Help message Broadcasting system

[Trevor DeVore]

On Feb 11, 2010, at 4:33 PM, Andrew Kluthe wrote:

> I am converting my noble little app into the glx framework, as I've  
> realized
> that what it does will be invaluable to me in the long run.

Welcome aboard Andrew. I think you will find the framework very useful  
for application development as it provides the vital pieces that you  
need for creating and maintaining an application in Revolution.

The alternative is to spend time writing your own equivalents. While  
that would be an educational experience you don't get much bang for  
your buck.

There is still a lot of areas that need more thorough documentation so  
if you have a question ask. That usually gives me enough incentive to  
add a few lessons.

There is a Google Group you can send questions to. The link is on the  
main GLX Application Framework page.

http://www.bluemangolearning.com/revolution/software/libraries/glx-application-framework/

> A feature that was requested a couple of days ago, and I assume  
> needs to be
> developed early in the process, is for a Help system.
>
> For Example:
>
> ...
> Reading up on GLX, it said something about handling broadcasting.
>
> Can I use GLX's broadcasting features to do something like this? Am I
> misunderstanding the purpose of broadcasting? Am I spinning off into  
> the
> wrong quadrant of space?

I would go with the advice you have received from others rather than  
using the broadcasting feature of the framework.

In your situation you have multiple objects that are trying to display  
information in a central location. The data is flowing into the help  
display but nobody else really needs to know that the help display has  
been updated.

The broadcasting APIs included with the framework are relevant when  
you have lots of parties interested in any changes made to a single  
object (the reverse of what you are doing).

Basically broadcasting providers a way for any number of objects to  
sign up and say, "Hey, I want to know when object A's property is  
changed or such and such an event occurs." When object A's property is  
changed or the event occurs object A sends out a broadcast. The  
Broadcasting API dispatches messages to all the objects that signed up  
to be notified. Object A doesn't need to know who is signed up.

One concrete example that may prove useful - in one of my apps I have  
a lesson table in a SQL database. The title of a lesson can be  
displayed in a number of different places in the UI. Each UI element  
that displays the lesson title has signed up to be notified when the  
lesson title is changed in the database. When the lesson title is  
changed a broadcast is made and a message is sent out to each object  
that signed up to be notified.

-- 
Trevor DeVore
Blue Mango Learning Systems
ScreenSteps: http://www.screensteps.com
Releasable Revolution Resources for Developers: http://revolution.bluemangolearning.com