将dygraph图表保存到我本地硬盘上的jpg图像中

Question

I am working with JavasSript Dygraphs chart. Everything is fine but what i need to do is to be able to save it on my local hard drive as an image. Below is my JavaScript code:

<script type="text/javascript">
 var img;
  g3 = new Dygraph(
   img = document.getElementById("graphdiv3"),
    "temperatures.csv",
    {
       rollPeriod: 9,
       showRoller: true,  
    }
    );
</script>

Here is my HTML code:

 <div>
     <div id='graphdiv3'></div>
 </div>

Answer 1

You can create a hidden image element in your page and export the image to the users disk but the issue is the downloaded file will not have any filetype. The user can open the downloaded file in any image viewer.

var img = document.getElementById(imgId);
Dygraph.Export.asPNG(graph, img);
window.location.href = img.src.replace('image/png','image/octet-stream');

This uses the dygraph-export library from this link http://cavorite.com/labs/js/dygraphs-export/

Answer 2

没有正式的方法可以做到这一点，但是dygraphs用户已经做了一些工作： https ：//groups.google.com/d/topic/dygraphs-users/whcMjtBE7s0/discussion