[V3] Add docs for event.Sender (#4075)

* Add docs for event.Sender

* Update changelog

docs/src/content/docs/changelog.mdx

@@ -92,6 +92,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - In JS/TS bindings, named types are never rendered as aliases for other named types; the old behaviour is now restricted to aliases by [@fbbdev](https://github.com/fbbdev) in [#4045](https://github.com/wailsapp/wails/pull/4045)
 - In JS/TS bindings, in class mode, struct fields whose type is a type parameter are marked optional and never initialised automatically by [@fbbdev](https://github.com/fbbdev) in [#4045](https://github.com/wailsapp/wails/pull/4045)
 - Update copyright date to 2025 by [@IanVS](https://github.com/IanVS) in [#4037](https://github.com/wailsapp/wails/pull/4037)
+- Add docs for event.Sender by [@IanVS](https://github.com/IanVS) in [#4075](https://github.com/wailsapp/wails/pull/4075)
 
 ## v3.0.0-alpha.9 - 2025-01-13
 

docs/src/content/docs/learn/events.mdx

@@ -445,9 +445,10 @@ app.OnEvent("myevent", func(e *application.CustomEvent) {
     // Access event information
     name := e.Name        // Event name
     data := e.Data        // Event data
-    sender := e.Sender    // Event sender
+    sender := e.Sender    // Name of the window sending the event, or "" if sent from application
     cancelled := e.IsCancelled()  // Event cancellation status
 })
+```
 
 ## Event Cancellation
 

v3/pkg/application/events.go

@@ -52,7 +52,7 @@ var menuItemClicked = make(chan uint, 5)
 type CustomEvent struct {
 	Name      string `json:"name"`
 	Data      any    `json:"data"`
-	Sender    string `json:"sender"`
+	Sender    string `json:"sender"` // Name of the window sending the event, or "" if sent from application
 	cancelled bool
 	lock      sync.RWMutex
 }