How do nested Events work??

Question

Could anyone Explain in Detail how Nested Events Work????
Thanx in advance!!

Answer 1

http://docs.iplanet.com/docs/manuals/uds/50/toolref.pdf
Page 159
You should read the document but there is a snippet from the doc:
Nesting event statements You can nest an event statement in your statement
block either by using another event statement or by invoking a method that
contains an event statement.
A typical example is when you want to open a new window and the Display
method for the window contains an event loop. Another example is using the
start task statement to start a new task and then use the event statement to wait
for the return or exception events.
Code Example 3-13 Nesting event statements
event loop
when <quit_button>.Click do
exit;
when <start_task>.Click do
tsk_desc : TaskDesc;
tsk_desc = start task o.meth() where completion =
event;
event loop
when o.meth_return(x = return) do
when o.meth_exception(e = exception, f = errs);
when <cancel_button>.Click do
tsk_desc.SetCancel();
end event;
when <cancel_button>.Click do
exit;
end event;
If more than one event statement is registered for the same event, the event
statement that is currently executing when the event reaches the top of the queue is
the one that handles the event. Once the event has been handled, it is removed
from the queue. Therefore, an event is never handled more than once.
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