Using isblank() to test a value on a form

[Rhett Scott]

I would like to test to see if a field on a form holds a null value. I have a button on a form that performs the record commit operation. When that button is pressed I want to test a numeric field to see if it is set to null (no value entered, not even a zero). I have tried:

Given the field name is draft_day of type numeric and that the form is in ENTER or CHANGE mode

isblank(draft_day.value)
isblank("draft_day.value")

I have also tried

tbl=table.current()
isblank(tbl.draft_day)
isblank("tbl.draft_day")

None of these work and all return an error. I believe this is the correct function but I am using it incorrectly. Does anyone have any ideas for how I could test for a null value.

Thank you

[Tbaker]

Re: Using isblank() to test a value on a form

try

isblank("draft_day")

Tom

[milesjg]

Re: Using isblank() to test a value on a form

Look in the help under "null." Accordingly A5 has no concept of a null. Did you try IsBlank(table->field) or "If field = 0" for numeric.

[gmeredith17]

Re: Using isblank() to test a value on a form

I think you will need to make the field a character type if you want to distinguish between an empty field and 0. Then you can check whether it is empty using draft_day="". You can always use the val() command if you need to use the field for any mathematical operations (assuming that is the reason you have made it a numeric type). I use the following in one of my scripts for a goods in form. It basically adds current stock qty and the qty being booked in to give the total. vstockqty and vrec_qty are both character variables.

vtotal_qty=val(vstockqty)+val(vrec_qty)

You may also want to add some input field integrity by checking that only numbers have been entered into the field using numcheck on the candepart event.

I have the following on one of mine

vnew_rec_qty=parentform:rec_qty.text
num_chk(vnew_rec_qty,.t.)

[Tom Cone Jr]

Re: Using isblank() to test a value on a form

Rhett,

I think you can solve this by checking the text property of the field object displaying draft_day.

if parentform:draft_day.text = "" then
     msgbox("","Field is empty")
     'do further processing
else
    ' do different processing
end if

-- tom

[MikeC]

Re: Using isblank() to test a value on a form

Along with what Tom stated,
To check if a numeric field is "null" or to set a numeric to a null value, use the numeric field's text value to do so.

[gmeredith17]

Re: Using isblank() to test a value on a form

Thanks for the tip. I need to learn joined up thinking. I was checking the text of a field to see if it was a number but for some reason didn't consider using the same method for checking an empty field. Hopefully Rhett now has all he needs to accomplish the task.