[TIPS] How to get Attribute/Field value without executionContext input

 [TIPS] How to get Attribute/Field value without executionContext input

In Dynaimcs 365 JavaScript, sometimes there is no executionContext  imput, for example, the JS called in ribbon button, or in a HTML webresouce. 

Before  Dynamics V9.0, you can use below to get an attribute/field value:

Xrm.Page.getControl("kc_signature1_base64").getValue();

But since V9.0, Xrm.Page has been deprecated although it's still available now.

I am not sure if below API has been deprecated, but it works well till now. 

var signature1 = window.parent.Xrm.Page.getAttribute("kc_signature1_base64").getValue();

Just for your reference.