Xbasic

FIELD.IS_BLANK Function

Syntax

Blank_Flag as L = Is_Blank()

Description

Returns TRUE if the field is blank.

Discussion

The .IS_BLANK() method returns TRUE (.T.) if the specified field is blank (i.e., has no value). The field can be specified either by using the field object pointer, or by using ..IS_BLANK()with a table object pointer and a field name. If the field has an assigned value (including 0), this method returns FALSE (.F.). For example, a table of average weekly temperatures can have some weeks during which temperatures were not taken. To find an off week, you search for blank temperature fields using the .IS_BLANK() method. You do not search for zero because zero can actually be a valid average temperature. All fields are blank before data is entered into them.

Example 

Check if the lastname field is blank using a field object pointer.

dim tbl as P
dim fld as P
tbl = tbl.current()
'Get a field pointer to the lastname field
fld = tbl.lastname.this
flag = fld.is_blank()
if flag then
    ui_msg_box("Lastname field is blank","")
else
    ui_msg_box("Lastname field is not blank","")
end if

Check if the lastname field is blank using a table object pointer and the field name.

dim tbl as P
tbl = tbl.current()
flag = tbl.lastname.IS_blank()
if flag then
    ui_msg_box("Lastname field is blank","")
else
    ui_msg_box("Lastname field is not blank","")
end if

See Also