Flatten To String: Convert 7.x Data

[Donald]

Hello,

I noticed that the Flatten To String function in the attached LV711 VI does not stay in the "Convert 7.x data" format mode. Other VIs in my project (also with variant data type input) stay in the LV7 format when loaded with labVIEW 8.20. I guess this is a minor bug which is not yet reported.

If nobody can explain why this VI behaves different I will send a bug report to NI.

Best regards,

Donald

Download File:post-2015-1168597339.vi

[Mellroth]

I noticed that the Flatten To String function in the attached LV711 VI does not stay in the "Convert 7.x data" format mode.

Hi,

the reason for this is that this VI doesn't use the type-descriptor output (your other VIs probably do), so there is no need to use the LV7 version.

See attached VI.

Download File:post-5958-1168604159.vi

/J

[Donald]

Hello JFM,

Thanks for the fast reply. You are right I just tested it, the connection of type descriptor solves the problem. Didn't notice this difference.

Note: The flattened string content is (as expected) not the same when set to 'lv7 format', I know that I should not parse this content myself but rather use the unflatten function :-)

Mystery solved and NOT a bug.

Best Regards,

Donald

[robijn]

Mystery solved and NOT a bug.

Why not ? Shouldn't the 7.11 just work if loaded in LV8.20 ? Or does it work ?

Joris

[Donald]

Joris,

For me it was a bug because the behavior of enabling the 'LV7 format' mode or not didn't seem consistent.

Because the content of the string should not be used without using the type descriptor my first thought was: it is not a bug because one should always wire the type descriptor output. However I can think of constructions where there is no need in wiring the type descriptor everywhere in the application I just looked around in an existing application I'm working on here in Beerse and yes I identified a construction where it will go wrong when converted to LV8.2.

I will send the problem as 'odd' behavior to NI support.

Best regards,

Donald

[Rolf Kalbermatter]

Joris,

For me it was a bug because the behavior of enabling the 'LV7 format' mode or not didn't seem consistent.

Because the content of the string should not be used without using the type descriptor my first thought was: it is not a bug because one should always wire the type descriptor output. However I can think of constructions where there is no need in wiring the type descriptor everywhere in the application I just looked around in an existing application I'm working on here in Beerse and yes I identified a construction where it will go wrong when converted to LV8.2.

I will send the problem as 'odd' behavior to NI support.

It is definitely a bug. Since the Flattened data output string is not the same this will cause problems. There are many cases where Flatten/Unflatten are just used to get the data into a stream format and back and the context alone is enough to determine what data has been flattened so that parsing the typedescriptor, which until a few versions of LabVIEW was documented but no official VIs for this parsing were available, was absolutely unnecessary.

And someone at NI obviously thought that the typedescriptor was superfluos too (I definitely don't agree but have no influence on that) otherwise they wouldn't have removed it in LabVIEW 8, would they.

Rolf Kalbermatter