Add a websocket string binding

README.md

@@ -113,7 +113,28 @@ h := widget.NewHexWidget()
 h.Set(0xf)
 ```
 
-## Validation
+## Data Binding
+
+Community contributed data sources for binding.
+
+`import fyne.io/x/fyne/data/binding`
+
+### WebString
+
+A `WebSocketString` binding creates a `String` data binding to the specified web socket URL.
+Each time a message is read the value will be converted to a `string` and set on the binding.
+It is also `Closable` so you should be sure to call `Close()` once you are completed using it.
+
+```go
+s, err := binding.NewWebSocketString("wss://demo.piesocket.com/v3/channel_1?api_key=oCdCMcMPQpbvNjUIzqtvF1d2X2okWpDQj4AwARJuAgtjhzKxVEjQU6IdCjwm&notify_self")
+l := widget.NewLabelWithData(s)
+```
+
+The code above uses a test web sockets server from "PieSocket", you can run the code above
+and go to [their test page](https://www.piesocket.com/websocket-tester) to send messages.
+The widget will automatically update to the latest data sent through the socket.
+
+## Data Validation
 
 Community contributed validators.
 

data/binding/webstring.go

@@ -0,0 +1,61 @@
+// Package binding provides extended sources of data binding.
+package binding
+
+import (
+	"io"
+	"log"
+	"net/http"
+
+	"fyne.io/fyne/v2"
+	"fyne.io/fyne/v2/data/binding"
+
+	"github.com/gorilla/websocket"
+)
+
+// StringCloser is an extension of the String interface that allows resources to be freed
+// using the standard `Close()` method.
+type StringCloser interface {
+	binding.String
+	io.Closer
+}
+
+type webSocketString struct {
+	binding.String
+	conn *websocket.Conn
+}
+
+// NewWebSocketString returns a `String` binding to a web socket server specified as `url`.
+// The resulting string will be set to the content of the latest message sent through the socket.
+// You should also call `Close()` on the binding once you are done to free the connection.
+func NewWebSocketString(url string) (StringCloser, error) {
+	s := binding.NewString()
+	conn, _, err := websocket.DefaultDialer.Dial(url, http.Header{})
+	if err != nil {
+		return nil, err
+	}
+
+	go func() {
+		for {
+			_, p, err := conn.ReadMessage()
+			if err != nil {
+				log.Println(err)
+				return
+			}
+
+			err = s.Set(string(p))
+			if err != nil {
+				fyne.LogError("Failed to set string from web socket", err)
+			}
+		}
+	}()
+	ret := &webSocketString{String: s, conn: conn}
+	return ret, nil
+}
+
+func (s *webSocketString) Close() error {
+	if s.conn == nil {
+		return nil
+	}
+
+	return s.conn.Close()
+}

go.mod

@@ -4,6 +4,7 @@ go 1.14
 
 require (
 	fyne.io/fyne/v2 v2.1.0
+	github.com/gorilla/websocket v1.4.2
 	github.com/stretchr/testify v1.7.0
 	github.com/wagslane/go-password-validator v0.3.0
 )

go.sum

@@ -21,6 +21,8 @@ github.com/godbus/dbus/v5 v5.0.4 h1:9349emZab16e7zQvpmsbtjc18ykshndd8y2PG3sgJbA=
 github.com/godbus/dbus/v5 v5.0.4/go.mod h1:xhWf0FNVPg57R7Z0UbKHbJfkEywrmjJnf7w5xrFpKfA=
 github.com/goki/freetype v0.0.0-20181231101311-fa8a33aabaff h1:W71vTCKoxtdXgnm1ECDFkfQnpdqAO00zzGXLA5yaEX8=
 github.com/goki/freetype v0.0.0-20181231101311-fa8a33aabaff/go.mod h1:wfqRWLHRBsRgkp5dmbG56SA0DmVtwrF5N3oPdI8t+Aw=
+github.com/gorilla/websocket v1.4.2 h1:+/TMaTYc4QFitKJxsQ7Yye35DkWvkdLcvGKqM+x0Ufc=
+github.com/gorilla/websocket v1.4.2/go.mod h1:YR8l580nyteQvAITg2hZ9XVh4b55+EU/adAjf1fMHhE=
 github.com/jackmordaunt/icns v0.0.0-20181231085925-4f16af745526/go.mod h1:UQkeMHVoNcyXYq9otUupF7/h/2tmHlhrS2zw7ZVvUqc=
 github.com/josephspurrier/goversioninfo v0.0.0-20200309025242-14b0ab84c6ca/go.mod h1:eJTEwMjXb7kZ633hO3Ln9mBUCOjX2+FlTljvpl9SYdE=
 github.com/kr/pty v1.1.1/go.mod h1:pFQYn66WHrOpPYNljwOMqo10TkYh1fy3cYio2l3bCsQ=