requestUpdateFor method

void requestUpdateFor(Component component)

Granular update — re-renders and diffs only component's subtree. The browser only sees changes inside the single DOM node that belongs to component. Nothing outside it is touched.

Implementation

void requestUpdateFor(Component component) {
  if (!_mounted) return;

  if (component == rootComponent) {
    _requestRootUpdate();
    return;
  }

  final domNode = _componentNodes[component];
  final prevTree = _componentTrees[component];

  if (domNode == null || prevTree == null) {
    _requestRootUpdate();
    return;
  }

  RenderContext.run(this, () {
    RenderContext.runWithComponent(component, () {
      final result = resolveNode(ComponentRenderNode(component));

      switch (result) {
        case ResolveSuccess(:final tree):
          patch(domNode, prevTree, tree);
          _componentTrees[component] = tree;
          component.onMorph();

        case ResolveFailure(:final error, :final failedComponent):
          // Granular update failure is non-fatal — the component stays in
          // its last valid state. Log and continue.
          // ignore: avoid_print
          print(
            'Pulsar: morph failed for '
            '${failedComponent?.runtimeType ?? component.runtimeType}: '
            '$error',
          );
      }
    });
  });
}