javascript - Download image from data base to canvas -

i have problem. first add image computer canvas

document.getelementbyid('imgloader').onchange = function handleimage(e) { var reader = new filereader(); reader.onload = function (event) { console.log('fdsf');     var imgobj = new image();     imgobj.src = event.target.result;     imgobj.onload = function () {         // start fabricjs stuff         var newsize = scalesize(300, 300, imgobj.width, imgobj.height);         imgobj.width = newsize[0];         imgobj.height = newsize[1];         var image = new fabric.image(imgobj);         image.set({             left: 0,             top: 0,             angle: 20,             padding: 10,             cornersize: 10         });         //image.scale(getrandomnum(0.1, 0.25)).setcoords();         canvas.add(image);          // end fabricjs stuff     }  } reader.readasdataurl(e.target.files[0]); 

}

next save data base string

json.stringify(canvas.tojson()) 

in data base see it:

{"objects":[{"type":"image","originx":"left","originy":"top","left":0,"top":0,"width":300,"height":155,"fill":"rgb(0,0,0)","stroke":null,"strokewidth":1,"strokedasharray":null,"strokelinecap":"butt","strokelinejoin":"miter","strokemiterlimit":10,"scalex":1,"scaley":1,"angle":20,"flipx":false,"flipy":false,"opacity":1,"shadow":null,"visible":true,"clipto":null,"backgroundcolor":"","src":"data:image/jpeg;base64,//.../z","filters":[],"crossorigin":""}],"background":""} 

my problem here. when want download img canvas. dont see img. why?

i use method:

canvas.loadfromjson(data["img"][i]) document.getelementbyid("test").innerhtml=canvas.tosvg(); 

try:

canvas.loadfromjson(json, canvas.renderall.bind(canvas)); 

json here variable has string json:

json = json.stringify(canvas.tojson()); 

it should work. made jsfiddle. canvas.clear() there clear see load json works.