Validating required fields when datacards are conditionally hidden

[OneWinPlease]

I have a service ticket app, and the first field is Request Type. Based on the type chosen, some other fields will not be visible. But when they ARE visible, I want them to be required. I'm not having any luck coming up with a solution. So far I haven't gotten the IfBlank formula to work, because it seems to depend on the Submit button's display mode, and I can't touch that button because I need it to be active for all Request Types. It's a 2 screen app by the way. Any ideas? Thanks.

[Amik]

@OneWinPlease - I would leverage the whatever logic your using to control the Visible property of the DataCards to also apply to the Required property.

For example, I would use the below on the Visible property of the DataCards:

Len('Your Request Type ComboBox'.Selected.'Column') > 0

And then use the below on the Required property:

Self.Visible

And then use the below on the DisplayMode property of the Submit Button:

If(
   'Your Form'.Valid,
    DisplayMode.Edit,
    DisplayMode.Disabled
)

[WarrenBelz]

Hi @OneWinPlease ,

You could simply have 

Self.Visible

in the Required property of the Data cars

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[OneWinPlease]

@WarrenBelz I will try this, it seems to work with one card, will do with others to be sure.  I don't find anything online to explain this formula. Could you share a little about why/how it works?

[OneWinPlease]

@Amik  thank you.  I will try this. 

[Amik]

@OneWinPlease - Len is a function. The output of a control which returns no characters has a Len of 0. The above is the equivalent of using:

!IsBlank('Your Request Type ComboBox'.Selected.'Column')

Or:

Not(IsBlank('Your Request Type ComboBox'.Selected.'Column'))

[OneWinPlease]

Thank you. For whatever reasons, my controls/forms are complicated enough for this to not quite work for me. Instead I want to disable the display mode property of the Next button (goes from screen 1 to screen 2).  However, the app is not accepting my formula of 

If(IsBlank(DataCardValue6.Text), DisplayMode.Disabled, Edit)

DataCardValue6 is the text input box I want to be required in order to move to the next screen.  The error says  "The function If has some invalid arguments."  THe same happens when I remove If and just have IsBlank. Any thoughts?

[Amik]

@OneWinPlease - I cannot comment on the error because I do not know your app and whatever customisations/modifications you made to that EditForm. I would simply repeat the same advice posted earlier.

To understand the basic concept:

1. Create a New Screen.

2. Add an EditForm control into this Screen.

3. Add the relevant DataCards, including the DataCard for Request Type.

3. For each DataCard which needs to be visible based on the selected request type, I would use the below on the Visible property:

'Your Request Type ComboBox'.Selected.'Column' = "Some Request"

If there is more than one request type you want to apply the logic for, use:

'Your Request Type Combobox'.Selected.'Column' in [
    "Choice 1",
    "Choice 2",
    "Choice 3"
]
//The above code assumes you're not using Dataverse and the combobox is not set to allow multiple selections

4. For each DataCard you want to set as required, use the below on the Required property:

Self.Visible

5. On the DisplayMode property of the Next button, I would use:

If(
   'Your Form'.Valid,
    DisplayMode.Edit,
    DisplayMode.Disabled
)

[OneWinPlease]

@Amik Thank you. I had already known how to hide datacards based on request type. The problem is making these text input fields required when they are not hidden. Their required properties are marked as true, but this doesn't stop users from leaving them blank and proceeding to the next screen. So I am trying to use the If(IsBlank formula and it's throwing that error. I think it may be because I have set variables onStart, but not sure. I don't yet understand how variables work, and how they might affect formulas elsewhere in the app.

Regarding form validation, unfortunately my form doesn't have a Valid property available. I'm unsure why. It's not in the advanced properties. 

[Amik]

@OneWinPlease - The reason I provided you with the example above was to help you understand the basic concept so you can apply it to your scenario. The EditForm Valid property is accessed using formulas (like the one I provided above).

I have nothing further to add here.