Fabric JS Rich Text with IText or TextBox

Question

I saw rich text examples on fabric js http://fabricjs.com/test/misc/itext.html but I don't understand how we can handle it. Is there an example about it?

My purpose is to create a content like this:

Answer 1

I found an example about it:

var iText2 = new fabric.IText('hello\nworld', {
  left: 50,
  top: 50,
  fontFamily: 'Helvetica',
  fill: '#333',
  lineHeight: 1.1,
  styles: {
    0: {
      0: { textDecoration: 'underline', fontSize: 80 },
      1: { textBackgroundColor: 'red' }
    },
    1: {
      0: { textBackgroundColor: 'rgba(0,255,0,0.5)' },
      4: { fontSize: 20 }
    }
  }
});