Re: designing beyond MV and (one) C
Re: designing beyond MV and (one) C
- Subject: Re: designing beyond MV and (one) C
- From: Sam Stigler <email@hidden>
- Date: Sun, 27 Jan 2008 11:09:12 -0800
You might consider looking into categories. They let you add methods
to existing classes... for example, add an -appendDOCstring:(NSData
*)wordDocument method to NSMutableAttributedString. For more, see http://developer.apple.com/documentation/Cocoa/Conceptual/ObjectiveC/Articles/chapter_4_section_1.html
. It might be more convenient for you in the long run to write all
of your parsers as categories -- if not of NSMutableAttributedString,
maybe of NSData.
On Jan 27, 2008, at 10:33 AM, Daniel Child wrote:
I'm wondering, though, whether I haven't done something strange by
setting up a RecordParsingStrategies class with no instance
variables? Or is that how you would do it in Objective-C. There's
nothing that seems to correspond exactly to the "implements" keyword
in Java, so I just made a field-less class with methods. (I guess
they could just as well have been plain functions.) If there is a
better way, please let me know. Otherwise, thanks for the tip.
On Jan 14, 2008, at 10:20 AM, email@hidden wrote:
In the MVC paradigm, do you typically use a different controller for
each major interface? Should I have three controllers, one to handle
each type of parser? Three window controllers, to handle each major
settings interface?
Look into the 'strategy' design pattern. All that you can do is
have a
single controller with appropriate
strategy for each of the file type use different strategies
dynamically for parsing them.
http://en.wikipedia.org/wiki/Strategy_pattern
I would propose a solution something like this:
A ParserController class. This will dynamically associate with a
subclass of an abstract 'ParsingStrategy'
class. Lets imagine that we are parsing an RTF, a DOC and a PDF
file.
What I would have is classes: RTFParsingStrategy,
DOCParsingStrategy and PDFParsingStrategy - all are subclasses of
ParsingStrategy. And each of these parsing strategies
will associate with appropriate window controllers of their own to
facilitate the necessary UI. I recommond having one window controller
per window. ParserController can also act as the window controller
for your 'Entry UI'. The same can have intelligence to decide which
strategy at runtime. This design makes it extremely flexible to add
new strategies as you introduce new file types.
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden
_______________________________________________
Cocoa-dev mailing list (email@hidden)
Please do not post admin requests or moderator comments to the list.
Contact the moderators at cocoa-dev-admins(at)lists.apple.com
Help/Unsubscribe/Update your Subscription:
This email sent to email@hidden