Loop Catches

[datalink]

In our systems we will often use scripts to trap for incorrect or missing data. Around the office we call these 'loop catches' because we use a loop to trap for the problem. They usually look like this:

Loop

If[isEmpty(VariableData)]

Show Custom Dialog ["Variable Data"; "Variable Data must be specified."]

Go to Field[VariableData]

Pause/Resume Script[indefinitely]

End If

Exit Loop If[not IsEmpty(VariableData)]

End Loop

I'm wonder in folks have a more efficient way of doing this. For technical reasons we do need to do these operations in a script, but I bet there other (perhaps better) ways to do this.

[Vaughan]

That looks about right. However if there is a business requirement for the field to contain a value then field level validation can/should also be used. This will manifest itself as an inability for the record to be committed if it fails validation.

I use some field validation, and the loop catch for "modal" data entry into global fields.

[Fitch]

Now that FileMaker 11 gives us the OnObjectValidate trigger, you don't need the loop. Although in this case, OnObjectExit might be a better choice, since if the field starts out blank, and you don't change it, OOV won't trigger whereas OOE will.

If[ IsEmpty( Get ( ActiveFieldContents ) )]

. Show Custom Dialog["Ouch!"]

End If

To keep the user in the field, be sure to put this step at the end:

Exit Script[False]

See this article (be sure to read the comments too):

http://sixfriedrice.com/wp/the-onobjectvalidate-trigger/