ts
app.get('/track/stream', (req, res) => {
    const ticketId = req.query['ticket'] as string
    const ticket = validateTicket(ticketId)
    if (typeof ticket === 'string') return res.render('err.njk', { error: ticket, bare: true })
    
    const tracker = new RailwayTracker(ticketId, trains, routes, tickets)

    // Headers as per Server Sent Events spec
    res.setHeader('Cache-Control', 'no-cache')
    res.setHeader('Content-Type',  'text/event-stream')
    res.setHeader('Connection',    'keep-alive')
    res.flushHeaders()

    res.write('retry: 8000\n\n')

    const onReport = (e: Event) => {
        // @ts-ignore
        const r = e.detail as TrainReport
        console.log('sending')
        res.write('event: report\n' +
                  `data: ${nunjucks.render('track-stream.njk', { report: r })}\n\n`)
    }

    tracker.addEventListener('report', onReport)
    tracker.addEventListener('closed', function listener() {
        tracker.removeEventListener('report', onReport)
        tracker.removeEventListener('closed', listener)
        res.end()
    })
})

data:

ts
tracker.addEventListener('report', onReport)

HX-Location

app-canvas

hx-boost