Function classKeyValueArraySet

packages/core/src/render3/instructions/styling.ts:775–785

(keyValueArray: KeyValueArray<any>, key: unknown, value: any)

 * @param value The value to set.
 */
export function classKeyValueArraySet(keyValueArray: KeyValueArray<any>, key: unknown, value: any) {
  // We use `classList.add` to eventually add the CSS classes to the DOM node. Any value passed into
  // `add` is stringified and added to the `class` attribute, e.g. even null, undefined or numbers
  // will be added. Stringify the key here so that our internal data structure matches the value in
  // the DOM. The only exceptions are empty strings and strings that contain spaces for which
  // the browser throws an error. We ignore such values, because the error is somewhat cryptic.
  const stringKey = String(key);
  if (stringKey !== '' && !stringKey.includes(' ')) {
    keyValueArraySet(keyValueArray, stringKey, value);
  }
}

/**
 * Update map based styling.