Re: What is/is not considered to be good OO programming

From: Tony Marston (tony_at_marston-home.demon.co.uk)
Date: 12/10/03 

Date: 10 Dec 2003 06:02:48 -0800

googlemike@hotpop.com (Google Mike) wrote in message news:<25d8d6a8.0312091001.27d1e483@posting.google.com>...
> Oh what the hell. Here's my two cents...
>
> I agree with Tony Marston, if I read him right after skimming this
> thread. Brit programmers have common sense, unlike most of my American
> compatriots I have to interact with in the workplace.
>
> OOP is way overblown. If you use it right, it's great. If you use it
> wrong, and many pseudo-senior devs I've seen use it unnecessarily, it
> can do nothing but introduce unecessary complexity and even slow the
> app down.
>
> For that matter, the same argument can be made for using XSLT to
> abstract your presentation layer. XSLT is overblown and introduces
> nothing but delays, I find.

Then your guys haven't learnt how to use XSL properly. It is a
scripting language just like PHP, and as such you can make use of
standard reusable modules. For example, in my sample application
(which you can try online at
http://www.tonymarston.net/sample/index.html) I have a family of 6
components for each entity/table – list, insert, update, enquire,
delete, search – for which I need only 2 (two) XSL stylesheets. Within
each of these stylesheets I make use of the <xsl:include> and
<xsl-call-template> functions to invoke common code. When I want to
paint a data field on a form all I use is the following:

  <xsl:call-template name="datafield">
    <xsl:with-param name="item" select="tree_type_desc"/>
  </xsl:call-template>

This template/subroutine then decides how to paint the field
(display-only, single-line textbox, multi-line textbox, dropdown list,
radiogroup, checkbox, whatever) using information supplied either in
the XML file or as a parameter supplied at runtime to the XSL
transformation process.

I use similar template calls to build my action buttons, navigation
buttons, column headings, etc. They are documented at
http://www.tonymarston.net/xml-xsl/xml-and-xsl.html.

Using this technique, coupled with my own method of using
classes/objects which so many of you find objectionable, I can define
a database table and build the 6 components to maintain/display its
contents in 60 minutes. That is an average of 10 (ten) minutes per
component. How's about THEM apples!!

> The same arguments going on here in PHP are being argued like mad on
> the .NET platform too.
>
> Take for example a simple web-based checkbook app for a series of
> users. You login, see your checkbook, and can make entries to it.
> Here's what a series of developers might think:
>
> psuedo-senior dev 1: Let's make a User object, Checkbook object, Login
> object, Logout object, and an Entry object! Let's do objects for
> anything we can think of!
>
> psuedo-senior dev 2: Let's make the business layer push out nothing
> but XML, then use XSLT to style this output for the end user.
>
> psuedo-senior dev 3: I think we should make the data layer emit
> nothing but XML.
>
> psuedo-senior dev 4: I think we should make everything in stored
> procedures and make it receive and emit XML. The presentation code can
> be written in PHP to read the XML and style it with XSLT.

The simplest way to deal with people like that is to lock them in a
room and see who can produces results the fastest. The winner gets to
keep his job. THAT tends to sort out the men from the monkeys.
 
> No. Not me on any of this, even if it were something as complex as a
> Near Earth Object Tracking System, and I've been programming since
> 1979 and am 36 years old. My title says "Senior Developer". My take on
> objects, XML, and XSLT would be:
>
> 1. I'd use an associate array (better known as a hash table by us old
> f*cks), not an object, for the checkbook entry record.
>
> 2. Thinking about code-reuse for future projects, I'd bundle my
> frequently used functions in a web class, strings class, db class, and
> a settings class. That way, when I call a function (er, "method") like
> Redirect, I can understand where this method came from, and so can
> others who read my code, because I would have it listed in my code as
> $web->Redirect('page.php'). If Redirect breaks, you instantly know
> it's in the "_web.php" page (if you saw my Requires statement).
>
> 3. If an object isn't necessary, I avoid it like the plague. Not by
> inexperience, but by /experience/.

That goes for a whole host of different "thingies". I have seen
programmers try to use every "thingy" in the book just to prove they
know how to use it, which is not the same as using it effectively.

> 4. When I have to work in teams, we decide on a set of pages and a
> very small set of objects that we're going to assign to each team
> member, and then we iron these out individually for a bit with test
> harnesses. Eventually, we start sharing and interacting with each
> others stuff when these start to stabilize.
>
> 5. I like XML, but I dislike XSLT. XSLT is way, way too difficult of
> an implementation of a superbly fantastic idea. I'll wait until
> something better comes out to replace XSLT.

I suggest you learn to use XSLT effectively because it is here to
stay. Version 2.0 is in the pipeline, and the recently-released
standard for XFORMS (see http://www.w3.org/MarkUp/Forms/) which will
do away with all that non-standard javascript, is based quite heavily
on XML and XSL.

> For now, you'll see me
> doing and <% {code} %> and <%= $var %> in my code, although I try as
> much as possible to reduce interruptions in the HTML because of the
> speed hit. That's why you see me doing most of my code in the top of
> the page before the HTML tags.
>
> 6. I like XML, but I don't want to make every thing a particular OO
> layer run through it, such as making the business layer receive XML
> and emit XML.

My PHP development environment manages to mix a lot of different ideas
– procedural scripts, ‘included' scripts, objects, 3-tier architecture
(with separate presentation, business and data access layers), XML and
XSL transformations, and I like to think that I use each technique to
its best advantage. If an old fart like me can do it, then why can't
the rest of you?

Tony Marston
http://www.tonymarston.net/