You can use JSZip.js, XMLHttpRequest(), Array.prototype.map() , Promise.all() to create .zip file when all requests for files have completed; use <a> element with download attribute set to objectURL of .zip file at JSZip .generateAsync() function, click on a element should display Save File dialog with created .zip as downloadable file.
<head>
<script src="https://stackoverflow.com/questions/37176397/jszip.js"></script>
<script>
window.onload = function() {
var zip = new JSZip();
var a = document.querySelector("a");
var urls = ["a.html", "b.html"];
function request(url) {
return new Promise(function(resolve) {
var httpRequest = new XMLHttpRequest();
httpRequest.open("GET", url);
httpRequest.onload = function() {
zip.file(url, this.responseText);
resolve()
}
httpRequest.send()
})
}
Promise.all(urls.map(function(url) {
return request(url)
}))
.then(function() {
console.log(zip);
zip.generateAsync({
type: "blob"
})
.then(function(content) {
a.download = "folder" + new Date().getTime();
a.href = URL.createObjectURL(content);
a.innerHTML = "download " + a.download;
});
})
}
</script>
</head>
<body>
<a href="" download>download</a>
</body>