selfAddr & selfName

selfName

window.webxdc.selfName

selfName is the nick or display name for the user which the webxdc application may show in its user interface.

selfAddr

window.webxdc.selfAddr

A string ("unique ID") identifying the user in the current webxdc application. Every user of a webxdc application must get a different selfAddr. The selfAddr must be the same if the webxdc is started again later for the same user, on the same or on a different device. The same user opening a different webxdc application, however, SHOULD have a different selfAddr to avoid linkability between apps: even if a web app manipulates users to share selfAddr values via copy+paste to another web app, addresses between the two web apps should not be linkable.

Note that selfAddr

• has no meaning outside the webxdc application,

• should not be shown in the user interface of the webxdc application (use selfName instead).

Example using selfAddr and selfName

Here is a simple chat app that sends out a reply using the display names but uses the addresses for notifications.

// Receive a message from anyone in the chat
let users = new Set();

setUpdateListener((update) => {
    const prompt = `${update.payload.senderName} (${update.payload.senderAddr}):`;
    users.add(update.payload.senderAddr);
    console.log(`${prompt} ${update.message}`);
})

// start some user interface which calls the following function for
// message sending

sendMessage(text) => {
    let payload = {
        senderAddr: webxdc.selfAddr,
        senderName: webxdc.selfName,
        message: text
    };

    // notify all users who ever sent a message in the chat app
    let notify = {};
    for (const addr of users) {
        notify[addr] = `new message from ${webxdc.selfName}`;
    }

    sendUpdate({
        payload: payload,
        notify: notify
    })
})