Reference Error : patternSourceCanvas is not defined fabric js loadFromJSON

I am applying pattern to SVG, and using toJSON save data in database. When I am trying to load that on canvas using loadFromJSON its throwing error pattern source is undefined.

Here is my code I am using to set pattern.

fabric.Image.fromURL(url,function(img){
            img.scaleToWidth(width);
            if (angle > 0) img.set('angle', angle);
            var patternSourceCanvas = new fabric.StaticCanvas();
            patternSourceCanvas.add(img);
            patternSourceCanvas.renderAll();
            var pattern = new fabric.Pattern({
                source: function() {
                    patternSourceCanvas.setDimensions({
                        width:img.getWidth() + padding,
                        height:img.getHeight() + padding
                    });
                    patternSourceCanvas.renderAll();
                    return patternSourceCanvas.getElement();
                },
                repeat: isrepeat,
                src: url,
            });

            if(left_offset > 0) { pattern.offsetX = (left_offset); } else{ pattern.offsetX = 0;}
            if(top_offset > 0) { pattern.offsetY = (top_offset); } else { pattern.offsetY = 0;}
            var applyPatternto = 0;
            if(activeView != 1){ applyPatternto = $("#sel_applyPatternto").val(); }
            currentElement.paths[applyPatternto].setFill(pattern);
            canvas.renderAll();
        });

to load save JSON and load from JSON I am using following,

var frontJson  = JSON.stringify(canvas.toJSON());

while loading from JSON I also add delay to check same issue,

canvas.loadFromJSON(frontJson);
    setTimeout(function(){
        canvas.renderAll.bind(canvas);  
 },3000);