Add websocket event and cache invalidation for deleting channels (#2807)

api/channel.go

@@ -687,14 +687,20 @@ func deleteChannel(c *Context, w http.ResponseWriter, r *http.Request) {
 
 		c.LogAudit("name=" + channel.Name)
 
-		post := &model.Post{ChannelId: channel.Id, Message: fmt.Sprintf(
-			c.T("api.channel.delete_channel.archived"),
-			user.Username)}
-		if _, err := CreatePost(c, post, false); err != nil {
-			l4g.Error(utils.T("api.channel.delete_channel.failed_post.error"), err)
-			c.Err = model.NewLocAppError("deleteChannel", "api.channel.delete_channel.failed_send.app_error", nil, "")
-			return
-		}
+		go func() {
+			InvalidateCacheForChannel(channel.Id)
+			message := model.NewMessage(c.TeamId, channel.Id, c.Session.UserId, model.ACTION_CHANNEL_DELETED)
+			PublishAndForget(message)
+
+			post := &model.Post{
+				ChannelId: channel.Id,
+				Message:   fmt.Sprintf(c.T("api.channel.delete_channel.archived"), user.Username),
+				Type:      model.POST_CHANNEL_DELETED,
+			}
+			if _, err := CreatePost(c, post, false); err != nil {
+				l4g.Error(utils.T("api.channel.delete_channel.failed_post.error"), err)
+			}
+		}()
 
 		result := make(map[string]string)
 		result["id"] = channel.Id

api/web_conn.go

@@ -118,6 +118,10 @@ func (c *WebConn) InvalidateCache() {
 	c.hasPermissionsToTeam = make(map[string]bool)
 }
 
+func (c *WebConn) InvalidateCacheForChannel(channelId string) {
+	delete(c.hasPermissionsToChannel, channelId)
+}
+
 func (c *WebConn) HasPermissionsToTeam(teamId string) bool {
 	perm, ok := c.hasPermissionsToTeam[teamId]
 	if !ok {

api/web_hub.go

@@ -10,21 +10,23 @@ import (
 )
 
 type Hub struct {
-	connections    map[*WebConn]bool
-	register       chan *WebConn
-	unregister     chan *WebConn
-	broadcast      chan *model.Message
-	stop           chan string
-	invalidateUser chan string
+	connections       map[*WebConn]bool
+	register          chan *WebConn
+	unregister        chan *WebConn
+	broadcast         chan *model.Message
+	stop              chan string
+	invalidateUser    chan string
+	invalidateChannel chan string
 }
 
 var hub = &Hub{
-	register:       make(chan *WebConn),
-	unregister:     make(chan *WebConn),
-	connections:    make(map[*WebConn]bool),
-	broadcast:      make(chan *model.Message),
-	stop:           make(chan string),
-	invalidateUser: make(chan string),
+	register:          make(chan *WebConn),
+	unregister:        make(chan *WebConn),
+	connections:       make(map[*WebConn]bool),
+	broadcast:         make(chan *model.Message),
+	stop:              make(chan string),
+	invalidateUser:    make(chan string),
+	invalidateChannel: make(chan string),
 }
 
 func PublishAndForget(message *model.Message) {
@@ -37,6 +39,10 @@ func InvalidateCacheForUser(userId string) {
 	hub.invalidateUser <- userId
 }
 
+func InvalidateCacheForChannel(channelId string) {
+	hub.invalidateChannel <- channelId
+}
+
 func (h *Hub) Register(webConn *WebConn) {
 	h.register <- webConn
 }
@@ -74,6 +80,11 @@ func (h *Hub) Start() {
 					}
 				}
 
+			case channelId := <-h.invalidateChannel:
+				for webCon := range h.connections {
+					webCon.InvalidateCacheForChannel(channelId)
+				}
+
 			case msg := <-h.broadcast:
 				for webCon := range h.connections {
 					if shouldSendEvent(webCon, msg) {
@@ -136,8 +147,8 @@ func shouldSendEvent(webCon *WebConn, msg *model.Message) bool {
 			}
 		}
 
-		// Only report events to users who are in the channel for the event
-		if len(msg.ChannelId) > 0 {
+		// Only report events to users who are in the channel for the event execept deleted events
+		if len(msg.ChannelId) > 0 && msg.Action != model.ACTION_CHANNEL_DELETED {
 			allowed := webCon.HasPermissionsToChannel(msg.ChannelId)
 
 			if !allowed {