Here is a little advice for people who want some guidance on creating
their a model layer:
NOTE: This is merely a simple example, for guidance only. YMMV. There
are a million different ways to do this kind of thing, this is merely
one I have found effective.
In my apps, I generally create a BaseModel class, from which all others
inherit. In this class, I'll define a basic API that I want all models
to subscribe to. This is usually something like __get, __set,
setDataFromArray, validate (verify data is correct), filter (filter
input data), save and other common methods.
This setup lets you change the backend storage mechanism easily. If all
your model objects use the same API, you can change the underlying
storage code of all your models simultaneously and your app is
none-the-wiser.
An example:
Say I begin by using an array to store my data. Suddenly, I realize I
want to store my data inside a database. I can change all the methods in
my model to set data to a database object. Later in the project, I
decide that XML would be a better choice. I can change my methods to
write to an XML data file, and once again I don't have to change my
application code.
You can implement custom behavior by overriding methods and using the
'parent' keyword to call the BaseModel method implementation.
In most apps these days, my BaseModel class directly extends
Zend_Db_Table_Row. Extending Zend_Db_Table_Row allows my model objects,
with all their custom functionality, to be returned directly by
Zend_Db_Table function calls. Creating lists is much faster when you
don't have to iterate the result set a second time to create model
objects from them.
I usually won't override the methods I want to use from
Zend_Db_Table_Row (__get, __set, setDataFromArray). If I needed to
change my storage engine I would implement these methods in my BaseModel
to access the new data storage mechanism.
In each of my BaseModel subclasses, I'll usually add some static getter
methods.
For example:
Class User extends BaseModel {
Public static function getUser($user_id = null) {
//return a setup model object
$table = new users();//where users is your table class
If($user_id === null) {
$return = $table->createRow();
} else {
//get row from db
}
Return $return;
}
This function would return the model object for '$user_id', or an empty
object if null. You can call this method with
Each model then has a single point of origin. If I decide to change my
implementation, I can be assured that "User::getUser" always will give
me a fully qualified User object.
You can also create similar functions the will return a list of rows.
Hope this small bit of advice helps get your started.
Kevin Hallmark
PHP Developer
Bonnier Corporation
460 N Orlando Ave Suite 200
Winter Park, FL 32789
(407) 571-4960
[EMAIL PROTECTED]
-----Original Message-----
From: Karol Grecki [mailto:[EMAIL PROTECTED]
Sent: Tuesday, May 13, 2008 2:24 PM
To: [email protected]
Subject: Re: [fw-general] MVC - where can I learn more about the
"model"?
Rishi
You're not the first nor the last to be confused by this, but it's
actually
very simple once you realise it. If you remove views and controller,
what's
left? Business logic, data and anything specific to your application.
Let
say you need to represent a user in your system, or a client, those are
your
models. Often they are persistent in a database, some people even use
Zend_Db_Table as a model, but it can be anything, there are no rules of
what
model is, it's up to you and it will be determined by what you're
building.
Karol
Rishi Daryanani wrote:
>
> Hi,
> I'm a total newbie, but I am reading up on the Zend
> framework and trying out some tutorials, very useful..
> However everything I've read/tried involves the
> "application/views" and "application/controllers"
> directories to create views and controllers. I have
> not yet come across any mention of the "models"
> subdirectory.
>
> Where can I learn more about this and what it's used
> for?
>
> Am I right in assuming that I can build my own
> functionality (e.g. user login form, CMS) entirely
> with the concept of a controller and view? (but not a
> model)
>
> Many thanks
>
>
>
>
>
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