examples.waku.org/relay-js/index.html

164 lines
5.9 KiB
HTML

<!DOCTYPE html>
<html lang='en'>
<head>
<meta charset='UTF-8' />
<meta content='width=device-width, initial-scale=1.0' name='viewport' />
<title>JS-Waku Chat</title>
</head>
<body>
<div><h1>Waku Node Status</h1></div>
<div id='status'></div>
<input id='textInput' placeholder='Type your message here' type='text'>
<button id='sendButton' onclick='sendMessage();' type='button'>Send Message
</button>
<div><h1>Messages</h1></div>
<div id='messages'></div>
<script
src='https://unpkg.com/js-waku@latest/build/umd/js-waku.min.bundle.js'></script>
<script>
/**
* Demonstrate usage of js-waku in the browser. Use relay, gossip sub protocol to send and receive messages.
* Recommended payload is protobuf. Using simple utf-8 string for demo purposes only.
*
* - API documentation: https://js-waku.wakuconnect.dev/
* - Guides: https://docs.wakuconnect.dev/
*
* Note: open this HTML in two different browsers to experience decentralized communication.
* A node will not show its own messages, this can be changed by modifying the `Waku.create` call:
*
* Waku.create({
* bootstrap: {default: true}, libp2p: {
* config: {
* pubsub: {
* enabled: true,
* emitSelf: true,
* },
* },
* },
* })
*
*/
const { Waku, WakuMessage } = jswaku;
const statusDiv = document.getElementById('status');
const messagesDiv = document.getElementById('messages');
const textInput = document.getElementById('textInput');
const sendButton = document.getElementById('sendButton');
// Keep it disabled until Waku node is ready
textInput.disabled = true;
sendButton.disabled = true;
// Every Waku Message has a content topic that categorizes it.
// It is always encoded in clear text.
// Recommendation: `/dapp-name/version/functionality/codec`
// We recommend to use protobuf as codec (`proto`), this demo uses utf-8
// for simplicity's sake.
const contentTopic = '/relay-demo/1/message/utf-8';
// Function to be used to send the text input over Waku.
let sendMessage = () => {
};
try {
statusDiv.innerHTML = '<p>Starting</p>';
// Create and starts a Waku node.
// `default: true` bootstraps by connecting to pre-defined/hardcoded Waku nodes.
// We are currently working on migrating this method to DNS Discovery.
//
// https://js-waku.wakuconnect.dev/classes/waku.Waku.html#create
Waku.create({ bootstrap: { default: true } }).catch(e => {
statusDiv.innerHTML = 'Error';
console.log('Issue starting Waku node', e);
}
).then(wakuNode => {
// Had a hook to process all incoming messages on a specified content topic.
//
// https://js-waku.wakuconnect.dev/classes/waku_relay.WakuRelay.html#addObserver
wakuNode.relay.addObserver((wakuMessage) => {
// Checks there is a payload on the message.
// Waku Message is encoded in protobuf, in proto v3 fields are always optional.
//
// https://js-waku.wakuconnect.dev/classes/waku_message.WakuMessage.html#payload
if (!wakuMessage.payload)
return;
// Helper method to decode the payload to utf-8. A production dApp should
// use `wakuMessage.payload` (Uint8Array) which enables encoding a data
// structure of their choice.
//
// https://js-waku.wakuconnect.dev/classes/waku_message.WakuMessage.html#payloadAsUtf8
const text = wakuMessage.payloadAsUtf8;
messagesDiv.innerHTML = `<p>${text}</p><br />` + messagesDiv.innerHTML;
}, [contentTopic]);
statusDiv.innerHTML = '<p>Connecting to a peer</p>';
// Best effort method that waits for the Waku node to be connected to remote
// waku nodes (peers) and for appropriate handshakes to be done.
//
// https://js-waku.wakuconnect.dev/classes/waku.Waku.html#waitForRemotePeer
wakuNode.waitForRemotePeer()
.catch((e) => {
statusDiv.innerHTML = 'Failed to connect to peers: ' + e.toString();
})
.then(() => {
// We are now connected to a remote peer, let's define the `sendMessage`
// function that sends the text input over Waku Relay, the gossipsub
// protocol.
sendMessage = () => {
const text = textInput.value;
// Reset the text input.
textInput.value = null;
// Helper functions are available to create a Waku Message.
// These functions also provide native symmetric, asymmetric encryption,
// signing and signature verification. Check the `Options` object for details:
// https://js-waku.wakuconnect.dev/interfaces/waku_message.Options.html
//
// `WakuMessage.fromBytes` should be preferred for a production dApp to
// serialize a data structure.
//
// https://js-waku.wakuconnect.dev/classes/waku_message.WakuMessage.html#fromUtf8String
WakuMessage.fromUtf8String(text, contentTopic).catch(e => console.log('Error encoding message', e)).then(
wakuMessage => {
// Once the message is constructed, send it over Waku Relay.
//
// https://js-waku.wakuconnect.dev/classes/waku_relay.WakuRelay.html#send
wakuNode.relay.send(wakuMessage).catch((e) => {
console.log('Error sending message', e);
}).then(() => {
console.log('Message sent', text);
});
}
);
};
// Ready to send & receive messages, enable text input.
textInput.disabled = false;
sendButton.disabled = false;
statusDiv.innerHTML = '<p>Ready!</p>';
});
});
} catch (e) {
timestampDiv.innerHTML = 'Failed to start application';
console.log(e);
}
</script>
</body>
</html>