void allowTagExtension(
String tagName,
String baseName,
{UriPolicy uriPolicy,
Iterable<String> attributes,
Iterable<String> uriAttributes}
)

Allow custom tag extensions with the specified type name and specified attributes.

This will allow tag extensions (such as <div is="x-foo"></div>), but will not allow custom tags. Use allowCustomElement to allow custom tags.

Source

/**
 * Allow custom tag extensions with the specified type name and specified
 * attributes.
 *
 * This will allow tag extensions (such as <div is="x-foo"></div>),
 * but will not allow custom tags. Use [allowCustomElement] to allow
 * custom tags.
 */
void allowTagExtension(String tagName, String baseName,
    {UriPolicy uriPolicy,
    Iterable<String> attributes,
    Iterable<String> uriAttributes}) {

  var baseNameUpper = baseName.toUpperCase();
  var tagNameUpper = tagName.toUpperCase();
  var attrs;
  if (attributes != null) {
    attrs =
        attributes.map((name) => '$baseNameUpper::${name.toLowerCase()}');
  }
  var uriAttrs;
  if (uriAttributes != null) {
    uriAttrs =
        uriAttributes.map((name) => '$baseNameUpper::${name.toLowerCase()}');
  }
  if (uriPolicy == null) {
    uriPolicy = new UriPolicy();
  }

  add(new _CustomElementNodeValidator(
      uriPolicy,
      [tagNameUpper, baseNameUpper],
      attrs,
      uriAttrs,
      true,
      false));
}