS.Emitter (WebSocketEvent WebSocketMessageType)
errorEmitter =
HQE.eventListener WSET.onError target \_ ->
Just (WebSocketError UnknownWebSocketError)
closeEmitter :: HS.Emitter (WebSocketEvent WebSocketMessageType)
closeEmitter =
HQE.eventListener WSET.onClose target \event ->
WSCE.fromEvent event >>= \closeEvent ->
Just $ WebSocketClose { code: WSCE.code closeEvent
, reason: WSCE.reason closeEvent
, wasClean: WSCE.wasClean closeEvent
}
messageEmitter :: HS.Emitter (WebSocketEvent WebSocketMessageType)
messageEmitter = HQE.eventListener WSET.onMessage target (WSME.fromEvent >=> decodeMessageEvent)
decodeMessageEvent :: WSME.MessageEvent -> Maybe (WebSocketEvent WebSocketMessageType)
decodeMessageEvent = \msgEvent -> do
let
foreign' :: Foreign
foreign' = WSME.data_ msgEvent
case foreignToArrayBuffer foreign' of
Left errs -> pure $ WebSocketError $ UnknownError errs
Right arrayBuffer -> pure $ WebSocketMessage { message: arrayBuffer, origin: WSME.origin msgEvent, lastEventId: WSME.lastEventId msgEvent }
---------------------------
-- Errors
---------------------------
data ErrorType
= MessageIsServerAdvertisement String
| UnknownError String
| UnknownWebSocketError
renderError :: ErrorType -> String
renderError = case _ of
UnknownError str ->
"Unknown error: " <> str
MessageIsServerAdvertisement str ->
"Received following advertisment from server: " <> str
UnknownWebSocketError ->
"Unknown 'error' event has been fired by WebSocket event listener"
--------------------------------------------------------------------------------
-- `Main` function
--------------------------------------------------------------------------------
import App.Container as Container
main :: Effect Unit
main = HA.runHalogenAff do
body <- HA.awaitBody
let url = "ws://localhost:8080"
runUI rootComponent url body
-- runUI Container.component unit body
--------------------------------------------------------------------------------
-- WebSocket message type
--------------------------------------------------------------------------------
type WebSocketMessageType = ArrayBuffer
--------------------------------------------------------------------------------
-- Root component module
--------------------------------------------------------------------------------
type Query :: forall k. k -> Type
type Query = Const Void
type Input = String
type Output = Void
data Action
= Initialize
| WebSocketParseError String
| ConnectWebSocket
| HandleInputUpdate String
| SendMessage Event
| HandleWebSocket (WebSocketEvent WebSocketMessageType)
type State =
{ messages :: Array String
, messageHistoryLength :: Int
, inputText :: String
, wsUrl :: String
, wsConnection :: Maybe WS.WebSocket
, canReconnect :: Boolean
}
rootComponent :: forall m. MonadAff m => H.Component Query Input Output m
rootComponent =
H.mkComponent
{ initialState
, render
, eval: H.mkEval $ H.defaultEval
{ initialize = Just Initialize
, handleAction = handleAction
}
}
initialState :: Input -> State
initialState input =
{ messages: []
, messageHistoryLength: 10
, inputText: ""
, wsUrl: input
, wsConnection: Nothing
, canReconnect: false
}
wrapperStyle :: String
wrapperStyle =
"""
display: block;
flex-direction: column;
justify-content: space-between;
height: calc(100vh - 30px);
background: #282c34;
color: #e06c75;
font-family: 'Consolas';
padding: 5px 20px 5px 20px;
"""
render :: forall m. State -> H.ComponentHTML Action () m
render { messages, inputText, wsConnection, canReconnect, messageHistoryLength } =
HH.div
[ HP.style wrapperStyle ]
[ HH.h2_ [ HH.text "WebSocket example for PureScript Halogen" ]
, HH.form
[ HE.onSubmit SendMessage ]
[ HH.ul_ $ map (\msg -> HH.li_ [ HH.text msg ]) messages
, HH.p_
[ HH.div_
[ HH.input
[ HP.style "padding: 0.5rem 0.75rem; margin-bottom: 0.25rem;"
, HP.type_ HP.InputText
, HP.value inputText
, HE.onValueInput HandleInputUpdate
, maybe (HP.disabled true) (\_ -> HP.enabled true) wsConnection
]
]
, HH.div_
[ HH.button
[ HP.style "padding: 0.5rem 1.25rem;"
, HP.type_ HP.ButtonSubmit
, maybe (HP.disabled true) (\_ -> HP.enabled true) wsConnection
]
[ HH.text "Send Message to Server" ]
]
]
, renderMaxHistoryLength messageHistoryLength
, renderReconnectButton (isNothing wsConnection && canReconnect)
]
]
where
renderFootnote :: String -> H.ComponentHTML Action () m
renderFootnote txt =
HH.div [ HP.style "margin-bottom: 0.125rem; color: grey;" ] [ HH.small_ [ HH.text txt ] ]
renderMaxHistoryLength :: Int -> H.ComponentHTML Action () m
renderMaxHistoryLength len =
renderFootnote ("NOTE: Maximum chat history length is " <> show len <> " messages")
renderReconnectButton :: Boolean -> H.ComponentHTML Action () m
renderReconnectButton cond =
if cond
then
HH.p_
[ HH.button
[ HP.type_ HP.ButtonButton
, HE.onClick \_ -> ConnectWebSocket
]
[ HH.text "Reconnect?" ]
]
else
HH.p_
[ renderFootnote "NOTE: A 'Reconnect?' button will appear if the connection drops"
, renderFootnote "NOTE: You can type /disconnect to manually disconnect"
]
handleAction :: forall m. MonadAff m => Action -> H.HalogenM State Action () Output m Unit
handleAction = case _ of
Initialize ->
handleAction ConnectWebSocket
WebSocketParseError error ->
systemMessage $ renderError (UnknownError error)
ConnectWebSocket -> do
{ wsUrl } <- H.get
systemMessage ("Connecting to \"" <> wsUrl <> "\"...")
webSocket <- H.liftEffect $ WS.create wsUrl []
H.liftEffect $ WS.setBinaryType webSocket ArrayBuffer
H.modify_ _ { wsConnection = Just webSocket }
void $ H.subscribe (HandleWebSocket <$> webSocketEmitter webSocket)
HandleInputUpdate text -> do
H.modify_ _ { inputText = text }
SendMessage ev -> do
H.liftEffect $ Event.preventDefault ev
{ wsConnection, inputText } <- H.get
case wsConnection, inputText of
Nothing, _ ->
unableToSend "Not connected to server."
Just _ , "" ->
unableToSend "Cannot send an empty message"
Just webSocket, outgoingMessage -> do
H.liftEffect (WS.readyState webSocket) >>= case _ of
Connecting ->
unableToSend "Still connecting to server."
Closing ->
unableToSend "Connection to server is closing."
Closed -> do
unableToSend "Connection to server has been closed."
maybeCurrentConnection <- H.gets _.wsConnection
when (isJust maybeCurrentConnection) do
H.modify_ _ { wsConnection = Nothing, canReconnect = true }
Open -> do
case outgoingMessage of
"/disconnect" -> do
H.liftEffect $ WS.close webSocket
systemMessageReset $ "You have requested to disconnect from the server"
otherMessage -> do
H.liftEffect $ do
ab <- toIPC otherMessage
sendArrayBuffer webSocket ab
appendMessageReset $ "[😇] You: " <> otherMessage
HandleWebSocket wsEvent ->
case wsEvent of
WebSocketMessage messageEvent -> do
receivedMessage <- H.liftEffect $ fromIPC messageEvent.message
case receivedMessage of
Left parseError -> do
handleAction $ WebSocketParseError $ show parseError
Right string -> do
appendMessage $ "[😈] Server: " <> string
WebSocketOpen -> do
{ wsUrl } <- H.get
systemMessage ("Successfully connected to WebSocket at \"" <> wsUrl <> "\"!🎉")
WebSocketClose { code, reason, wasClean } -> do
systemMessage $ renderCloseMessage code wasClean reason
maybeCurrentConnection <- H.gets _.wsConnection
when (isJust maybeCurrentConnection) do
H.modify_ _ { wsConnection = Nothing, canReconnect = true }
WebSocketError errorType ->
systemMessage $ renderError errorType
where
renderCloseMessage
:: Int
-> Boolean
-> String
-> String
renderCloseMessage code wasClean = case _ of
"" -> baseCloseMessage
reason -> baseCloseMessage <> "Reason: " <> reason
where
baseCloseMessage :: String
baseCloseMessage =
String.joinWith " "
[ "Connection to WebSocket closed"
, "[ CODE:"
, show code
, "|"
, if wasClean then "CLEAN" else "DIRTY"
, "]"
]
sendArrayBuffer :: WS.WebSocket -> ArrayBuffer -> Effect Unit
sendArrayBuffer = WS.sendArrayBuffer
--------------------------------------------------------------------------------
-- Helpers for updating the array of messages sent/received
--------------------------------------------------------------------------------
-- Append a new message to the chat history, with a boolean that allows you to
-- clear the text input field or not. The number of displayed `messages` in the
-- chat history (including system) is controlled by the `messageHistoryLength`
-- field in the component `State`.
appendMessageGeneric :: forall m. MonadState State m => Boolean -> String -> m Unit
appendMessageGeneric clearField msg = do
histSize <- H.gets _.messageHistoryLength
if clearField
then H.modify_ \st ->
st { messages = appendSingle histSize msg st.messages, inputText = "" }
else H.modify_ \st ->
st { messages = appendSingle histSize msg st.messages }
where
-- Limits the nnumber of recent messages to `maxHist`
appendSingle :: Int -> String -> Array String -> Array String
appendSingle maxHist x xs
| A.length xs < maxHist = xs `A.snoc` x
| otherwise = (A.takeEnd (maxHist-1) xs) `A.snoc` x
-- Append a new message to the chat history, while not clearing
-- the user input field
appendMessage :: forall m. MonadState State m => String -> m Unit
appendMessage = appendMessageGeneric false
-- Append a new message to the chat history and also clear
-- the user input field
appendMessageReset :: forall m. MonadState State m => String -> m Unit
appendMessageReset = appendMessageGeneric true
-- Append a system message to the chat log.
systemMessage :: forall m. MonadState State m => String -> m Unit
systemMessage msg = appendMessage ("[🤖] System: " <> msg)
-- As above, but also clears the user input field. e.g. in
-- the case of a "/disconnect" command
systemMessageReset :: forall m. MonadState State m => String -> m Unit
systemMessageReset msg = appendMessageReset ("[🤖] System: " <> msg)
-- A system message to use when a message cannot be sent.
unableToSend :: forall m. MonadState State m => String -> m Unit
unableToSend reason = systemMessage ("Unable to send. " <> reason)
foreignToArrayBuffer :: Foreign -> Either String ArrayBuffer
foreignToArrayBuffer
= lmap renderForeignErrors
<<< runExcept
<<< F.unsafeReadTagged "ArrayBuffer"
where
renderForeignErrors :: F.MultipleErrors -> String
renderForeignErrors =
String.joinWith "; " <<< A.fromFoldable <<< map F.renderForeignError
runUI Container.component unit body