jQuery addClass example

Change class name on click in jQuery

HTML

<button id="dl_all">download all</button>
<img class="dl"...

CSS

body {
  background: #20262E;
  padding: 20px;
  font-family: Helvetica;
}

#banner-message {
  background: #fff;
  border-radius: 4px;
  padding: 20px;
  font-size: 25px;
  text-align: center;
  transition: all 0.2s;
  margin: 0 auto;
  width: 300px;
}

button {
  background: #0084ff;
  border: none;
  border-radius: 5px;
  padding: 8px 14px;
  font-size: 15px;
  color: #fff;
}

#banner-message.alt {
  background: #0084ff;
  color: #fff;
  margin-top: 40px;
  width: 200px;
}

#banner-message.alt button {
  background: #fff;
  color: #000;
}

JavaScript

function download(data, file_name) {
	console.log(file_name)
  const a = document.createElement("a")
  a.href = data
  const extension = data.match(/^data:(.*?)\/(.*?);/)[2]
  a.setAttribute("download", file_name + "." + extension)
  a.style.display = "none"
  a.addEventListener("click", e => e.stopPropagation())
  document.body.appendChild(a)
  setTimeout(() => {
    a.click()
    document.body.removeChild(a) 
  }, 0)
}
function download_all() {
  [...document.getElementsByClassName("dl")]
    .forEach((img, i) => download(img.src, "img" + i))
}
document
  .getElementById("dl_all")
  .addEventListener("click", download_all)