Enum List Validation

[weowens1984]

Does anyone know how to perform data validation on a Enum List so that the user is required to pick ONE certain item in the list, but could also select that required option along with others.

For example, If I had the following list but wanted to require “Cat” was selected.

1. Cat
2. Dog
3. Bird

Accepted: Cat
Accepted: Cat, Dog, Bird
Not Accepted: Dog, Bird

Any help with this would be appreciated. Thanks!

[Marc_Dillon]

IN( "Cat" , [_THIS] )

help.appsheet.com

IN()

Is item in list?

[weowens1984]

So simple yet it was making me bang my head against the wall. Thank you so much Marc!

[SkrOYC]

You could use this awesome post by Matt showing how to make custom messages when the validation rule says it can’t be save

How To Show a Custom Valid If Error Message Tips & Tricks 💡

You’ve been working long and hard to get your Valid If formula correct, and finally it’s doing what it’s supposed to - preventing duplicates, wrong info, bad dates, etc. from being entered by your users. But now you want to go a step further and provide the user with some info about WHY the data they entered is invalid. This is where the “Invalid value error” field comes into play. [Shared with CloudApp] Utilizing this features is extremely easy, due to the fact that most the hard work has …

I know it’s kinda advance but it’s a good resourse of improvement/knowledge

[weowens1984]

At first glance this seemed like the obvious answer. After trying to implement it makes it so that field does not appear at all in my form. Any other ideas?

[Marc_Dillon · Accepted solution]

weowens1984:

After trying to implement it makes it so that field does not appear at all in my form

Interesting. I did not expect this particular issue in this situation. A better solution would be:

AND( TRUE, IN( "Cat" , [_THIS] ) )

If you use CONTAINS, that would also allow someone so select, say “Bobcat”, without selecting “Cat” as well.

[weowens1984]

I definitely overlooked the fact that CONTAINS could potentially create some problems. I tried your most recent post and it worked well and has been marked as the solution.

Do you know why adding the AND/TRUE will allow it to work? It seems redundant, as the logic creates the same end result.

[Marc_Dillon]

I was kind of hoping you weren’t going to ask, lol.

Its intention is to avoid a certain automatic behavior within Appsheet. But that is not for this exact situation. So really I’m not sure exactly why its needed here. I think it may just be some small edge-case glitch.

Consider the situation where you have a single-value column (Text,Enum,Number,etc), and you want to validate the input against a List somewhere, but you do not want to show a dropdown. You’d initially think to use a simple IN( [_THIS] , list-to-check ). However, Appsheet likes to automatically create dropdown lists when it sees a simple IN() expression in the valid_if, so you’d get a dropdown. The common approach there is to basically create a logically-equivalent expression, but so it’s not just a simple IN(). Both OR( FALSE , IN() ) and AND( TRUE , IN() ) accomplish the same thing.

So, even though your situation is quite different, since it’s still a simple IN() in the valid_if, I figured the same solution would work.

[weowens1984]

Haha! Well thank you for taking the time to explain it to me! That makes perfect sense. Hopefully in the future I will now be able to figure it out on my own so I can keep the ‘unwanted questions’ to myself! lol

Thanks again!

[weowens1984]

I tried a slightly different version of your solution using ‘Contains’ instead of ‘In’ and it works perfectly now.

Contains([_THIS],“Cat”)

Thanks again!