Load from JSON with dynamic patterns, patternSourceCanvas is not defined error return by the serialize JSON data - angularjs

Question

I am trying to save Fabric.js canvas and reload it using loadFromJson. But I am getting error patternSourceCanvas is not defined. I thought I should make it global so I removed var.
How to set the global variable in Fabric JS and use var patternSourceCanvas?
When I use the code below, then everything is working fine and the JSON is loaded easily.
var t = https://image.freepik.com/free-photo/roof-texture_21206171.jpg
fabric.util.loadImage(t, function(t) {
var svg_width = i.width;
console.log('svg widh' + i.width + 'svg height' + i.height);
console.log('img width t'+ t.width + ' img height' + t.height);
if(svg_width >= 300){
if (i.isSameColor && i.isSameColor() || !i.paths) {
i.setPatternFill({
source: t, repeat: 'repeat', offsetX:200 , offsetY : -110 // working
}), e.fabric.renderAll();
console.log('in if image 300 up ', t);
} else if (i.paths){
for (var r = 0; r < i.paths.length; r++)
i.paths[r].setPatternFill({
source: t, repeat: 'repeat' , offsetX: -100 , offsetY:-110
}), e.fabric.renderAll();
console.log('in image elseeee 300 up ', t);
}
}
})
But when I fill some other new shape with the new patternSourceCanvas variable then it's not working. Kindly help me with dynamic patterns.
var t = https://image.freepik.com/free-photo/roof-texture_21206171.jpg
fabric.Image.fromURL(t, function (img) {
img.scaleToHeight(200);
var patternSourceCanvas = new fabric.StaticCanvas();
patternSourceCanvas.add(img);
patternSourceCanvas.renderAll();
var pattern = new fabric.Pattern({
source: function() {
patternSourceCanvas.setDimensions({
width: img.getScaledWidth() ,
height: img.getScaledHeight()
});
patternSourceCanvas.renderAll();
return patternSourceCanvas.getElement();
},
repeat: r
});
console.log('pattern', pattern);
//p.set('fill', pattern);
canvas.renderAll();
if (i.isSameColor && i.isSameColor() || !i.paths) {
i.setPatternFill(pattern);
} else if(i.paths) {
for (var r = 0; r < i.paths.length; r++) {
i.paths[r].setPatternFill(pattern);
}
}
e.fabric.renderAll();
});

Answer 1

You need to put patternSourceCanvas to global scope/ scope where loadFromJSON can access patternSourceCanvas. Else you can use cors enabled image directly.
DEMO
var imageUrl = 'https://upload.wikimedia.org/wikipedia/commons/2/22/Wikimapia_logotype.svg';
var canvas = new fabric.Canvas('canvas');
var rect = new fabric.Rect({
width: 200,
height: 200,
strokeWidth: 2,
stroke: '#000'
})
canvas.add(rect);
fabric.Image.fromURL(imageUrl, function(img) {
img.scaleToHeight(200);
var patternSourceCanvas = new fabric.StaticCanvas();
patternSourceCanvas.add(img);
patternSourceCanvas.setDimensions({
width: img.getScaledWidth(),
height: img.getScaledHeight()
});
patternSourceCanvas.renderAll();
var pattern = new fabric.Pattern({
source: patternSourceCanvas.getElement()
},
function(patternObj) {
rect.fill = patternObj;
rect.dirty = true;
canvas.renderAll();
});
}, {
crossOrigin: 'annonymous'
});
function loadfromjson() {
var json = canvas.toJSON();
canvas.clear();
setTimeout(function() {
canvas.loadFromJSON(json, canvas.renderAll.bind(canvas));
}, 1000)
}
canvas{
border:2px solid #000;
}
<canvas id="canvas" width="300" height="300"></canvas><br>
<button onclick="loadfromjson()">loadfromjson </button>
<script src='https://rawgit.com/kangax/fabric.js/master/dist/fabric.js'></script>