TrustedTypePolicy

Available in workers

The TrustedTypePolicy interface of the Trusted Types API defines a group of functions which create TrustedType objects.

A TrustedTypePolicy object is created by TrustedTypePolicyFactory.createPolicy() to define a policy for enforcing security rules on input. Therefore, TrustedTypePolicy has no constructor.

Instance properties

• name Read only
  • : A string containing the name of the policy.

Instance methods

• TrustedTypePolicy.createHTML()
  • : Creates a TrustedHTML object.
• TrustedTypePolicy.createScript()
  • : Creates a TrustedScript object.
• TrustedTypePolicy.createScriptURL()
  • : Creates a TrustedScriptURL object.

Examples

In the below example we create a policy that will create TrustedHTML objects using createPolicy(). We can then use createHTML to create a sanitized HTML string to be inserted into the document.

The sanitized value can then be used with innerHTML to ensure that no new HTML elements can be injected.

<div id="myDiv"></div>

const escapeHTMLPolicy = trustedTypes.createPolicy("myEscapePolicy", {
  createHTML: (string) => string.replace(/</g, "&lt;"),
});

let el = document.getElementById("myDiv");
const escaped = escapeHTMLPolicy.createHTML("<img src=x onerror=alert(1)>");
console.log(escaped instanceof TrustedHTML); // true
el.innerHTML = escaped;

Specifications

Browser compatibility