reference to private data

[vivante]

Hallo guys,

I have try to create a class member where I explore my private data by reference, but I cannot create the reference. Is it possible? can I link the private data cluster in other ways?

thank you in advance,

Vivante

[jgcode]

Hi vivante

A smart man once told me....

You can get a reference Class Control by wiring out is the first index of the Children [] property.

I recommend checking out Francois Normandin's LVClass API too.

Cheers

-JG

[vivante]

Hallo JG,

thank you for your reply.

I've read on Labview context help that Cildren[] property is not available at runt time, my idea is to work on private data using a reference to private data cluster from a member of the class at run-time. I need to compare every single cluster item label with a list of tags and get/set a specific set of values programmatically. My application will use this method to filter some data according to user's selection and he knows only names of cluster's items.

thanks,

Vivante

[Daklu]

I need to compare every single cluster item label with a list of tags and get/set a specific set of values programmatically. My application will use this method to filter some data according to user's selection and he knows only names of cluster's items.

I think it's probably not a good idea for your application to rely on labels if there's another way to accomplish the same thing. Instead of putting each value in a unique control in a cluster, can you use a look-up table? Create a 1d array of strings to hold the names of the data. Create a second 1d array of strings (or ints, variants, etc.) to hold the data value.

[vivante]

Well, Daklu you have understood my idea: I want to use control's labels as keys in my lookup table so I can change private data definition of my class according to my needs (to be correct I must write "to my customer caprice") and I don't have to update manually the array constant you have shown in your example. Sometimes I use this technique to update those panel's controls with same name of my cluster fields (in this case my structure is a simple cluster not a class definition, of course).

Vivante

[Francois Normandin]

I've read on Labview context help that Cildren[] property is not available at runt time, my idea is to work on private data using a reference to private data cluster from a member of the class at run-time.

You will not be able to work on your Private Data at runtime. Creation / Removal of controls and indicators can only be done in the IDE and when the VI is Idle.

If you want to get a reference at runtime, your best chance is with the Open VI reference and wiring "classname.lvclass:privatecontrolname.ctl". AQ mentioned that simple trick is a thread I have not taken time to find again.

But the result is the same, you can't modify data at runtime. I haven't tried if you can even read it at runtime. I'd be really surprised if you could, because there's no reason to be able to get a reference one way and not the other. It's the same reference after all. Let us know if you succeed at runtime.

Well, Daklu you have understood my idea: I want to use control's labels as keys in my lookup table so I can change private data definition of my class according to my needs (to be correct I must write "to my customer caprice") and I don't have to update manually the array constant you have shown in your example. Sometimes I use this technique to update those panel's controls with same name of my cluster fields (in this case my structure is a simple cluster not a class definition, of course).

Vivante

Probably you need to create a private method in your class to support this, instead of going to the Private Class Data directly.

[jgcode]

If you want to get a reference at runtime, your best chance is with the Open VI reference and wiring "classname.lvclass:privatecontrolname.ctl". AQ mentioned that simple trick is a thread I have not taken time to find again.

Here you go.

[Francois Normandin]

Simple answer. The Class Private Data is stripped from its Front Panel in the build process (no way to change this that I know), so we can't get a reference to the specific values on the FP... no FP ref => no data cluster ref => no controls references.

Here you go.

Thanks buddy