Why does Null or UNDEFINED Evaluate to TRUE

RentProperty

Hi Guys, have a look at this:

Why would UNDEFINED or NULL evaluate to true? Is this a bug?
In this specific instance the field ForumPost.Attachment WAS NOT Defined but it Calculates to True WHEN Checking if it is defined?

Kind Regards

Hein

aware_support

If this is a Yes/No field, always compare with "Yes":

If Object.YesNoField <> 'Yes' Then ...

RentProperty

Hi Support, Thanks but I am not comparing with that Attribute. I am trying to set the Yes/No Attribute.

I have a process to Enter an new ForumPost, there is also a Attribute for a document attachment. But what I want to do is in the net rule I want to Check whether the user uploaded a document or not and then Set another Attribute called Has attachment. For some reason the rule that checks whether the Document IS DEFINED evaluates to true even when there were no document loaded.

So my process looks as follow:
RULE 1:
ENTER NEW ForumPost WITH ForumPost.HasAttachment='No'

RULE 2:
IF ForumPost.Attachment IS DEFINED THEN ForumPost.HasAttachment='Yes'

Now it is this condition that is being evaluated in the Screenshot and it Evaluates to true even though there has not been any document Uploaded to the Document Attribute.

Please advise...

Thanks a million!

tford

RULE 2:
IF ForumPost.Attachment IS DEFINED THEN ForumPost.HasAttachment='Yes'

Is this rule part of a process with your ENTER NEW?

If so, I would suggest you just move this rule to being a rule for the BO.

ACDC

Its best to always have an initial value for a Yes/No attribute. Whenever I insert a Yes/No I set the initial value to either 'No' or 'Yes'. This way you never get caught with a 'null' issue. It seems some rules don't understand 'null' on certain attributes, Yes/No is one of them

Also as support suggested use <> 'Yes' or <>'No' instead of IS DEFINED or UNDEFINED. This way if it is null you are guaranteed of rule integrity

BenHayat

ACDC wrote
Its best to always have an initial value for a Yes/No attribute. Whenever I insert a Yes/No I set the initial value to either 'No' or 'Yes'. This way you never get caught with a 'null' issue. It seems some rules don't understand 'null' on certain attributes, Yes/No is one of them

A while back I ran into similar problem with numbers [created thread on that]. Basically, I always initialize numbers with 0 now, because null was returning true, just like you experienced.

RentProperty

Hi Guys! Thank you for the responses.

Please note though... that it is not the Yes/No field that are being evaluated incorrectly. It is the Document Field.

I want to do a check to see if ForumPost.Attachment(Document Attribute) IS DEFINED after the user enters it, and if it IS then I want to set the Yes/No Attribute to 'Yes'.

So my Concern is... Why does the Rule: "IF ForumPost.Attachment(Document) IS DEFINED" Evaluate to true when it is Definitely NOT DEFINED. I.e. I did not load a document into that attribute.

Thanks for your ideas!

Regards

Hein

RentProperty

Hi Guys,

So to illustrate my point better I did another test and took a better screenshot. I Did what TFord suggested and moved the rule to the ForumPost Business Object. Makes No Difference.

In the screenshot below you can see the Attachment is undefined... So theoretically when I click create, the first rule on the object that checks (IF ForumPost.Attachment IS DEFINED) should evaluate to False and NOT Set the HasAttachment attribute to 'Yes'.... but for some reason it Evaluates to True and incorrectly sets the flag:

I have reason to believe this might be a bug?

Kind Regards

Hein

tford

You can use the attached BSV (made with build 1908-) to test Doc and YN fields. To understand what the three attributes in "Values to Watch" are doing, please look at the rules on RegularUser BO.

To test, do the following

Open the BSV & click "change login details" menu item
Click "Save" before you upload any doc and see initial values
Now upload a Doc, click save, and look at values
Now click Doc - to remove the Doc, click save, and look at value

It looks to me that all values are as I would expect. I do not see any issues.

tford

A_Doc_YN_Test_7_1_2015.bsv

A_Doc_YN_Test_7_1_2015.zip

33.29kB

RentProperty

Hi TFord

Thank you! I tried it and Yes this is exactly how I would expect it to work and my implementation is almost exactly like that. However I am using Version 6.0 (Build 2040). Not sure if there is maybe a bug?

I'll quickly build a small bsv in this version and see if i can replicate.

Kindest Regards

Hein

tford

You should be able to import this BSV into the latest build, save it, then test.

RentProperty

Hi TFord

Ok... so I managed to simulate it in a smaller Version 6 BSV (Build 2040).

https://s3-eu-west-1.amazonaws.com/myawareimfiles/TestDocDefined.bsv

1) Create a folder under your C drive called TESTFILES.

2) Import BSV and open in test mode.

3) Create a forum post and do not upload any Document to the Attachment attribute.

4) Notice how the flag is now set to 'Yes' even though there is no Document.

Here are what else I've discovered now... It seems to be a bug associated with when you are using 'FileSystem' for the storage.
If you do it using 'DataBase' the issue does not happen. However If you use FileSystem from the Get Go then you get this issue as then it seems like it does not create the Attachment_DOCDATA column in the database.

Let me know what you think and if I should report this as a bug! Thanks for your time! 🙂

Kind Regards

Hein

tford

You should be able to import this BSV into the latest V6 build, save it, then test.

What happened when you did this?

RentProperty

i Couldn't test it in build 2042 yes As I haven't downloaded that yet.

I tested in 2040 though and your BSV worked perfectly. My Demo one also. But if you start a new BSV and import it and use the FileSystem Storage from the start. (I.e. the first time you put in test mode it is already set to use 'FileSystem') this is how I get the bug to reproduce.

Will however download the latest build later and try it there, but I don't think it will make a difference as that was not one of the bugs that were fixed as far as i know?

Kind Regards

Hein

tford

It sounds like you now have the issue isolated to a file system issue and have a sample BSV to demonstrate the issue to support. That's exactly what support wants with potential bugs.