Return a set-get code block for a field in a given work area

     FIELDWBLOCK(<cFieldName>, <nWorkArea>)
        --> bFieldWBlock


     <cFieldName> is the name of the field specified as a character

     <nWorkArea> is the work area number where the field resides
     specified as a numeric value.


     FIELDWBLOCK() returns a code block that, when evaluated, sets (assigns)
     or gets (retrieves) the value of <cFieldName> in the work area
     designated by <nWorkArea>.  If <cFieldName> does not exist in the
     specified work area, FIELDWBLOCK() returns an empty block.


     FIELDWBLOCK() is a database function that builds a code block.  When
     evaluated with the EVAL() function, the code block first selects the
     designated <nWorkArea>.  If an argument was passed, the code block then
     assigns the value of the argument to <cFieldName>.  If no argument was
     passed, the code block retrieves the value of <cFieldName>.  The
     original work area is then reselected before the code block returns

     Note that the specified field variable may not exist when the code block
     is created but must exist before the code block is executed.


     .  FIELDWBLOCK() is similar to FIELDBLOCK(), except that
        FIELDBLOCK() incorporates a fixed work area into the set-get block.


     .  This example compares FIELDWBLOCK() to a code block created
        using the macro operator.  Note that using FIELDWBLOCK() avoids the
        speed and size overhead of the macro operator:

        // Set-Get block for work area 1 defined with
        // macro operator
        bSetGet := &( "{ |setVal| IF( setVal == NIL, ;
           1->FName, 1->FName := setVal ) }" )
        // Set-Get block defined using FIELDWBLOCK()

        // bSetGet created here is the functional
        // equivalent of bSetGet above
        bSetGet := FIELDWBLOCK("FName", 1)

 Files   Library is CLIPPER.LIB.


Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google photo

You are commenting using your Google account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.