static Object _resolveFrom()

in packages/rfw/lib/src/flutter/runtime.dart [576:658]
80 lines of code
21 McCabe index (conditional complexity)

  static Object _resolveFrom(Object root, List<Object> parts, _StateResolverCallback stateResolver, _DataResolverCallback dataResolver) {
    int index = 0;
    Object current = root;
    while (true) {
      if (current is DataReference) {
        if (index < parts.length) {
          current = current.constructReference(parts.sublist(index));
          index = parts.length;
        }
        current = dataResolver(current.parts);
        continue;
      } else if (current is BoundArgsReference) {
        List<Object> nextParts = current.parts;
        if (index < parts.length) {
          nextParts += parts.sublist(index);
        }
        parts = nextParts;
        current = current.arguments;
        index = 0;
        continue;
      } else if (current is BoundStateReference) {
        if (index < parts.length) {
          current = current.constructReference(parts.sublist(index));
          index = parts.length;
        }
        current = stateResolver(current.parts, current.depth);
        continue;
      } else if (current is BoundLoopReference) {
        List<Object> nextParts = current.parts;
        if (index < parts.length) {
          nextParts += parts.sublist(index);
        }
        parts = nextParts;
        current = current.value;
        index = 0;
        continue;
      } else if (current is Switch) {
        final Object key = _resolveFrom(current.input, const <Object>[], stateResolver, dataResolver);
        Object? value = current.outputs[key];
        if (value == null) {
          value = current.outputs[null];
          if (value == null) {
            return missing;
          }
        }
        current = value;
        continue;
      } else if (index >= parts.length) {
        // We've reached the end of the line.
        // We handle some special leaf cases that still need processing before we return.
        if (current is EventHandler) {
          current = EventHandler(current.eventName, _fix(current.eventArguments, stateResolver, dataResolver) as DynamicMap);
        } else if (current is SetStateHandler) {
          current = SetStateHandler(current.stateReference, _fix(current.value, stateResolver, dataResolver));
        }
        // else `current` is nothing special, and we'll just return it below.
        break; // This is where the loop ends.
      } else if (current is DynamicMap) {
        if (parts[index] is! String) {
          return missing;
        }
        if (!current.containsKey(parts[index])) {
          return missing;
        }
        current = current[parts[index]]!;
      } else if (current is DynamicList) {
        if (parts[index] is! int) {
          return missing;
        }
        current = _listLookup(current, parts[index] as int, stateResolver, dataResolver).result ?? missing;
      } else {
        assert(current is! ArgsReference);
        assert(current is! StateReference);
        assert(current is! LoopReference);
        return missing;
      }
      index += 1;
    }
    assert(current is! Reference, 'Unexpected unbound reference (of type ${current.runtimeType}): $current');
    assert(current is! Switch);
    assert(current is! Loop);
    return current;
  }