Function collectResidual

packages/core/src/render3/instructions/styling.ts:551–571

* Collect all static values after the current `TNode.directiveStylingLast` index. * * Collect the remaining styling information which has not yet been collected by an existing * styling instruction. * * @param tData `TData` where the `DirectiveDefs` are stored. * @param tNode `TNode` which con

(
  tData: TData,
  tNode: TNode,
  isClassBased: boolean,
)

 * @param isClassBased `true` if `class` (`false` if `style`)
 */
function collectResidual(
  tData: TData,
  tNode: TNode,
  isClassBased: boolean,
): KeyValueArray<any> | null {
  let residual: KeyValueArray<any> | null | undefined = undefined;
  const directiveEnd = tNode.directiveEnd;
  ngDevMode &&
    assertNotEqual(
      tNode.directiveStylingLast,
      -1,
      'By the time this function gets called at least one hostBindings-node styling instruction must have executed.',
    );
  // We add `1 + tNode.directiveStart` because we need to skip the current directive (as we are
  // collecting things after the last `hostBindings` directive which had a styling instruction.)
  for (let i = 1 + tNode.directiveStylingLast; i < directiveEnd; i++) {
    const attrs = (tData[i] as DirectiveDef<any>).hostAttrs;
    residual = collectStylingFromTAttrs(residual, attrs, isClassBased) as KeyValueArray<any> | null;
  }
  return collectStylingFromTAttrs(residual, tNode.attrs, isClassBased) as KeyValueArray<any> | null;
}

/**
 * Collect the static styling information with lower priority than `hostDirectiveDef`.