Non-standard
This feature is non-standard and is not on a standards track. Do not use it on production sites facing the Web: it will not work for every user. There may also be large incompatibilities between implementations and the behavior may change in the future.
The Node.nodePrincipal read-only property returns the nsIPrincipal object representing current security context of the node.
Note: This property exists on all nodes (HTML, XUL, SVG, MathML, etc.), but only if the script trying to use it has chrome privileges.
Syntax
principalObj = element.nodePrincipal
Notes
This property is read-only; attempting to write to it will throw an exception. In addition, this property may only be accessed from privileged code.
Specification
Not in any specification.