function updateImages() {
    for (let image of document.querySelectorAll('img')) {
        let url = new URL(image.src)
        url.searchParams.set("t", Date.now())
        image.src = url.toString()
    }
}

async function submit(event) {
    event.preventDefault()
    let form = event.target
    let data = new FormData(form)
    let url = form.action
    let method = form.method
    let headers = new Headers()
    let resp = await fetch(url, {method, headers, body: data})
    if (resp.ok) {
        updateImages()
    } else {
        let body = await resp.text()
        alert(`Error: ${resp.status} ${resp.statusText}\n\n${body}`)
    }
}

function init() {
    for (let f of document.querySelectorAll("form")) {
        f.addEventListener("submit", event => submit(event))
    }
}

if (document.readyState === 'loading') {
  document.addEventListener('DOMContentLoaded', init)
} else {
    init()
}