The getter 'iterator' was called on null about flare-flutter

[umberto-sonnino]

Hey @ricsmania thanks so much for the PR, this is another great catch!

We reviewed it, and it happens quite often, in complex rigs, that people use empty nodes as targets. It would be beneficial to save the extra memory and check for the nullness of the item before calling the iterator:

if(children != null) {
  for (ActorNode in children) {
    [...]
  }
}

Feel free to update your PR with this, and we'll merge it!

[ricsmania]

I created a PR with a suggested solution.

[luigi-rosso]

Thanks for your continued contributions @ricsmania!

[ricsmania]

@umberto-sonnino I updated the PR with your suggestion. I also saw another unchecked part here on actor_node.dart:

bool all(NodeWalkCallback cb) {
    if (cb(this) == false) {
      return false;
    }

    // here
    for (ActorNode child in _children) {
      if (cb(child) == false) {
        return false;
      }

      child.eachChildRecursive(cb);
    }

    return true;
  }

I didn't get any errors there, so I left it alone, but if you think that should also be checked I can add it too.

@luigi-rosso no problem, I'm happy to help!

[vidu171]

Hey, I came across this error while I was making an app, is there any solution that i can implement?, Like I tried to delete all the empty nodes from my flare file. But it did not do anything

[vidu171]

@ricsmania , thanks a lot your solution worked I would also like to point out that in the flare.dart file there is a similar problem and I made the following changes

if (children != null) {
      for (ActorNode node in children) {
        FlutterPath flutterPath = node as FlutterPath;
        if (flutterPath != null) {
          Mat2D transform = (node as ActorBasePath).pathTransform;
          _path.addPath(flutterPath.path, ui.Offset.zero,
              matrix4: transform == null ? null : transform.mat4);
        }
      }
    }

which is now working completely fine. I will make a PR for it soon.