[aida] How to force an Application to refresh its view

Stefan Schmiedl s at xss.de
Wed Feb 6 22:29:27 CET 2008


On Wed, 6 Feb 2008 13:33:13 -0500
"Rob Rothwell" <r.j.rothwell at gmail.com> wrote:

> Hello...I seem to be full of questions...!
> 
> How can I force an application to refresh its view?
> 
> I am trying using the Announcement framework to send an announcement to an
> application (from another object) and then have it refresh the display to
> include new information (for example, someone else just entered some new
> data in another system).
> 
> I am getting the announcement, but when I try a "self viewMain" it executes
> the viewMain code, but does not actually change the display.  I can
> successfully display the correct information to a Transcript window...the
> web page just does not repaint.  The next time it does, however, the
> information is updated.

And that is the source and solution of your problem: You want to "push",
while web browsers usually only "pull". The browser sends a request to
the server, which in turn causes the server to render the contents
(produce html) of the requested page. This is transferred to the
browser, which in turn renders the html into a meaningful GUI.

If you don't use special "server push" technology, another way of
achieving a similar effect would be to periodically query the
application for status updates ... AJAX is used for stuff like this.

s.


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