Chatroom 2 (#10)

* Remove unused method. Don't panic if unknown room.

* Need a Connected() check for rooms publishing - don't do the work of rendering for a dead connection

* Make vars private.

* Linter issues

* Remove Connected()

* Mutation observer. Publish 4x / second.

---------

Co-authored-by: João Gonçalves <joao.goncalves01@gmail.com>

actiontrigger.go

@@ -83,7 +83,7 @@ func (a *actionTrigger) OnChange(options ...ActionTriggerOption) h.H {
 	return h.Data("on:change__debounce.200ms", buildOnExpr(actionURL(a.id), &opts))
 }
 
-// OneyDown returns a via.h DOM attribute that triggers when a key is pressed.
+// OnKeyDown returns a via.h DOM attribute that triggers when a key is pressed.
 // key: optional, see https://developer.mozilla.org/en-US/docs/Web/API/KeyboardEvent/key
 // Example: OnKeyDown("Enter")
 func (a *actionTrigger) OnKeyDown(key string, options ...ActionTriggerOption) h.H {

configuration.go

@@ -13,7 +13,7 @@ const (
 // Plugin is a func that can mutate the given *via.V app runtime. It is useful to integrate popular JS/CSS UI libraries or tools.
 type Plugin func(v *V)
 
-// Config defines configuration options for the via application.
+// Options defines configuration options for the via application
 type Options struct {
 	// The development mode flag. If true, enables server and browser auto-reload on `.go` file changes.
 	DevMode bool

context.go

@@ -182,9 +182,7 @@ func (c *Context) injectSignals(sigs map[string]any) {
 	}
 }
 
-// Sync pushes the current view state and signal changes to the browser immediately
+func (c *Context) getSSE() *datastar.ServerSentEventGenerator {
-// over the live SSE event stream.
-func (c *Context) Sync() {
 	// components use parent page sse stream
 	var sse *datastar.ServerSentEventGenerator
 	if c.isComponent() {
@@ -192,6 +190,13 @@ func (c *Context) Sync() {
 	} else {
 		sse = c.sse
 	}
+	return sse
+}
+
+// Sync pushes the current view state and signal changes to the browser immediately
+// over the live SSE event stream.
+func (c *Context) Sync() {
+	sse := c.getSSE()
 	if sse == nil {
 		c.app.logWarn(c, "view out of sync: no sse stream")
 		return
@@ -234,12 +239,7 @@ func (c *Context) Sync() {
 // Then, the merge will only occur if the ID of the top level element in the patch
 // matches 'my-element'.
 func (c *Context) SyncElements(elem h.H) {
-	var sse *datastar.ServerSentEventGenerator
+	sse := c.getSSE()
-	if c.isComponent() {
-		sse = c.parentPageCtx.sse
-	} else {
-		sse = c.sse
-	}
 	if sse == nil {
 		c.app.logWarn(c, "elements out of sync: no sse stream")
 		return
@@ -260,12 +260,7 @@ func (c *Context) SyncElements(elem h.H) {
 // SyncSignals pushes the current signal changes to the browser immediately
 // over the live SSE event stream.
 func (c *Context) SyncSignals() {
-	var sse *datastar.ServerSentEventGenerator
+	sse := c.getSSE()
-	if c.isComponent() {
-		sse = c.parentPageCtx.sse
-	} else {
-		sse = c.sse
-	}
 	if sse == nil {
 		c.app.logWarn(c, "signals out of sync: no sse stream")
 		return
@@ -285,12 +280,7 @@ func (c *Context) SyncSignals() {
 }
 
 func (c *Context) ExecScript(s string) {
-	var sse *datastar.ServerSentEventGenerator
+	sse := c.getSSE()
-	if c.isComponent() {
-		sse = c.parentPageCtx.sse
-	} else {
-		sse = c.sse
-	}
 	if sse == nil {
 		c.app.logWarn(c, "script out of sync: no sse stream")
 		return

h/h.go

@@ -31,7 +31,7 @@ func Textf(format string, a ...any) H {
 	return g.Textf(format, a...)
 }
 
-// / Raw creates a text DOM [Node] that just Renders the unescaped string t.
+// Raw creates a text DOM [Node] that just Renders the unescaped string t.
 func Raw(s string) H {
 	return g.Raw(s)
 }

internal/examples/chatroom/main.go

@@ -80,9 +80,8 @@ func main() {
 			`)), h.Script(h.Raw(`
 				function scrollChatToBottom() {
 					const chatHistory = document.querySelector('.chat-history');
-					if (chatHistory) chatHistory.scrollTop = chatHistory.scrollHeight;
+					chatHistory.scrollTop = chatHistory.scrollHeight;
 				}
-				setInterval(scrollChatToBottom, 100);
 			`)),
 	)
 	rooms := NewRooms[Chat, UserInfo]("Clojure", "Dotnet", "Go", "Java", "JS", "Kotlin", "Python", "Rust")
@@ -100,7 +99,10 @@ func main() {
 		var currentRoom *Room[Chat, UserInfo]
 
 		switchRoom := func() {
-			newRoom, _ := rooms.Get(string(roomName.String()))
+			newRoom, ok := rooms.Get(string(roomName.String()))
+			if !ok {
+				return
+			}
 			fmt.Println(">> switchRoom to ", newRoom.Name)
 			if currentRoom != nil && currentRoom != newRoom {
 				fmt.Println("LEAVING old room")
@@ -129,8 +131,8 @@ func main() {
 			if currentRoom != nil {
 				currentRoom.UpdateData(func(chat *Chat) {
 					chat.Entries = append(chat.Entries, ChatEntry{
-						User:    currentUser,
+						user:    currentUser,
-						Message: msg,
+						message: msg,
 					})
 				})
 				statement.SetValue("")
@@ -178,10 +180,10 @@ func main() {
 				})
 				for _, entry := range chat.Entries {
 
-					messageChildren := []h.H{h.Class("chat-message"), entry.User.Avatar()}
+					messageChildren := []h.H{h.Class("chat-message"), entry.user.Avatar()}
 					messageChildren = append(messageChildren,
 						h.Div(h.Class("bubble"),
-							h.P(h.Text(entry.Message)),
+							h.P(h.Text(entry.message)),
 						),
 					)
 
@@ -189,7 +191,10 @@ func main() {
 				}
 			}
 
-			chatHistory := []h.H{h.Class("chat-history")}
+			chatHistory := []h.H{
+				h.Class("chat-history"),
+				h.Script(h.Raw(`new MutationObserver((mutations)=>{scrollChatToBottom()}).observe(document.querySelector('.chat-history'), {childList:true})`)),
+			}
 			chatHistory = append(chatHistory, messages...)
 
 			return h.Main(h.Class("container"),
@@ -205,7 +210,7 @@ func main() {
 						h.Attr("role", "group"),
 						h.Input(
 							h.Type("text"),
-							h.Placeholder(fmt.Sprintf("%s says...", currentUser.Name)),
+							h.Placeholder(currentUser.Name+" says..."),
 							statement.Bind(),
 							h.Attr("autofocus"),
 							say.OnKeyDown("Enter"),
@@ -234,8 +239,8 @@ func (u *UserInfo) Avatar() h.H {
 }
 
 type ChatEntry struct {
-	User    UserInfo
+	user    UserInfo
-	Message string
+	message string
 }
 
 type Chat struct {

internal/examples/chatroom/rooms.go

@@ -94,7 +94,7 @@ func (r *Room[TR, TU]) Publish() {
 	}
 }
 
-// Get room data. This is a copy.
+// GetData returns a copy of room data.
 // Accepts an optional subset function to transform data before copying.
 func (r *Room[TR, TU]) GetData(subsetFn ...func(*TR) TR) TR {
 	r.dataMu.RLock()
@@ -116,12 +116,6 @@ func (r *Room[TR, TU]) Leave(u *TU) {
 	r.leave <- u
 }
 
-func (r *Room[TR, TU]) MemberCount() int {
-	r.membersMu.RLock()
-	defer r.membersMu.RUnlock()
-	return len(r.members)
-}
-
 func NewRoom[TR any, TU comparable](n string) *Room[TR, TU] {
 	return &Room[TR, TU]{
 		Name:        n,
@@ -135,7 +129,7 @@ func NewRoom[TR any, TU comparable](n string) *Room[TR, TU] {
 
 func (r *Room[TR, TU]) run() {
 	defer close(r.done)
-	publishTicker := time.NewTicker(400 * time.Millisecond)
+	publishTicker := time.NewTicker(250 * time.Millisecond)
 	defer publishTicker.Stop()
 	for {
 		select {

internal/examples/chatroom/rooms_test.go

@@ -56,7 +56,6 @@ func (ds *DummySyncable) Sync() {
 	ds.room.GetData()
 	ds.timesCalled++
 }
-
 func TestRoomJoinLeaveChannels(t *testing.T) {
 	rooms := NewRooms[RoomData, TestUserInfo](string("a"))
 	rm, _ := rooms.Get("a")
@@ -75,7 +74,7 @@ func TestRoomJoinLeaveChannels(t *testing.T) {
 	time.Sleep(1 * time.Millisecond)
 
 	assert.Equal(t, rm.dirty, false)
-	assert.Equal(t, rm.MemberCount(), 1)
+	assert.Equal(t, len(rm.members), 1)
 
 	// Room Data
 	rm.UpdateData(func(data *RoomData) {
@@ -96,5 +95,5 @@ func TestRoomJoinLeaveChannels(t *testing.T) {
 	rm.Leave(&u1)
 	time.Sleep(1 * time.Millisecond)
 
-	assert.Equal(t, rm.MemberCount(), 0)
+	assert.Equal(t, len(rm.members), 0)
 }