Function getAllChildBuilders

packages/forms/signals/src/schema/logic_node.ts:469–501

* Gets all of the builders that contribute logic to the given child of the parent builder. * This function recursively traverses the builder hierarchy. * @param builder The parent `AbstractLogicNodeBuilder`. * @param key The property key of the child. * @returns An array of objects, each contain

(
  builder: AbstractLogicNodeBuilder,
  key: PropertyKey,
)

 * @returns An array of objects, each containing a `LogicNodeBuilder` for the child and any associated predicates.
 */
function getAllChildBuilders(
  builder: AbstractLogicNodeBuilder,
  key: PropertyKey,
): {builder: LogicNodeBuilder; predicates: Predicate[]}[] {
  if (builder instanceof LogicNodeBuilder) {
    return builder.all.flatMap(({builder, predicate}) => {
      const children = getAllChildBuilders(builder, key);
      if (predicate) {
        return children.map(({builder, predicates}) => ({
          builder,
          predicates: [...predicates, predicate],
        }));
      }
      return children;
    });
  } else if (builder instanceof NonMergeableLogicNodeBuilder) {
    return [
      // DYNAMIC logic always comes first for any individual `NonMergeableLogicNodeBuilder`.
      // This assumption is guaranteed by the behavior of `LogicNodeBuilder.getChild`.
      // Therefore we can return all of the DYNAMIC logic, followed by all of the property-specific
      // logic.
      ...(key !== DYNAMIC && builder.children.has(DYNAMIC)
        ? [{builder: builder.getChild(DYNAMIC), predicates: []}]
        : []),
      ...(builder.children.has(key) ? [{builder: builder.getChild(key), predicates: []}] : []),
    ];
  } else {
    throw new RuntimeError(
      RuntimeErrorCode.UNKNOWN_BUILDER_TYPE,
      ngDevMode && 'Unknown LogicNodeBuilder type',
    );
  }
}

/**
 * Creates the full `Logic` for a given builder.