[PHP] Implementing optional methods in a concrete class, but calling them from an abstract class.
Hi. I have an abstract base class (call it genericServiceHandler). I have concrete classes (FaxService, EmailService). The genericServiceHandler is watching for commands from an external source. The commands will always be one of a fixed set, no matter what the concrete service is. They are Pause, Continue, Start, Stop, Shutdown, PreShutdown. The genericServiceHandler has no need to process the commands. It only receives them and maybe dispatches them to the concrete class. The concrete class doesn't have to implement handlers for all of the commands, though, at a minimum, onStart() would be pretty much essential. My question relates to how should I code this. Should the base class have empty protected stubs to allowing the concrete class to override them via inheritance? Should I use __call() to capture the non-existing methods and use LSB to allow the concrete class to get the commands? I need to document this (phpdoc) to allow those designing the actual services know what to implement. The empty stubs certainly seems the easiest as I can block the scope to protected and include a full reasoning on when the method will be called (not all commands are applicable at all times). Using __call() can be documented using @method, but pretty much only a single line of description. What would you all do? Regards, Richard Quadling. -- Richard Quadling Twitter : EE : Zend @RQuadling : e-e.com/M_248814.html : bit.ly/9O8vFY -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Implementing optional methods in a concrete class, but calling them from an abstract class.
On Mon, Nov 1, 2010 at 9:13 AM, Richard Quadling rquadl...@gmail.comwrote:
Hi.
I have an abstract base class (call it genericServiceHandler).
I have concrete classes (FaxService, EmailService).
The genericServiceHandler is watching for commands from an external
source. The commands will always be one of a fixed set, no matter what
the concrete service is. They are Pause, Continue, Start, Stop,
Shutdown, PreShutdown.
The genericServiceHandler has no need to process the commands. It only
receives them and maybe dispatches them to the concrete class.
The concrete class doesn't have to implement handlers for all of the
commands, though, at a minimum, onStart() would be pretty much
essential.
My question relates to how should I code this.
Should the base class have empty protected stubs to allowing the
concrete class to override them via inheritance?
Should I use __call() to capture the non-existing methods and use LSB
to allow the concrete class to get the commands?
I need to document this (phpdoc) to allow those designing the actual
services know what to implement.
The empty stubs certainly seems the easiest as I can block the scope
to protected and include a full reasoning on when the method will be
called (not all commands are applicable at all times).
Using __call() can be documented using @method, but pretty much only a
single line of description.
What would you all do?
i would go w/ the stubbed out methods in the base class. if theres nothing
to do for the default implementation just use the 'null' pattern,
function pause() {}
__call is something of a last resort for me; i think it's best for proxies
or similar and thats about the most its useful for.
-nathan
Re: [PHP] Implementing optional methods in a concrete class, but calling them from an abstract class.
On 1 November 2010 16:27, Nathan Nobbe quickshif...@gmail.com wrote:
On Mon, Nov 1, 2010 at 9:13 AM, Richard Quadling rquadl...@gmail.com
wrote:
Hi.
I have an abstract base class (call it genericServiceHandler).
I have concrete classes (FaxService, EmailService).
The genericServiceHandler is watching for commands from an external
source. The commands will always be one of a fixed set, no matter what
the concrete service is. They are Pause, Continue, Start, Stop,
Shutdown, PreShutdown.
The genericServiceHandler has no need to process the commands. It only
receives them and maybe dispatches them to the concrete class.
The concrete class doesn't have to implement handlers for all of the
commands, though, at a minimum, onStart() would be pretty much
essential.
My question relates to how should I code this.
Should the base class have empty protected stubs to allowing the
concrete class to override them via inheritance?
Should I use __call() to capture the non-existing methods and use LSB
to allow the concrete class to get the commands?
I need to document this (phpdoc) to allow those designing the actual
services know what to implement.
The empty stubs certainly seems the easiest as I can block the scope
to protected and include a full reasoning on when the method will be
called (not all commands are applicable at all times).
Using __call() can be documented using @method, but pretty much only a
single line of description.
What would you all do?
i would go w/ the stubbed out methods in the base class. if theres nothing
to do for the default implementation just use the 'null' pattern,
function pause() {}
__call is something of a last resort for me; i think it's best for proxies
or similar and thats about the most its useful for.
-nathan
That does seem to be the best fit for me.
I can protect and docblock the methods.
Thanks Nathan.
Richard.
--
Richard Quadling
Twitter : EE : Zend
@RQuadling : e-e.com/M_248814.html : bit.ly/9O8vFY
--
PHP General Mailing List (http://www.php.net/)
To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Implementing optional methods in a concrete class, but calling them from an abstract class.
On Mon, Nov 1, 2010 at 11:13 AM, Richard Quadling rquadl...@gmail.com wrote: Hi. I have an abstract base class (call it genericServiceHandler). I have concrete classes (FaxService, EmailService). The genericServiceHandler is watching for commands from an external source. The commands will always be one of a fixed set, no matter what the concrete service is. They are Pause, Continue, Start, Stop, Shutdown, PreShutdown. The genericServiceHandler has no need to process the commands. It only receives them and maybe dispatches them to the concrete class. Right up to here, it sounded more like an interface than an abstract base class. The concrete class doesn't have to implement handlers for all of the commands, though, at a minimum, onStart() would be pretty much essential. [snip] And then it didn't. :-/ Andrew -- PHP General Mailing List (http://www.php.net/) To unsubscribe, visit: http://www.php.net/unsub.php
Re: [PHP] Implementing optional methods in a concrete class, but calling them from an abstract class.
On Mon, Nov 1, 2010 at 10:42 AM, Andrew Ballard aball...@gmail.com wrote: Right up to here, it sounded more like an interface than an abstract base class. I think there's an interface in there *and* a basic (HTTP? RPC?) implementation that receives and dispatches the messages. I would split these responsibilities into two separate classes which would allow you to wire up the services to different dispatchers over time. But to your original question, Richard, I agree with Nathan. Go with the solution that is both easy to code and and easy to read, especially given that the API is quite static. David
