[geeklog-devel] MVC package and sample application
tony at tonybibbs.com
Sun Mar 23 10:52:07 EST 2003
Blaine Lang wrote:
> Ok - I have the application installed and can see a lot of work was done to
> create these new classes. It initially appears to be a lot more complex and
> you still need to add the template classes which I gather will be the view
Yes, this example does not use a template class but in GL2 it would
without question. Hopefully you don't see this as too much more
complex. Admittedly the base MVC framework (controller.class.php,
MVC_Base.class.php, etc) can appear to be complicated. All that us GL2
developers would need to know, however, is how to build a new controller
configuration file (which shouldn't be too hard) and then simply build
the views/models accordingly.
The hardest thing starting is out is understanding object mapping. While
I don't see a big reason, the command that is typically typed into the
get string (e.g. http://example.com/?cmd=show) is mapped in the config
file to a class name (e.g. SaveContact). Then in the config file you'll
notice a bunch of _FORWARD objects for a given view or model. Those
define all the possible 'next steps' a command can take. Thus in the
end of a execute() method you'll see something like "return 'validate'".
In this case 'validate' is the name of a forward for the current model
which maps to another command OR does a redirect (doing a redirect for
forward to another view/model is determined by the _TYPE directive).
I don't like the PHP Array for configuration. If you look closely I
have started a config.xml file which I think is easier to read for the
developers *and* it provides us a way to validate the XML so ensure the
config file is valid. I think an XML config file will be more standard
way of doing configuration but for those who perfer to work with PHP
isntead, I will rework the array code to some other more intuitive method.
> I recognize there are benefits and re-use via patterns and more OO classes.
> It will just take me a bit to fully understand the architecture and the
> approach. I'm not a JAVA coder or have developed MVC programs before.
> Is this the direction you have in mind for GL2?
Yes, this is the direction I would like to take GL2. I think the base
framework will need to change a tad before anything is deemed final but
the basic MVC framework is one I would really like to use.
> Can you summarize your reasons and benefits you see with this approach vs a
> more standard OO style for the business or model layer with a template
> driven interface for the presentation (view layer) and using data
> abstraction layer.
Actually this represents the approach you just described. The only
difference is execution is marshalled by a single object, the
controller. Thus if you want to change program flow you need only edit
the configuration for the controller to forward execution to the proper
commands or, optionally, redirect to another controller within the
application (i.e. fowarding control to the admin controller, or the
Forum controller, etc). The MVC framework in addition to breaking logic
into smaller atomic parts for maximum reuse, gaurantees only the code
needed to process the current request is loaded.
Finally, as we develop the various use cases for a system (i.e.
saveUser, approveStory, etc) they map directly to views and models in
this framework so it would be quite easy to send developers off coding
from those use cases (and requirements of course).
Blaine, I'd encourage you and anybody else to build a simple form that
does something trivial like, say, adds two numbers together complete
with validation to get accustomed to this. As I said I don't want to
run down a path that the rest of you don't agree with so it is important
to me that I get a 'yea' or 'nay' from you all.
|Tony Bibbs |[R]egardless of what you may think of our penal |
|tony at tonybibbs.com |system, the fact is that every man in jail is one |
| |less potential fisherman to clutter up your |
| |favorite pool or pond. --Ed Zern |
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