Dynamic Event Registration Using Objects

[Norm Kirchner]

I have about 25 dynamic events being registered to an event structure which look like this

http://forums.lavag.org/index.php?act=attach&type=post&id=5317

If I were to do a registration of only 1 item and that items object class was LVObject,

When I fired the event and passed a child class to the event, would the object wire (of LVObject class)returned within the event structure properly dynamic dispatch to the appropritate class?

I know if you cast a child class to a parent, the childs data is retained, but will it dispatch to the child method rather than the parent?

-Norm

http://forums.lavag.org/index.php?act=attach&type=post&id=5318

[Jim Kring]

QUOTE(njkirchner @ Mar 27 2007, 02:26 PM)

I have about 25 dynamic events being registered to an event structure which look like this

If I were to do a registration of only 1 item and that items object class was LVObject,

When I fired the event and passed a child class to the event, would the object wire (of LVObject class)returned within the event structure properly dynamic dispatch to the appropritate class?

I know if you cast a child class to a parent, the childs data is retained, but will it dispatch to the child method rather than the parent?

-Norm

First off, just as an FYI, you can pass a cluster (or clusters of clusters) into the Register for Events node and the events will be available as a nested tree. You don't need to pass each user event reference into the Register for Events node.

Second, yes, the dispatch should work fine.

[Norm Kirchner]

QUOTE(Jim Kring @ Mar 27 2007, 05:32 PM)

First off, just as an FYI, you can pass a cluster (or clusters of clusters) into the Register for Events node and the events will be available as a nested tree. You don't need to pass each user event reference into the Register for Events node.

The problem with this is you still have a bundle node w/ 25 elements.

That aside, thanks for confirming my question.

-Norm

[Jim Kring]

QUOTE(njkirchner @ Mar 27 2007, 03:37 PM)

The problem with this is you still have a bundle node w/ 25 elements.

That aside, thanks for confirming my question.

-Norm

> The problem with this is you still have a bundle node w/ 25 elements.

Not if your events are already in the same cluster. I just wasn't sure if you knew this. I've seen people unbundle events and wire each event, seperately, into the Register for Events node -- so, it's worth mentioning. I'll be writing a blog article about this, soon.

[Aristos Queue]

QUOTE(njkirchner @ Mar 27 2007, 04:26 PM)

I know if you cast a child class to a parent, the childs data is retained, but will it dispatch to the child method rather than the parent?

Yes.

Data traveling on a class wire will always dispatch to the class of the data, not the class of the wire. That is the very definition of dynamic dispatching. The classic demo:

Drop a constant of Parent and a constant of a Child. Drop a Build Array. Wire both constants to the build array. You get an array of Parent. Wire that to the border of a For Loop (indexing tunnel) and wire the inside to a dynamic dispatch subVI. Run the VI and watch as the first iteration calls the Parent version and the second iteration calls the Child version.