Document: parseHTML() static method

input

A string defining HTML to be sanitized and injected into the shadow root.

options Optional

An options object with the following optional parameters:

sanitizer

A Sanitizer or SanitizerConfig object which defines what elements of the input will be allowed or removed, or the string "default" for the default sanitizer configuration. Note that generally a "Sanitizer is expected to be more efficient than a SanitizerConfig if the configuration is to reused. If not specified, the XSS-safe default sanitizer configuration is used.

A Document.

TypeError

This is thrown if options.sanitizer is passed a:

• non-normalized SanitizerConfig (one that includes both "allowed" and "removed" configuration settings).
• string that does not have the value "default".
• value that is not a Sanitizer, SanitizerConfig, or string.

The parseHTML() method parses and sanitize a string of HTML in order to create a new Document instance that is XSS-safe. The resulting Document will have a content type of "text/html", a character set of UTF-8, and a URL of "about:blank".

If no sanitizer configuration is specified in the options.sanitizer parameter, parseHTML() is used with the default Sanitizer configuration. This configuration allows all elements and attributes that are considered XSS-safe, thereby disallowing entities that are considered unsafe. A custom sanitizer or sanitizer configuration can be specified to choose which elements, attributes, and comments are allowed or removed. Note that even if unsafe options are allowed by the sanitizer configuration, they will still be removed when using this method (which implicitly calls Sanitizer.removeUnsafe()).

The input HTML may include declarative shadow roots. If the string of HTML defines more than one declarative shadow root in a particular shadow host then only the first ShadowRoot is created — subsequent declarations are parsed as <template> elements within that shadow root.

parseHTML() should be used instead of Document.parseHTMLUnsafe(), unless there is a specific need to allow unsafe elements and attributes. If the HTML to be parsed doesn't need to contain unsafe HTML entities, then you should use Document.parseHTML().

Note that since this method always sanitizes input strings of XSS-unsafe entities, it is not secured or validated using the Trusted Types API.

• Document.parseHTMLUnsafe()
• Element.setHTML() and Element.setHTMLUnsafe()
• ShadowRoot.setHTML() and ShadowRoot.setHTMLUnsafe()
• DOMParser.parseFromString() for parsing HTML or XML into a DOM tree
• HTML Sanitizer API