Syntax
非标准
该特性是非标准的，请尽量不要在生产环境中使用它！
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.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.