Value Changed Tag Event Data Quality

[BryanB]

I’ve been chasing this one for a while and haven’t been able to get it figured out. I’m looking to condition a value changed script on a tag event with the value, initial change, and quality and can’t figure out the proper syntax.

Here’s what I have right now:

if currentValue.value == 1 and initialChange == 0:
   # do stuff

What do I need to do to also condition based on data quality? I haven’t been able to successfully use

currentValue.quality == "Good"

or

currentValue.quality == 192

What’s the proper syntax?

Also, is there a good place to look up the members of a data type (for example, the “dataQuality” data type)?

Thanks!

[Duffanator]

if currentValue.quality.isGood():
    *code here*

[BryanB]

I forgot to mention that I’m using 7.9.9. My understanding is the “isGood()” function was introduced in 7.9.11.

[PGriffith]

The isGood() expression function was added in 7.9.11, but the actual quality object returned by QualifiedValue.getQuality() has had an isGood() method for a lot longer. You can also simplify @Duffanator’s a little bit more; if currentValue.quality.good: will do the same thing.

[BryanB]

That worked, thank you. What I ended up with is:

if currentValue.value == 1 and currentValue.quality.good and initialChange == 0:
    # do stuff

[BryanB]

One other related thing - is there a good place to find the addition members of Ignition defined data types? For example, what’s the best way to figure out that “xxx.quality.good” even exists?

[PGriffith]

Some general advice:

User object functions

Unfortunately, at some level (and it’s easy to do, so there’s no real way to tell you exactly when it will be) you “break out” of the expected areas where we’ve documented things and end up in the base Java classes that we’re using internally. Jython automatically wraps these up so they mostly seem like Python objects, so it’s hard to tell exactly when you get there. What I generally recommend, if you’re encountering something unfamiliar and want to see what you can do with it: Start with run…

More specifically:
Printing the type of currentValue.quality (literally, just print type(currentValue.quality) will probably give you something like com.inductiveautomation.ignition.common.sqltags.model.types.DataQuality - the name of the Java class in our codebase. While I'd highly recommend the introspection tools I outline in the above post, you can also just go straight to the reference material (for example: ignition 7.9.5 API) and just look for DataQuality there. You'll see that this class implements the underlying Quality interface, which is where the isGood() method is actually defined.