Hello all, I have an expression rule which looks up (via query) and then re

Have you tried the plugin "Set CDT properties"? I am not shure but it might match your needs.

I'm primarily using a cloud installation, so it's not easy for me to install new plugins for testing purposes, but i'll look into it.

You will have to use two nodes for this operation, one to save the pv from query rule, and the other one that overwrites one of the attributes.

@Mike: that's what I usually do, however in this case I am using a single expression rule to return a CDT which is used to pre-populate about 40 fields on a single user input task form (each field has slightly different parameters passed into the same rule to get different results), and there's a corner case where I would really like to override the value of the returned CDT to Zero... yep, a head-scratcher...

If you are on 7.2, you could try using the with() (forum.appian.com/.../Evaluation_Functions function and cast the result into your CDT. I cannot say I have done this before but theoretically you should make it work in a single expression.

Thanks - I've started getting familiar with the with() function, but I'm less sure on how to manually cast - any hints?

Hi Mike,

I think you can use load() and dictionary syntax to accomplish this. Try something like:

load(
          mycdt:<expression to initialize mycdt>,
          if(
                    not(<corner case expression>),
                    local!mycdt,
                    {field1:local!mycdt.field1, field2:local!mycdt.field2, field3:0}
          )
)

It will be a bit tedious to type out all 40 fields, but this should get your desired result in 1 expression.

A minor adjustment to Andrew's response. Firstly, in this case it wouldn't make a difference if you use with() or load() - forum.appian.com/.../Evaluation_Functions. What I would do is with( mycdt: <expression to initialize>, if(not(<corner case exp>), mycdt, type!CDT_NAME(field1: mycdt.field1, field2:mycdt.field2 ..... ) ) You need the type! constructor to cast your results to the CDT type. If you have never used a type constructor, I would recommend going to the expression editor and seeing what happens when you write type!CDT_Name(). Then play around with that...do type!CDT_Name(field1: "test") etc. Hope this helps.

@Andrew and Revat - thanks a bunch, your combined suggestions helped me do what i needed. To clarify, I was calling this one expression rule in about 30 different places, but luckily i didn't need to modify those at all, just the rule itself, so it worked out pretty well.

Revat, if I can call you in for one further piece of advice here: I'm using the type! constructor (successfully) as you recommended, with the following issue: the expression rule fully evaluates the CDT with the URL of our dev environment, any time the rule is saved. The rule is now generating an error when we try to import it into our test environment, and I believe this is the reason for the error (mismatched URLs). I have tried stripping out the URL but it always reverts back to how it was. Is there anything I can do to force it to save ONLY by the name of the CDT (since the same CDT will be imported to the other environment anyway)? Otherwise this functionality isn't of much use to me, since it isn't cooperating with the environment port.