topic Re: Add new class to project programmaticly in LabVIEW

Add new class to project programmaticly

WireJunky — Mon, 08 Feb 2010 06:13:36 GMT

I'm trying to streamline my development using classes. I have found a way to add folders and such to a project programmaticly, but no success with how to add a new class. My goal is to make a utility that can generate a class skeleton for me to modify as needed.

Re: Add new class to project programmaticly

Robbob — Tue, 15 Jul 2025 19:18:08 GMT

Wirejunky,

LabVIEW has built-in object oriented programming capability. The links at Can I Use Object-Oriented Programming in LabVIEW? give a lot of great information on how to use it!

Re: Add new class to project programmaticly

Corny — Tue, 09 Feb 2010 20:02:18 GMT

just created this fast (prob. better ways to do it). Here I also created the class itself.

Just a fast example. You can play with lots of more in there. Here I also created the class itself. Its fully possible to add a class to your project 🙂 With the create code at the beginning youve lots of class options to use.

Re: Add new class to project programmaticly

Robbob — Tue, 09 Feb 2010 20:23:57 GMT

Sorry, missed the part on doing this programatically 🙂 Good catch, corny!

Message Edited by Robbob on 02-09-2010 02:23 PM

Re: Add new class to project programmaticly

WireJunky — Wed, 10 Feb 2010 14:37:25 GMT

Thanks Corny for your example! Learnt something new today . Now if only you didn't need to save the class first to disk... I am thinking of how you create classes in the project manager, where creating and adding the class to the project does not create a class file on disk. I am going to play around a bit and see if I cant get that type of behavior.

Re: Add new class to project programmaticly

Ben — Wed, 10 Feb 2010 14:45:01 GMT

Corny wrote:
just created this fast (prob. better ways to do it). Here I also created the class itself.

...

Just a fast example. You can play with lots of more in there. Here I also created the class itself. Its fully possible to add a class to your project 🙂 With the create code at the beginning youve lots of class options to use.

This reminds me of an expression we used when I graduated from my Navy "A School".

"Six months ago I didn't know how to spell Technician. Now I is one."

Nice post,

Ben

Re: Add new class to project programmaticly

Hummer1 — Wed, 10 Feb 2010 15:50:51 GMT

Ben,

Well, Navy...that explains a lot...

Hummer1

learning every day too.

Re: Add new class to project programmaticly

Corny — Wed, 10 Feb 2010 16:10:08 GMT

WireJunky wrote:
Thanks Corny for your example! Learnt something new today . Now if only you didn't need to save the class first to disk... I am thinking of how you create classes in the project manager, where creating and adding the class to the project does not create a class file on disk. I am going to play around a bit and see if I cant get that type of behavior.

Ive also tried to not save it, and add the reference to the project by entering the type (string) "class" or "lvclass" (I think this is what you tried?, for folders you would use the string name "folder"), but then, it popped up as an unkown object in the project manager.

Perhaps if you think the class as a file (it is actually a file), and a folder in the project as a "virtual folder (it doesnt need to exist on HDD)" than perhaps it makes sense?!? (just something that popped to my mind) 🙂

Re: Add new class to project programmaticly

Corny — Wed, 10 Feb 2010 16:27:43 GMT

ops didnt read your post entirely.. my bad. "fast reader" litirally (how the heck is that spelled). If its possible to add classes that are in memory and not HDD to project, inform if you find out (I didnt got it to work) 🙂

Re: Add new class to project programmaticly

WireJunky — Wed, 10 Feb 2010 18:12:39 GMT

K, I played around abit and I got this to work. By using the AddItemFromMemory method and supplying it with the newly created class name I was able to add the class to the project without first saving the class to disk.

This creates a new class in the project manager....

Thanks Corny for your help so far!.... now the cherry on top would be to programmaticly set the access scope of the internal virtual folder of the newly created class.

Re: Add new class to project programmaticly

WireJunky — Wed, 10 Feb 2010 18:32:23 GMT

Hey, I am getting the hang of this... thought it would be alot harder, but five minutes later I got it working. The trick is to set the access scope using a method from LVClassLibrary.

This then creates the following..

Again, thanks for all the help

Re: Add new class to project programmaticly

Ben — Wed, 10 Feb 2010 18:38:24 GMT

Hi WireJunky,

I think you have license to mark your reply as the solution (unless you want to mark corny's )

Ben

Re: Add new class to project programmaticly

Corny — Wed, 10 Feb 2010 19:04:44 GMT

cool. Using the name of the object in memory to add it to the project! didnt know that was possible - learned something new

Perhaps even the LVClassLibrary(Name) prop. node can be avoided since you already know the name? (will try this, and ofcourse see what will happen with more items with the same name (if thats a identifier, it should give an error?)

Re: Add new class to project programmaticly

WireJunky — Wed, 10 Feb 2010 19:14:32 GMT

Hi corny,

I just put the class name property in there because I was lazy ,

you need to add the item using its full name -for the newly created class this would be "Test.lvclass"

Re: Add new class to project programmaticly

Corny — Wed, 10 Feb 2010 19:21:39 GMT

hehe, thanks. And to inform, it does give out an error:

Error 43 occurred at Invoke Node in Untitled 1

Possible reason(s):

LabVIEW: Operation cancelled by user.

Method Name: LabVIEW Class:Create

with more than one classes with the same name. (dont ask me why its error 43 tho). Edit: The error only happends if one of the objects properties have been read, or written to, before creating a new one with the same name.

Message Edited by Corny on 02-10-2010 08:21 PM

Re: Add new class to project programmaticly

WireJunky — Wed, 10 Feb 2010 19:31:59 GMT

Trying to think if there exists a situation where you would want or would have two classes with the same name...

cant think of any, but I could be wrong. Now I wonder if it isn't possible to create some override vi's programmaticly.

The first step would be setting the parent of the newly created class and then... somehow create those override vis

Re: Add new class to project programmaticly

Corny — Wed, 10 Feb 2010 19:43:54 GMT

hehe, no there really is no point in doing that. but what the heck, just wanted to see if it happends (In case youll get a typ'o (or wire'o) its good to know). Love trying out stupid stuff 🙂

Re: Add new class to project programmaticly

WireJunky — Wed, 10 Feb 2010 20:14:21 GMT

Think Ive hit the end of the road with this endeavor, there are no methods or properties that set the parent of the created class.

There is a property to get the parent, but not to set it. Anyway, was worth a try.... - hope someone can prove me wrong.

At least Ill be able now to create a empty class skeleton with some commonly used virtual folders to organize things nicely