TrustedTypePolicyFactory: isHTML() method

Limited availability

This feature is not Baseline because it does not work in some of the most widely-used browsers.

The isHTML() method of the TrustedTypePolicyFactory interface returns true if it is passed a valid TrustedHTML object.

Note: The purpose of the functions isHTML(), isScript(), and isScriptURL() is to check if the object is a valid TrustedType object, created by a configured policy.

Syntax

js
isHTML(value)

Parameters

value

A TrustedHTML object.

Return value

A boolean that is true if the object is a valid TrustedHTML object.

Examples

In the below example the constant html was created by a policy, and therefore isHTML() returns true. The second example is an attempt to fake an object, and the third is a string. Both of these will return false when passed to isHTML().

js
const html = policy.createHTML("<div>");
console.log(trustedTypes.isHTML(html)); // true;

const fake = Object.create(TrustedHTML.prototype);
console.log(trustedTypes.isHTML(fake)); // false

console.log(trustedTypes.isHTML("<div>plain string</div>")); // false

Specifications

Specification
Trusted Types
# dom-trustedtypepolicyfactory-ishtml

Browser compatibility

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