You can use zip.js for this.
It does already have API for fetching contents to be zipped from HTTP (cf. zip.HttpReader constructor) and for writing generated zip on HTML5 filesystem (cf. zip.FileWriter constructor).
Here is an example using the filesystem API:
index.html
file:
<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8">
<title>Zip JSON data from the BBC into HTML5 FileSystem</title>
</head>
<body>
<script src="zip.js"></script>
<script src="zip-fs.js"></script>
<script src="zip-ext.js"></script>
<script src="example.js"></script>
</body>
</html>
example.js
file:
// create a zip virtual filesystem
var fs = new zip.fs.FS();
// add some files into the zip filesystem
// add the "bbc-music.json" file in the root directory
fs.root.addHttpContent("bbc-music.json",
"http://www.bbc.co.uk/programmes/genres/music.json");
// add the "bbc-learning.json" file in the root directory
fs.root.addHttpContent("bbc-learning.json",
"http://www.bbc.co.uk/programmes/genres/learning.json");
// create a file named "test.zip" in the root directory of the HTML5 filesystem
createFile("test.zip", function(fileEntry) {
// export the zip content into "test.zip" file
fs.root.exportFileEntry(fileEntry, function() {
console.log("done");
});
});
// function to create a file in the HTML5 temporary filesystem
function createFile(filename, callback) {
webkitRequestFileSystem(TEMPORARY, 4 * 1024 * 1024, function(fs) {
fs.root.getFile(filename, { create : true }, callback);
});
}