Darren's Occasional Nugget 03/25/2014

[Darren]

I attended the European CLA Summit last week (my first trip outside the USA!). At the summit I gave a presentation that discussed, among other things, the VariantDataType VIs. Among the myriad use cases for these VIs is checking a variant to see if it matches a particular type. For example, we have a VI that ships with LabVIEW that will assess whether or not a variant is an error cluster (for reference, this VI lives in vi.lib\addons\analyzer\_analyzerutils.llb\VIAnUtil Check Type If ErrClust.vi):

In this VI, we check the variant to see (1) if it is a cluster, (2) if it has three elements, and (3) if those elements are Boolean, I32, and String (in order). I have often recommended this approach for type checking over a simple Variant To Data function call, since Variant To Data will attempt the conversion, even if the types don't match exactly:

Another great use case for these VIs is programmatically retrieving, at runtime, the names of enum entries as a string array:

The VariantDataType VIs are great for data type parsing, and these are just two of many use cases that demonstrate the power of this undocumented API. Have you encountered a novel use for the VariantDataType VIs in your applications?

[LabBEAN]

Enum to string array, nice.  Is there a slide deck that you are able to post?

[Darren]

Yup, you can get the presentation here.

[InfiniteNothing]

Can we bring some of these functions into the "officially supported" set?

http://forums.ni.com/t5/LabVIEW/Make-VariantDataType-functions-officially-supported/td-p/2792204

I hope you don't mind I borrowed one of your images

[juncaofish]

Hi, I used to download MGI toolkit from VIPM and it has a palette for all the variant type stuff.

[ohiofudu]

Darren,

that  was a great presentation at the summit in CERN.

[Yamaeda]

Variants are indeed very nice and powerful, i've made a general ini-file writer/reader through that.

It begs the question: Why are the functions hidden? The Variant palette needs fleshing out, if not in the direct palette, then in a "advanced" subpalette.

/Y

[Hooovahh]

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@juncaofish wrote:

Hi, I used to download MGI toolkit from VIPM and it has a palette for all the variant type stuff.

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Same with OpenG which also has a Enum to String or String to Enum.  Still I'm in favor of native support over 3rd party when functionality is the same.

[JÞB]

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@Yamaeda wrote:

Variants are indeed very nice and powerful, i've made a general ini-file writer/reader through that.

It begs the question: Why are the functions hidden? The Variant palette needs fleshing out, if not in the direct palette, then in a "advanced" subpalette.

/Y

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1. Tools>>Advanced>>Edit Palatte set...(drink Coffee)
2. Right click an open palatte position Insert>>Subpalatte:  
3. Check Link to a directory    
4. Browse to <LabVIEW> \vi.lib\Utility\VariantDataType
5. Select Save
6. select Continue

Whoomp! There it is:

Cross-Posted to uNuggets Thread since this comes up WAY TOO OFTEN.

[Hooovahh]

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@JÞB wrote:

1. Tools>>Advanced>>Edit Palatte set...(drink Coffee)
2. Right click an open palatte position Insert>>Subpalatte:  
3. Check Link to a directory    
4. Browse to <LabVIEW> \vi.lib\Utility\VariantDataType
5. Select Save
6. select Continue

Whoomp! There it is:

Cross-Posted to uNuggets Thread since this comes up WAY TOO OFTEN.

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Not needed just install the package in the Package Network made by NI called Hidden Gems in vi.lib as mentioned at the end of the slides posted by Darren.

Edit:  Thank you by the way for making this a package.  I already have a vi.lib package with many of the things you mentioned in your slides but not all so this is easier.