Custom error messages on edit form not preventing submit

[Anonymous]

Hi,

I'm having trouble with custom validation checking on an edit form generated from a SharePoint list.  Basically, I have a column Quantity that must be greater than zero.  In the Data Card's error message label, I have:

Coalesce(
    Parent.Error,
    If(
        !IsEmpty(txtQuantity.Text) && !IsBlank(txtQuantity.Text) && Value(txtQuantity.Text)<=0,
        "Quantity must be greater than zero."
    )
)

This correctly displays the error message when viewing the form as I enter negative or positive values in the Quantity field.

The issue is even with an error message displayed the user can still submit the form as the EditForm.Valid property is true.  I've looked at videos on YouTube that don't have anything except SubmitForm(EditForm) in the Save button's OnSelect property and they work (form cannot be submitted).  What am I missing?  This form has a few dozen fields on it so no way I add all those checks to the Save button.  How can I make my custom errors set the form's Valid property to false?  Thanks.

[RandyHayes]

@Anonymous 

On your OnSelect of the save, set the formula to:

If(yourForm.Valid, SubmitForm(yourForm))

Make sure you have logic in the Required property of the DataCard in your form.  That is what dictates what is valid and what is not.

I hope this is helpful for you.

[Anonymous]

This is exactly the problem I'm having.  EditForm.Valid is TRUE even though I enter a Quantity less than zero and the error message is showing.

[RandyHayes]

@Anonymous 

What is the Required property of your DataCard?  And what is the Update property of the Datacard?

[Anonymous]

Required is true, Update is Value(txtQuantity.Text).  The field is always required, but it's an error unless they enter a value greater than zero.

[RandyHayes · Accepted solution]

@Anonymous 

So then there is the issue.  For a form to be Valid, any Required column (Required set to true) must have a value - the value comes from the Update property of the DataCard.

If your Update property is the value of the text input control, and it is zero, it will have a value of 0...which is a value.

Change your Update property to:

With({val: IfError(Value(txtQuantity.Text), 0)},
    If(val > 0, val, Blank())
)

With the above, only values greater than zero will appear in the Update property.  If it is not greater than zero, then the Update property will be blank...and thus, as a required column, will cause the form to not be valid.

[Anonymous]

OK, this looks like it will work in this situation.  What if the field is NOT required, but I still want to do the same check (if there's a value, it must be greater than zero)?

[Anonymous]

The other issue I'm seeing now is the error message doesn't change.  If I enter "0" in the Quantity field it's telling the Quantity is required as opposed to Quantity must be greater than zero.

[RandyHayes]

@Anonymous 

Make the field required then!!

You can alter the Required property on the datacard as you would like.

Normally when you connect the form to the datasource, PowerApps will determine which are required based on what is in your list settings.  But, there is no reason that you cannot alter that property as you need it.

Keeping in mind that in order to have a valid form, ANY datacard that is required MUST have a value on the Update property result.

So, if you want to "invalidate" your form for the purpose of having a message to the user or something to inform them that they have an invalid value, you can work with both the Required and the Update property.

For example, perhaps a column that is not required in the datasource, but you want to have a numeric value greater than 0 be entered in a textinput control.

The Required property would be:  IsError(Value(yourTextInput.Text), 0) = 0

This would set the Required to true if the value is 0.

For the Update property:  If(Self.Required, Blank(), IsError(Value(yourTextInput.Text), 0))

This would set the Update to blank if the Required property is true (which remember, we already put the logic in that property to determine validity, so we can just reference it here) and would output the Value otherwise.  (Note: I still use the IsError statement as otherwise PowerApps can give false errors at design time that are just annoying)

One other thing I would do for a "standard form" that has the visual "required" asterisk label in it, is to get rid of it or disable it so it does not appear based on the above.

[bradt30h]

Is the formula correct? It doesn't work in my app.