[Bug] fromJson not converting empty strings to null as described

RE: [Bug] fromJson not converting empty strings to null as described

Arthur Lyrio — Wed, 05 May 2021 15:32:23 GMT

Great solution, I prefer using split to a Text path instead of using an array.

RE: [Bug] fromJson not converting empty strings to null as described

Arthur Lyrio — Wed, 05 May 2021 15:23:36 GMT

Yes, it's a nice approach.

We usually just learn the index function first and as the property does a part of the same job the index does we usually forget about it and use index for everything.

But for readability, it is much better as it speaks out what it is doing there on the code, getting a property.

In fact, seems that index is the one that does more stuff "than it should do" looking only by its name.
Even if some languages have named indexes already, don't know maybe I am being a little old school here hahahahah

But, thanks for the tip Mike Schmitt

RE: [Bug] fromJson not converting empty strings to null as described

Mike Schmitt — Wed, 05 May 2021 14:17:58 GMT

On my normal soapbox: index() and property() have allegedly identical functionality, but as usual i must insist that you consider using them for their namesake purposes. That is to say, if you're getting an index (i.e. a position in an array), use index(). If you're getting a property (i.e. a dot property member of a CDT or dictionary), use property(). When code gets more complex this dramatically increases readability later on. There are zero reasons not to do this.

RE: [Bug] fromJson not converting empty strings to null as described

Stefan Helzle — Wed, 05 May 2021 09:44:46 GMT

Do this

if(
  isnull(ri!path),
  ri!data,
  reduce(
    index(_,_,ri!default),
    ri!data,
    ri!path
  )
)

Where path is a list of a mix of field names and indexes.

RE: [Bug] fromJson not converting empty strings to null as described

Arthur Lyrio — Wed, 05 May 2021 09:41:18 GMT

Nice, thanks , found its documentation here didn't know about it 🙂
Thanks

RE: [Bug] fromJson not converting empty strings to null as described

Arthur Lyrio — Wed, 05 May 2021 09:38:46 GMT

Yes, it's safer, but is verbose as hell.

Of course safety is more important, but who did this tried to access the fifth property on a chain, like this:

base.porpertyOne.propertyTwo.propertyThree.propertyFour.propertyFive

We fixed with something like this:

index(
  index(
    index(
      index(
        index(
          base,
          "propertyOne",
          null
        ),
        "propertyTwo",
        null
      ),
      "propertyThree",
      null
    ),
    "propertyFour",
    null
  ),
  "propertyFive",
  null
)

But the problem here is not the amount of code to solve this, but the divergence between what was documented to its actual behavior.

Question/Suggestion:
Can't Appian just ignore all of those properties ahead of the variables if the variable is not of a dictionary/CDT type as it "does" to null, for example ?

RE: [Bug] fromJson not converting empty strings to null as described

Stefan Helzle — Wed, 05 May 2021 09:37:11 GMT

error() is a supported function while try() is not.

RE: [Bug] fromJson not converting empty strings to null as described

Arthur Lyrio — Wed, 05 May 2021 09:11:32 GMT

Mike Schmitt
Yeap, we fixed using the index function to get the value if it is present, thanks for the suggestion.

But isn't error() or even try() undocumented ?

RE: [Bug] fromJson not converting empty strings to null as described

Peter Lewis — Tue, 04 May 2021 17:48:28 GMT

Agreed with Mike - it's always better to use a function that allows for null checking like property() or index(). Also one thing to keep in mind: "" is also considered null. For instance, if you try

"" = null

it should return true. However, the problem is that "" is of type text, while null doesn't have a type. A text doesn't allow you to index fields out of it, while a field that is any type would allow that.

RE: [Bug] fromJson not converting empty strings to null as described

Mike Schmitt — Tue, 04 May 2021 17:26:51 GMT

As an aside, I always recommend using the property() function when accessing a CDT or dictionary property from an object when you're not sure whether it'll actually have that property. This allows you to sidestep even needing error messages. If you really require a system error, you could look into using error() depending on whatever result you're returned from the property() function.