Electron IPC Channel Pub/Sub

Problem: 

While working on an Electron program that has multiple windows, I knew I needed the windows to be able to talk to each other. This is usually done with each window establishing a connection with the main script, and then the main script facilitating the communication between each window. This way works fine, but seems very manual and then became a bit more convoluted when multiple windows need to get the same information. 

Solution:

To solve this, I decided to implement a very simple subscription style connection:

const ChannelSubscribeAction = 'channel-subscribe';

const ChannelUnsubscribeAction = 'channel-unsubscribe';

const ErrorDataChannel = 'error-data';

// handle channel subscriptions

const channelWindowMap = new Map();

ipcMain.on(ChannelSubscribeAction, (event, channel) => {

    if (!channelWindowMap.has(channel)){

        channelWindowMap.set(channel, new Set());

        ipcMain.on(channel, (event, data) => handleChannelEvent(channel, event, data));

    }

    channelWindowMap.set(channel, channelWindowMap.get(channel).add(event.sender));

});

ipcMain.on(ChannelUnsubscribeAction, (event, channel) => {

    if (!channelWindowMap.has(channel)) return;

    channelWindowMap.set(channel, channelWindowMap.get(channel).remove(event.sender));

});

function handleChannelEvent(channel, event, data){

    if (!channelWindowMap.has(channel)) return;

   

    channelWindowMap.get(channel).forEach((webContentWin) => {

        webContentWin.send(channel, data);

        // if we get an error, open dev tools for the window that had the error

        if (channel == ErrorDataChannel){

            event.sender.webContents.openDevTools();

        }

    });

}

This allows for any window to subscribe to any channel, and then later unsubscribe if desired. In my code here, I also am detecting when script errors occur and triggering the dev tools to open for that specific window to have a closer look. 

The channels are all defined in a single simple enum file and then when each window starts up, it calls in: 

ipcRenderer.send(ChannelSubscribeAction, Channels.MainChannel);

Note: There may be some vulnerabilities that come with this approach.