How to check the canvas is empty or blank

[tkslabz]

Hello
I want check the event if user start to draw on canvas or not. Actually i don't want perform any operation if user not draw any content on canvas means if canvas is blank.
Thanks
Regards

[barkdoll]

I don't know if the functionality is built in to jSignature or not, but this answer may help you.

[TianqiHo]

var arr = $(sigDomClass).jSignature('getData', 'native');

use it