[gjs: 1/2] add websocket client example

[Philip Chimento <pchimento src gnome org>]

commit b5ce50eb1749cc8cee1aaa4ebd99428457a47784
Author: Sonny Piers <sonny fastmail net>
Date:   Fri Sep 20 16:33:49 2019 +0200

    add websocket client example

 examples/websocket-client.js | 52 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 52 insertions(+)
---
diff --git a/examples/websocket-client.js b/examples/websocket-client.js
new file mode 100644
index 00000000..84ca48ad
--- /dev/null
+++ b/examples/websocket-client.js
@@ -0,0 +1,52 @@
+// This is an example of a WebSocket client in Gjs using libsoup
+// https://developer.gnome.org/libsoup/stable/libsoup-2.4-WebSockets.html
+
+const Soup = imports.gi.Soup;
+const GLib = imports.gi.GLib;
+const byteArray = imports.byteArray;
+
+const loop = GLib.MainLoop.new(null, false);
+
+const session = new Soup.Session();
+const message = new Soup.Message({
+    method: 'GET',
+    uri: Soup.URI.new('wss://echo.websocket.org'),
+});
+
+session.websocket_connect_async(message, 'origin', [], null, websocket_connect_async_callback);
+
+function websocket_connect_async_callback(_session, res) {
+    let connection;
+
+    try {
+        connection = session.websocket_connect_finish(res);
+    } catch (e) {
+        logError(e);
+        loop.quit();
+        return;
+    }
+
+    connection.connect('closed', () => {
+        log('closed');
+        loop.quit();
+    });
+
+    connection.connect('error', (self, err) => {
+        logError(err);
+        loop.quit();
+    });
+
+    connection.connect('message', (self, type, data) => {
+        if (type !== Soup.WebsocketDataType.TEXT)
+            return;
+
+        const str = byteArray.toString(byteArray.fromGBytes(data));
+        log(`message: ${str}`);
+        connection.close(Soup.WebsocketCloseCode.NORMAL, null);
+    });
+
+    log('open');
+    connection.send_text('hello');
+}
+
+loop.run();