{CONDITION_BEGIN}
Syntax
Arguments
- Logical_Expression
An expression that evaluates to TRUE (.T.) or FALSE (.F.).
Description
Make portions of an Xdialog visible.
Discussion
{CONDITION_BEGIN} allows you to make portions of an Xdialog visible if a Logical_Expression is .T. This command is a variant of the {CONDITION} command, and is particularly useful when you have nested {CONDITION} statements. Each call to {CONDITION_BEGIN} adds the specified logical expression to the current "ambient" logical expression (i.e. the logical expression which controls whether the controls in an Xdialog are visible or not). The corresponding {CONDITION_END} command removes the most recently added logical expression from the current "ambient" logical expression.
Example
a = .f.
b = .f.
c = .f.
ui_dlg_box("",<<%dlg%
(a) A;
{condition_begin=a}
(b) B \(requires A is true);
{condition_begin=b}
(c) \(C requires A and B are true);
{condition_begin=c}
This is 3 conditions deep \(requires A, B and C are true);
{condition_end}
{condition_end}
{condition_end}
This is at the top level \(does not require that A is true);
%dlg%)
Here is how the same Xdialog would be created using the older {CONDITION} command:
a = .f.
b = .f.
c = .f.
ui_dlg_box("",<<%dlg%
(a) A;
{condition_begin=a}
(b) B \(requires A is true);
{condition=a.and.b}
(c) \(C requires A and B are true);
{condition=a.and.b.and.c}
This is 3 conditions deep \(requires A, B and C are true);
{condition=.t.}
This is at the top level \(does not require that A is true);
%dlg%)Limitations
Desktop applications only
See Also