[<<Previous Entry]
[^^Up^^]
[Next Entry>>]
[Menu]
[About The Guide]
VS_Filt() Interactively build a filter
Description:
VS_Filt() provides a non-screen destructive user interface to allow
the user to select a list of fields, logical connectives and
comparison constants from pop-up lightbar windows.
Syntax:
c_Filter = VS_Filt()
Pass:
Nothing
Return:
c_Filter is a character expresstion that will contain the desired
filter (blank if the user specified "no filter").
Notes:
Example:
c_Filter = VS_FILT()
IF EMPTY(c_Filter)
c_Filter = ".T."
ENDIF
DO WHILE &c_Filter
.
.
.
SKIP
ENDDO
Usage:
VS_Filt() is designed to provide the uninitiated user with an easy
interface to "filter" specification building. It is database
independent and limits the choices available in the light bar menus to
those that are applicable to the variable type selected. As the user
selects fields, relational operators and comparison constants, the
string VS_Filt() builds is also displayed on the screen.
VS_Filt() alone is not a powerful function, but when combined with the
macro substitution capabilities of Clipper, the two become very
powerful indeed. The string returned by VS_Filt() is suitable for
macro subsitution in the SET FILTER TO command as well as any FOR
clause in any Clipper command supporting that clause (such as REPORT,
SORT, COPY, LIST, DO WHILE, etc.)
See Also:
This page created by ng2html v1.05, the Norton guide to HTML conversion utility.
Written by Dave Pearson