How to uncompress file inside ZIP archive using HTML5 & JSZip

In our previous post How to read local ZIP in HTML5/Javascript using JSZip we provided an example of how to use JSZip to list files inside a local ZIP archive using HTML5.

This post will expand upon this in order to read the content of a file compressed inside a local ZIP archive file.

In this example, we’ll read a local ZIP file using HTML5 <input type="file"> and uncompress its content. We’ll read the word/document.xml file, so you can upload any .docx file to test that.

JSZip.loadAsync(ev.target.result).then(function(zip) {
    zip.file("word/document.xml").async("ArrayBuffer").then(function(data) {
        // data is an ArrayBuffer
        // TODO Your code goes here!
    })
}).catch(function(err) {
    console.error("Failed to open", filename, " as ZIP file:", err);
})

Full example

<html>
<body>
    <input type="file" id="myfile" onchange="onMyfileChange(this)" />

    <script src="https://unpkg.com/[email protected]/dist/jszip.js" type="text/javascript"></script>
    <script type="text/javascript">
        function onMyfileChange(fileInput) {
            if(fileInput.files[0] == undefined) {
                return ;
            }

            var filename = fileInput.files[0].name;
            var reader = new FileReader();
            reader.onload = function(ev) {
                JSZip.loadAsync(ev.target.result).then(function(zip) {
                    zip.file("word/document.xml").async("ArrayBuffer").then(function(data) {
                        // data is an ArrayBuffer
                        // TODO Your code goes here!
                    })
                }).catch(function(err) {
                    console.error("Failed to open", filename, " as ZIP file:", err);
                })
            };
            reader.onerror = function(err) {
                console.error("Failed to read file", err);
            }
            reader.readAsArrayBuffer(fileInput.files[0]);
        }
    </script>
</body>
</html>