Disable send button if no peer available

Yet keep it enabled if user tries to send a command.

Resolves #136

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ### Added
 - `WakuRelay.getPeers` method.
+- Use `WakuRelay.getPeers` in web chat app example to disable send button.
 
 ### Changed
 - Enable passing `string`s to `addPeerToAddressBook`.

examples/web-chat/src/MessageInput.tsx

@@ -34,11 +34,15 @@ export default function MessageInput(props: Props) {
     }
   };
 
+  // Enable the button if there are relay peers available or the user is sending a command
+  const activeButton =
+    (waku && waku.relay.getPeers().size !== 0) || inputText.startsWith('/');
+
   return (
     <TextComposer
       onKeyDown={keyPressHandler}
       onChange={messageHandler}
-      active={!!waku}
+      active={activeButton}
       onButtonClick={sendMessage}
     >
       <Row align="center">