Question

How to create a custom Print Button Coach View?

Answer 1

There is no need to create a custom coach view for this since its a simple javascript invocation of the window.print() method, you can make a copy of the stock button and change the onclick() as following in the behaviour->view javascript

    button.onclick = function() {
        if (this.disabled == false) {
            var context = _this.context;
            if (context.options.allowMultipleClicks == undefined || !context.options.allowMultipleClicks.get("value")) {
                this.disabled = true;
                domClass.add(this, "BPMButton-disabled");
            }
            if (context.binding) {
                context.binding.set("value", true);
            }
            var _button = this;
            window.print();
            //context.trigger(function() {_button.disabled = false; domClass.remove(_button, "BPMButton-disabled");});
        }
    }

if you need to print certain div in the Coach, you can do that also by defining a div wrapper and passing the specified div to the invocation as specified at the following url

http://stackoverflow.com/questions/16894683/how-to-print-html-content-on-click-of-a-button-but-not-the-page