Function resolveDirectives

packages/core/src/render3/view/directives.ts:58–99

(
  tView: TView,
  lView: LView,
  tNode: TElementNode | TContainerNode | TElementContainerNode,
  localRefs: string[] | null,
  directiveMatcher: DirectiveMatcherStrategy,
)

 * Resolve the matched directives on a node.
 */
export function resolveDirectives(
  tView: TView,
  lView: LView,
  tNode: TElementNode | TContainerNode | TElementContainerNode,
  localRefs: string[] | null,
  directiveMatcher: DirectiveMatcherStrategy,
): void {
  // Please make sure to have explicit type for `exportsMap`. Inferred type triggers bug in tsickle.
  ngDevMode && assertFirstCreatePass(tView);

  const exportsMap: Record<string, number> | null = localRefs === null ? null : {'': -1};
  const matchedDirectiveDefs = directiveMatcher(tView, tNode);

  if (matchedDirectiveDefs !== null) {
    let directiveDefs = matchedDirectiveDefs;
    let hostDirectiveDefs: HostDirectiveDefs | null = null;
    let hostDirectiveRanges: HostDirectiveRanges | null = null;

    for (const def of matchedDirectiveDefs) {
      if (def.resolveHostDirectives !== null) {
        [directiveDefs, hostDirectiveDefs, hostDirectiveRanges] =
          def.resolveHostDirectives(matchedDirectiveDefs);
        break;
      }
    }

    ngDevMode && assertNoDuplicateDirectives(directiveDefs);

    initializeDirectives(
      tView,
      lView,
      tNode,
      directiveDefs,
      exportsMap,
      hostDirectiveDefs,
      hostDirectiveRanges,
    );
  }
  if (exportsMap !== null && localRefs !== null) {
    cacheMatchingLocalNames(tNode, localRefs, exportsMap);
  }
}

/** Caches local names and their matching directive indices for query and template lookups. */
function cacheMatchingLocalNames(