Function isCssClassMatching

packages/core/src/render3/node_selector_matcher.ts:30–72

* Search the `TAttributes` to see if it contains `cssClassToMatch` (case insensitive) * * @param tNode static data of the node to match * @param attrs `TAttributes` to search through. * @param cssClassToMatch class to match (lowercase) * @param isProjectionMode Whether or not class matching sho

(
  tNode: TNode,
  attrs: TAttributes,
  cssClassToMatch: string,
  isProjectionMode: boolean,
)

 *    addition to the `AttributeMarker.Classes`.
 */
function isCssClassMatching(
  tNode: TNode,
  attrs: TAttributes,
  cssClassToMatch: string,
  isProjectionMode: boolean,
): boolean {
  ngDevMode &&
    assertEqual(
      cssClassToMatch,
      cssClassToMatch.toLowerCase(),
      'Class name expected to be lowercase.',
    );
  let i = 0;
  if (isProjectionMode) {
    for (; i < attrs.length && typeof attrs[i] === 'string'; i += 2) {
      // Search for an implicit `class` attribute and check if its value matches `cssClassToMatch`.
      if (
        attrs[i] === 'class' &&
        classIndexOf((attrs[i + 1] as string).toLowerCase(), cssClassToMatch, 0) !== -1
      ) {
        return true;
      }
    }
  } else if (isInlineTemplate(tNode)) {
    // Matching directives (i.e. when not matching for projection mode) should not consider the
    // class bindings that are present on inline templates, as those class bindings only target
    // the root node of the template, not the template itself.
    return false;
  }

  // Resume the search for classes after the `Classes` marker.
  i = attrs.indexOf(AttributeMarker.Classes, i);
  if (i > -1) {
    // We found the classes section. Start searching for the class.
    let item: TAttributes[number];
    while (++i < attrs.length && typeof (item = attrs[i]) === 'string') {
      if (item.toLowerCase() === cssClassToMatch) {
        return true;
      }
    }
  }
  return false;
}

/**
 * Checks whether the `tNode` represents an inline template (e.g. `*ngFor`).