snapshot of https://github.com/mattermost/mattermost.git (master, 2026-09-16; blobs > 131072B omitted)

server/channels/app/platform/web_broadcast_hook.go

@@ -0,0 +1,90 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package platform
+
+import (
+	"github.com/mattermost/mattermost/server/public/model"
+	"github.com/mattermost/mattermost/server/public/shared/mlog"
+)
+
+type BroadcastHook interface {
+	// Process takes a WebSocket event and modifies it in some way. It is passed a HookedWebSocketEvent which allows
+	// safe modification of the event.
+	Process(msg *HookedWebSocketEvent, webConn *WebConn, args map[string]any) error
+}
+
+func (h *Hub) runBroadcastHooks(msg *model.WebSocketEvent, webConn *WebConn, hookIDs []string, hookArgs []map[string]any) *model.WebSocketEvent {
+	if len(hookIDs) == 0 {
+		return msg
+	}
+
+	hookedEvent := MakeHookedWebSocketEvent(msg)
+
+	for i, hookID := range hookIDs {
+		hook := h.broadcastHooks[hookID]
+		args := hookArgs[i]
+		if hook == nil {
+			mlog.Warn("runBroadcastHooks: Unable to find broadcast hook", mlog.String("hook_id", hookID))
+			continue
+		}
+
+		err := hook.Process(hookedEvent, webConn, args)
+		if err != nil {
+			mlog.Warn("runBroadcastHooks: Error processing hook", mlog.String("hook_id", hookID), mlog.Err(err))
+		}
+	}
+
+	return hookedEvent.Event()
+}
+
+// HookedWebSocketEvent is a wrapper for model.WebSocketEvent that is intended to provide a similar interface, except
+// it ensures the original WebSocket event is not modified.
+type HookedWebSocketEvent struct {
+	original *model.WebSocketEvent
+	copy     *model.WebSocketEvent
+}
+
+func MakeHookedWebSocketEvent(event *model.WebSocketEvent) *HookedWebSocketEvent {
+	return &HookedWebSocketEvent{
+		original: event,
+	}
+}
+
+func (he *HookedWebSocketEvent) Add(key string, value any) {
+	he.copyIfNecessary()
+
+	he.copy.Add(key, value)
+}
+
+func (he *HookedWebSocketEvent) EventType() model.WebsocketEventType {
+	if he.copy == nil {
+		return he.original.EventType()
+	}
+
+	return he.copy.EventType()
+}
+
+// Get returns a value from the WebSocket event data. You should never mutate a value returned by this method.
+func (he *HookedWebSocketEvent) Get(key string) any {
+	if he.copy == nil {
+		return he.original.GetData()[key]
+	}
+
+	return he.copy.GetData()[key]
+}
+
+// copyIfNecessary should be called by any mutative method to ensure that the copy is instantiated.
+func (he *HookedWebSocketEvent) copyIfNecessary() {
+	if he.copy == nil {
+		he.copy = he.original.RemovePrecomputedJSON()
+	}
+}
+
+func (he *HookedWebSocketEvent) Event() *model.WebSocketEvent {
+	if he.copy == nil {
+		return he.original
+	}
+
+	return he.copy
+}