FAQ

How can I reference existing objects on canvas?

canvas.getObjects() returns an array of all objects on canvas; `canvas.item(n)` returns n-th object on canvas (where indexing is associated with z-order)

How can I change object's properties?

Using fabric.Object#set method (e.g.: rect.set('width', 100).set('height', 50) or rect.set({ width: 100, height: 50 }))

How can I change background color of canvas area?

Using "backgroundColor" property of fabric.Element instance. E.g.: canvas.backgroundColor = 'red' or canvas.backgroundColor = rgba(0, 255, 0, 0.5)