a[download] in HTML5

by zoho

HTML

<div><input type="button" id="savetext" value="Save"/></div>
<textarea id="sometext">Hello World!</textarea>

CSS

#savetext {
  width: 40px;
}

JavaScript

function doSave(value, type, name) {
    var blob;
    if (typeof window.Blob == "function") {
        blob = new Blob([value], {type: type});
    } else {
        var BlobBuilder = window.BlobBuilder || window.MozBlobBuilder || window.WebKitBlobBuilder || window.MSBlobBuilder;
        var bb = new BlobBuilder();
        bb.append(value);
        blob = bb.getBlob(type);
    }
    var URL = window.URL || window.webkitURL;
    var bloburl = URL.createObjectURL(blob);
    var anchor = document.createElement("a");
    if ('download' in anchor) {
        anchor.style.visibility = "hidden";
        anchor.href = bloburl;
        anchor.download = name;
        document.body.appendChild(anchor);
        //var evt = document.createEvent("Event");
        //var evt = document.createEvent("UIEvents");
        var evt = document.createEvent("MouseEvents");
        evt.initEvent("click", true, true);
        //evt.initUIEvent("click", true, true, document.defaultView, 0);
        //evt.initMouseEvent("click", true, true, document.defaultView, 0, 0, 0, 0, 0, false, false, false, false, 0, null);
        anchor.dispatchEvent(evt);
        document.body.removeChild(anchor);
        /*
        var a = document.createElement('a');
        a.href = bloburl;
        a.download = name;
        a.textContent = 'Download';
        document.body.appendChild(a);
        */
    } else if (navigator.msSaveBlob) {
        navigator.msSaveBlob(blob, name);
    } else {
        location.href = bloburl;
    }
}

var savebtn = document.getElementById("savetext"),
    textout = document.getElementById("sometext");
savebtn.onclick = function() {
    doSave(textout.value, "text/latex", "hello.tex"); 
};