Extensibility vs. Ease of
Use
Jesse Ezell has a
post where he criticizes my recent entry on
Tight Coupling vs. Loose Coupling. He seems to
have drawn the same conclusions
I did about Interfaces vs. Abstract classes when it
comes to versioning APIs then asks why using an
API based on abstract classes that represent an RSS
item isn't better than passing around
IXPathNavigable objects. He correctly points out
that an API based on objects is easier to code
against than one based on passing around XML.
However, the goal of passing around XML instead of
objects is flexibility and not necessarily an
easier programming model.
One of the problems with using an object model
instead of passing along data is the complexity
inherrent in trying to represent a constantly
evolving yet decentralized data format like RSS
using rigid object structures. In the post entitled
How Not To Build An Extensible Interface post I
point out the fact none of the APIs proposed even
deals with exposing all the elements of the core
RSS spec let alone extensions like Dublin Core, the
Comment API or Easy
News Topics.
To expose all data to plugins one either has to
figure out how to expose the semi-structured XML
data via the object interfaces (hashtables of key
value pairs, XmlNode objects, etc) or provide
limited interfaces as Simon and now Jesse are
proposing. So far, XML has proved to be the
mechanism of choice for exposing semi-structured
data and if one is going to expose part of the data
as XML then one might as well expose all the data
as XML.
The current application of RSS Bandit uses an
internal RssItem object which exposes
the most frequently accessed data in an RSS item as
properties (even though many of these are often
absent in feeds such as description, date or
title). However I've realized the value of exposing
all the data in the item as XML especially for
enabling flexibility and decoupling the application
from user plugins or other extension mechanisms.
For instance, providing XML views of the
RssItem object means that I can allow
people to swap out the stylesheet used to display
the RSS item in the browser pane with ease.
The primary problem I have with Jesse's solution
is that it makes plugins beholden to the
application for supporting a new RSS feature
because even with abstract classes the concrete
implementation that is passed around still needs to
be defined by the application. On the other hand,
when passing XML around users can be using version
1.0 of the aggregator and yet only have to upgrade
their various plugins to obtain support for new RSS
features. Jesse's approach ties plugins to specific
versions of an aggregator while using XML does not.
Guess which one I prefer.
#
Winforms and
the Magic Library
In a previous diary
Skywise asked why the widgets shipped in
various Microsoft devloper toolkits lag behind
third party technologies like the Magic
library. As is typical when someone complains
about a Microsoft technology there was a
quick reply that Microsoft does this for
nefarious reasons.
Of course, if you think about it this doesn't make
sense. B0rg central has nothing to lose and a lot
to gain by providing developers with cool
technologies for developing kick ass applications.
Being the pest that I am I decided to take the
issue up with our resident Winforms PM, Mike
Harsh, who stated that the limitations of the
Winforms GUI toolkit in v1.0 of the .NET framework
were due to scheduling constraints (which I now
know about all too well) and they plan to rectify
this in future releases. He mentioned that he may
be blogging about their proposed improvements in
future.
#
Look Who's
Blogging Now
I just found out that Kimbro
Staken is blogging again, subscribed.
#
Hannibal the Gangsta
Cannibal
Stories that make you go WTF:
An aspiring rap star who has been charged with
murdering his roommate and eating part of her
lung did so as part of his record label's plan to
cultivate a "gangsta" image for him, the victim's
mother charged in a lawsuit filed in Los
Angeles
Dang, what happened to traditional means of
proving how much of a thug you are like
getting
shot and living to rap about it?
#RSS
Bandit Prevents System ShutDown
A few people have complained that
when running RSS Bandit on a Win2K box attempts to
shutdown or reboot the computer are prevented
from completing. Best I could tell is that in the
Closing event setting the event's Cancel property
to True keeps even the system from being able to
close the program so that it can't reboot until the
application is manually closed.
This problem should be fixed in v1.1 of the .NET
Framework
which is available now. However if you are tied
to v1.0 of the .NET Framework the code below is a
workaround
enum WM
{
WM_CLOSE
=
0x0010,
WM_QUERYENDSESSION = 0x0011,
WM_ENDSESSION =
0x0016
}
protected override void WndProc(
ref
System.Windows.Forms.Message m)
{
if (m.Msg == (int)WM.WM_CLOSE ||
m.Msg ==
(int)WM.WM_QUERYENDSESSION ||
m.Msg ==
(int)WM.WM_ENDSESSION)
{
RssBanditView. Closing -= new
System.ComponentModel.CancelEventHandler(
RssBanditView_Closing);
base.WndProc(ref m);
RssBanditView.
Closing += new
System.ComponentModel.CancelEventHandler(
RssBanditView_Closing);
}
else
{
base.WndProc(ref m);
}
}
Shoutouts to Zhanbo from the Windows Media team for
providing this info.
#South
ParkCartman Jennifer Lopez quote:
Don't be fooled by all my money
I still like to eat Tacos, honey
It's a lot funnier with
some context#
--
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The above comments do not
represent the thoughts, intentions, plans or
strategies of my employer. They are solely my
opinion.