pass object as reference

[j3r3mi]

Hiw can i pass a LV object as a reference?

[PeterFoerster]

What exactly do you mean?

You can create references as seen in the picture...

[j3r3mi]

Sorry i didn't have a proper question. I have a LV class - Thread. Which has a VI that runs ascyn. LV is baased on data flow, thus most things are pass by values. However i wanted to hold values for the Object created in the VI therefore it has to be pass by reference.

Whats the generic lass for LV object?

[satish_21]

You can use a global variable in that case. Check out the link below.

https://www.ni.com/docs/en-US/bundle/labview-api-ref/page/functions/global-variable.html

Satish

[j3r3mi]

Well, global would solve the problem not i won't do it as it defeats the purpose of OO, having data encapsulated. Anyway thanks!

[satish_21]

You can still create references from objects. I was able to do it, in the usual way ( Right click object -> Create -> Reference).

Once you drop the class in block diagram, did you select right - click and  'Change to control' ?

Satish

[Ben]

Search this site for "Singlton".

There are a couple of ways of achieving a Singlton in LV. Early versions used a single element queue to hold the data so that only the thread that has the lock on the queue can access it.

An updated version uses a DVR (Data Value Refence) to hold the instance of the class.

If you are developing an Active Object there is supposedly ( I have not read it yet) an Actor pattern recently included in LV.

I hope that helps,

Ben