Re: [PHP] Multiple Class Inheritance

2010-01-27 Thread Rene Veerman 
If you want m-inheritance, you can include (encapsulate is the word
i think) your smaller classes in midware and big top-level classes
that expose (part of) their interfaces. It's easy.

But guard against creating too many dependencies between different
smaller classes to and bigger classes.

Logic extending the features of more than 1 smaller class for a
special use-case should be in a bigger class that loads instances of
the smaller classes.
Do consider building 3 to 5 layers of encapsulation, when 2 seems not
enough. A class that includes  extends features for 2 to 4 small
classes is better than a class that includes 50 small classes for
widely varying features.

Logic extending the features of just 1 smaller class, even for a
special use case used only once, should be placed inside the smaller
class (possibly activated by an $options=array(), or maybe by adding
_descriptionOfUseCase to the function-name. That may seem to lead to
bloat, but zend will take care of that.

Ultimately, classes should provide abstractions of top-, mid- and
lower-level areas of business-logic.
They govern a problem-area.

Case in point; adodb.sf.net; it does database abstraction, for many
different server types, and nothing more than that.
It's finished, because all the use-cases you'll ever encounter in
the problem-area have been coded into adodb.


On Wed, Jan 27, 2010 at 1:52 PM, Ashley Sheridan
a...@ashleysheridan.co.uk wrote:
 Hi All,

 I know that a class can only inherit from one other single class in PHP,
 but how would I go about simulating a multiple class inheritance? For
 example, if I had several small classes that dealt with things like form
 generation, navbar generation, etc, how could I create a class in which
 these all existed?

 Or am I thinking about this the wrong way? Should I have keep the
 smaller classes, and have one larger object containing instances of each
 as and how are necessary?

 I've used classes before, but I'm fairly new to class inheritance, and
 more particularly, the complex inheritance like I describe here.

 Thanks,
 Ash
 http://www.ashleysheridan.co.uk




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Re: [PHP] Multiple Class Inheritance

2010-01-27 Thread Rene Veerman 
Oh, and i'd allow 1 (or _maybe_ 2) very big super-class(es) at the
top level of a framework / cms, that do include 50-100 smaller
classes.

midware classes can evolve (be extracted) from the superclass, as
your app evolves.
Try to keep groups of functions relating to as few smaller/lower
classes as possible, to allow that to happen naturally.

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Re: [PHP] Multiple Class Inheritance

2010-01-27 Thread Ryan Sun 
1, you can implement multiple interfaces

2, you may want to return object instead of extending classes,
eg.
class Small_Class_Abstract
{
  public function getFormGeneration()
  {
return new Form_Generation();
  }
}
class Small_Class_A extends Small_Class_Abstract
{
}
$A = new Small_Class_A();
$form = $A-getFormGeneration()-newForm();

On Wed, Jan 27, 2010 at 7:52 AM, Ashley Sheridan
a...@ashleysheridan.co.ukwrote:

 Hi All,

 I know that a class can only inherit from one other single class in PHP,
 but how would I go about simulating a multiple class inheritance? For
 example, if I had several small classes that dealt with things like form
 generation, navbar generation, etc, how could I create a class in which
 these all existed?

 Or am I thinking about this the wrong way? Should I have keep the
 smaller classes, and have one larger object containing instances of each
 as and how are necessary?

 I've used classes before, but I'm fairly new to class inheritance, and
 more particularly, the complex inheritance like I describe here.

 Thanks,
 Ash
 http://www.ashleysheridan.co.uk

Re: [PHP] Multiple Class Inheritance

2010-01-27 Thread Richard Quadling 
2010/1/27 Ryan Sun ryansu...@gmail.com:
 1, you can implement multiple interfaces

 2, you may want to return object instead of extending classes,
 eg.
 class Small_Class_Abstract
 {
  public function getFormGeneration()
  {
    return new Form_Generation();
  }
 }
 class Small_Class_A extends Small_Class_Abstract
 {
 }
 $A = new Small_Class_A();
 $form = $A-getFormGeneration()-newForm();

 On Wed, Jan 27, 2010 at 7:52 AM, Ashley Sheridan
 a...@ashleysheridan.co.ukwrote:

 Hi All,

 I know that a class can only inherit from one other single class in PHP,
 but how would I go about simulating a multiple class inheritance? For
 example, if I had several small classes that dealt with things like form
 generation, navbar generation, etc, how could I create a class in which
 these all existed?

 Or am I thinking about this the wrong way? Should I have keep the
 smaller classes, and have one larger object containing instances of each
 as and how are necessary?

 I've used classes before, but I'm fairly new to class inheritance, and
 more particularly, the complex inheritance like I describe here.

 Thanks,
 Ash
 http://www.ashleysheridan.co.uk





The Decorator pattern is an option here too I would guess.


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Re: [PHP] Multiple Class Inheritance

2010-01-27 Thread Nathan Nobbe 
On Wed, Jan 27, 2010 at 5:52 AM, Ashley Sheridan
a...@ashleysheridan.co.ukwrote:

 Hi All,

 I know that a class can only inherit from one other single class in PHP,
 but how would I go about simulating a multiple class inheritance? For
 example, if I had several small classes that dealt with things like form
 generation, navbar generation, etc, how could I create a class in which
 these all existed?

 Or am I thinking about this the wrong way? Should I have keep the
 smaller classes, and have one larger object containing instances of each
 as and how are necessary?

 I've used classes before, but I'm fairly new to class inheritance, and
 more particularly, the complex inheritance like I describe here.


you should study the concept of composition as it pertains to OOP.

also, there are several threads in the archives regarding multiple
inheritance in PHP.

-nathan