无法使用fabric.js导出和加载svg

Question

我想导出使用fabric.js创建的svg，所以我正在按照加载并保存

var canvas = this.__canvas = new fabric.Canvas('c');
  fabric.Object.prototype.transparentCorners = false;

  var padding = 0;

  fabric.Image.fromURL('http://netdna.webdesignerdepot.com/uploads/album_artwork/t2-7.jpg', function(img) {

    img.scaleToWidth(100);

    var patternSourceCanvas = new fabric.StaticCanvas();
    patternSourceCanvas.add(img);

    var pattern = new fabric.Pattern({
      source: function() {
        patternSourceCanvas.setDimensions({
          width: img.getWidth() + padding,
          height: img.getHeight() + padding
        });
        return patternSourceCanvas.getElement();
      },
      repeat: 'repeat'
    });

    canvas.add(new fabric.Polygon([
      {x: 185, y: 0},
      {x: 250, y: 100},
      {x: 385, y: 170},
      {x: 0, y: 245} ], {
        left: 0,
        top: 200,
        angle: -30,
        fill: pattern
      }));

   $("#load").click(function(){
     canvas.loadFromJSON(json, function() {
     alert(' this is a callback. invoked when canvas is loaded! ');
});

});

  });


 $("#clear").click(function() {
  // clear canvas
canvas.clear(); 
}); 


 $("#remove_selected").click(function() {
// remove currently selected object
canvas.remove(canvas.getActiveObject());
}); 


$("#add_text").click(function(){
   canvas.add(new fabric.Text('Hello Text!', { 
          fontFamily: 'Tahoma', 
          left: 400,
          top: 225,
          fontSize: 80,
          textAlign: "left",
          fill:"#FF0000"  // Set text color to red
      })); 
});


 $("#add_rect").click(function() {
// add red rectangle
canvas.add(new fabric.Rect({
width: 50,
height: 50,
left: 50,
top: 50,
fill: 'rgb(255,0,0)'
}));
}); 

 $("#add_circle").click(function() {
// add green, half-transparent circle
canvas.add(new fabric.Circle({
radius: 40,
left: 50,
top: 50,
fill: 'rgb(0,255,0)',
opacity: 0.5
}));
}); 


 $("#add_line").click(function() {
// add green, half-transparent circle
canvas.add(new fabric.Line({
radius: 40,
left: 50,
top: 50,
fill: 'rgb(0,255,0)',
opacity: 0.5
}));



}); 

var svgSrc = "image/upload/54b9ab31a3fb5.png";

$("#loadSVG").click(function(){
     fabric.loadSVGFromURL(svgSrc, function (object) {
       var group = new fabric.PathGroup(object, { 
          left: 165, 
          top: 100, 
          width: 295, 
          height: 211,


        });                   
         //set source path for svg
         group.setSourcePath(svgSrc);    

        canvas.add(group);  
        canvas.renderAll(); 
});          

});


$("#exportSVG").click(function(){


    var json = JSON.stringify(canvas.toDatalessJSON());

$("body").append("
<div>
"+json+"
</di>
");

      canvas.loadFromJSON(json, function() {
  alert(' this is a callback. invoked when canvas is loaded! ');
});


});
$("#exporntSVG").click(function(){
group.fillColor = "#FF0000";
canvas.renderAll(); 
});


$("#save").click(function(){

}); 

但它对我不起作用，我可以看到导出的svg为JSON，但我无法使用loadFromJSON将其加载回svg并获得{{1}作为错误

示例小提琴：fiddle