JavaScript: base64 encode and decode

by Emmanuel Garcia

HTML

<script type="text/javascript" src="http://ajax.googleapis.com/ajax/libs/jquery/1.8.3/jquery.min.js"></script>
    <script type="text/javascript" src="http://cdn.rawgit.com/niklasvh/html2canvas/master/dist/html2canvas.min.js"></script>


        <div>
            <table id="dvTable">
                <tr><td>ID</td><td>Name</td></tr>
                <tr><td>1001</td><td>AAA</td></tr>
                <tr><td>1002</td><td>BBB</td></tr>
            </table>
        </div>
        <div>
            <asp:HiddenField ID="hfImageData" runat="server" />
            <asp:Button ID="btnExport" Text="Export to Image" runat="server" UseSubmitBehavior="false"
                OnClick="btnExport_Click" OnClientClick="return ConvertToImage(this)" />
        </div>

JavaScript

function ConvertToImage(btnExport) {
            html2canvas($("#dvTable")[0]).then(function (canvas) {
                var base64 = canvas.toDataURL();
                $("[id*=hfImageData]").val(base64);
                __doPostBack(btnExport.name, "");
            });
            return false;
        }