We can go on and on. We need other people input on this.

On Oct 21, 4:32 pm, Yarko Tymciurak <resultsinsoftw...@gmail.com>
wrote:
> On Wed, Oct 21, 2009 at 4:15 PM, mdipierro <mdipie...@cs.depaul.edu> wrote:
>
> > I do not understand. Models, Views and Controller are files. You can
> > encapsulate them in folders. How would you encapsulate them in
> > classes?
>
> Models (data layer), controllers (engineering rules or business rules), and
> views (presentation layer) are separation of concerns.
> You have them separated by directories / files.
>
> Classes (by definition) encapsulate behaviors (functions), and data.
>
> > Let me put is another way.
> > This discussion has kept a plugin implementation on hold for one year
> > because I think any other implementation is going to be more clunky.
>
> I don't know what that means - I have heard you say / complain that "more
> code would have to change" - which is a sign of design coupling, so the
> natural coupling here is in the directory structure, used to hold all
> structure - it is showing its limitations perhaps.
>
> > I
> > am happy to consider alternative solutions but I want to see a fully
> > working implementation by mid November so we can release plugin specs
> > by end the of the year.
>
> You have this upside down, I think - I want to see the specs (what you want
> it to do, how you want it to behave) before you start showing me solutions
> for release.
>
> It is ok to prototype to flush out some aspects, some specs when you don't
> know - e.g. how would discovery work.  But then, back to how this fits into
> the system - that look is needed.
>
> There is no "on hold"  - if implementation were trivial, then you could just
> code it up.  Since this needs thinking specification, LACK of that talk is
> what has put this on hold.
>
> It can go out in November.  Then you will see in practice what it's
> limitations are, and iterate again in a year.  Or you can think / specify a
> little more, have things work a little better, and cut the number of big
> iterations in 1/2 or less.   Your choice.
>
>
>
> > We should continue the discussion and you should continue try convince
> > me. I do not exclude I will be working on other implementations as
> > well (that why I do not promise backward compatibility on this yet).
>
> Experience will convince you.  Or openness (willingness to try and see the
> other perspective).
>
> If you do not believe that having plugin_xxx.py files everywhere will create
> problems, then you will have to experience that.
>
> If the human side of this was not important, then the language (and aspects
> that get in your way) would not be important either.
>
> But is IS important.
>
> - Yarko
>
>
>
> > Massimo
>
> > On Oct 21, 3:54 pm, Yarko Tymciurak <resultsinsoftw...@gmail.com>
> > wrote:
> > > On Wed, Oct 21, 2009 at 3:42 PM, mdipierro <mdipie...@cs.depaul.edu>
> > wrote:
>
> > > > On Oct 21, 3:01 pm, Yarko Tymciurak <resultsinsoftw...@gmail.com>
> > > > wrote:
> > > > > On Wed, Oct 21, 2009 at 2:50 PM, mdipierro <mdipie...@cs.depaul.edu>
> > > > wrote:
>
> > > > > > As far as I am concerned think there are the only rules we need to
> > > > > > follow:
>
> > > > > > 1) a naming convention:
>
> > > > > >    models/plugin_[name].py
> > > > > >    controllers/plugin_[name].py
> > > > > >    */plugin_[name]/*
>
> > > > > This convention is spaghetti source - it is crap; I do not like it in
> > the
> > > > > least, and see absolutely no reason to even consider it.
>
> > > > > It will only lead to confusion, and novices learning to have to
> > manage
> > > > all
> > > > > sorts of code they should not be looking at, knowing about the
> > internal
> > > > > details (modularity - remember?!) - and if this is a teaching system,
> > > > even
> > > > > the more.
>
> > > > > I want to see you just DROP this convention.
> > > > > I'll repeat.  It is crap.
>
> > > > > As Thadeus points out (and I only vaguely remember - it may need more
> > > > > discussion) - Mr. Freeze proposes something more appropriately
> > > > structured.
>
> > > > > Look at it again, more seriously.
>
> > > > I did. Over and over. Let me explain why it is not crap. Think of a
> > > > matrix where the columns are models, views and controllers and the
> > > > rows are functional components like plugins.
>
> > > Then perhaps we need classes - since what you are saying is this
> > structure
> > > (the row/column layout of web2py) is not able to cleanly encapsulate
> > > components / plugins for the programmer.
>
> > > You will have students - even maintainers - looking at applications,
> > > maintaining them, with all sorts of "plugin_xyz.py" files, some in
> > > controllers, some in...
> > > and they will change them - and you will remind them (because it is not
> > well
> > > encapsulated) to ALSO change the associated models / views when they make
> > a
> > > change.... AND to remember what they SHOULD NOT do.... AND..... AND.....
>
> > > I repeat - this is crap!  ;-)  Really (the smiley is not because I am
> > > kidding, but just that I am not giving way, but trying to add something
> > to
> > > make this more friendly).   It is crap because it will lead to this in
> > the
> > > systems that go out, so one of two things are likely to occur ---- the
> > > "plugins" will be confusing, OR  people will be tempted to change them in
> > > innapproriate ways, and it will devolve into nothing more than some
> > fancy,
> > > enabled CUT-AND-PASTE opportunistic code-reuse system (not modular!).
>
> > > Trust me, if it smells like, and looks like ..... it probably is....
>
> > > >  Now we need to represent
> > > > this structure in a filesystem which has a tree like structure.
>
> > > No - YOUR solution has this constraint; I am saying look at the problem
> > > more, and reconsider your solution again...
> > > and again... and again... until it has the right shape.  IF it suggests
> > > other things that need to be rewritten, and there is a cascade of that -
> > > while dissapointing, it may be a good thing (not a bad thing).
>
> > > > Again:
> > > > we are trying to represent a matrix as a tree. You want to do it by
> > > > row (one folder for each plugin and models/views/controllers
> > > > subfolders for each plugin). I want to represent it by column (top
> > > > level models/views/controllers and files of subfolders for each plugin
> > > > within each top level folder). Why I like the second better? Because
> > > > web2py already has that structure and in fact we have that already
> > > > without changing one line in web2py.
>
> > > You are stuck in the depths of your solution here, so these arguments
> > only
> > > apply there...
>
> > > I would like to see you get out of solution mode for a few minutes, and
> > take
> > > a 50,000 meter view for a bit before you go back down to that level...
>
> > > > In order to take the other approach (the one you suggest) you would
> > > > have to represent some parts of the matrix by column (those that do
> > > > not belong to plugins) and some by row (those that belong to plugin)
> > > > and this would result in real spagetti code in the implementation and
> > > > it would constitue a major web2py rewrite. In which order should the
> > > > folders be looked up? In which order should models be executed?
>
> > > > From a logical point of view plugins can be managed as subfolders and
> > > > that is what admin already does.
>
> > > That is deployment - what about from the developer's perspective - what
> > are
> > > the implications of this mess there?!
>
> > > Ach!
>
> > > - Yarko
>
> > > > > > 2)  models/plugin_[name].py can assume ONLY db, auth, crud, T
>
> > > > > auth, crud, T are gluon defined; that's ok.
>
> > > > > db is an application level variable, so that seems potentially
> > > > problematic,
> > > > > an assumption - this either needs to be NOT shared, or a way for the
> > > > > application to configure it for plugins is needed.
>
> > > > > > 3)  models/plugin_[name].py should define only one global object
>
> > > > > >    plugin_[name]=dict()
>
> > > > > Ugh!
>
> > > > > Well, this is ONE way to do plugin registration so the system know
> > what
> > > > is
> > > > > there.  It's uglly, and brut force.  I don't even want to critique it
> > > > > because, as I've said before, the IMPORTANT point is:
>
> > > > > -  The running app needs a way to discover what plugins are
> > available,
> > > > and
> > > > > there must be a way for the plugin to somehow registrer it's
> > presence.
>
> > > > > Now:  WHAT are the important things an app / web2py  instance must
> > know
> > > > > about the plugin?
>
> > > > > - version?
> > > > > - name?
> > > > > - is it using / expecting app db connection?
> > > > > - is it creating own db connecntion?
>
> > > > > We should make a big list, and narrow it down to reasonable things
> > later.
>
> > > > > This has not been done, and is one reason why discovery (and
> > associated
> > > > > problems because of that) doesnt' yet exist.
>
> > > > This is true but at this point I am just interested in making sure
> > > > people can experiment with LOAD and make sure one plugin does not
> > > > interfere with another. What plugins should share is another story and
> > > > I am not sure I want to dictate that. I can think for example of two
> > > > different web2py  CMSes that may want to use distinct sets of
> > > > incompatible plugins and I do not see a problem with that.
>
> > > > I define "component" a LOADable action of a "plugin".
>
> > > > Massimo
--~--~---------~--~----~------------~-------~--~----~
You received this message because you are subscribed to the Google Groups 
"web2py-users" group.
To post to this group, send email to web2py@googlegroups.com
To unsubscribe from this group, send email to 
web2py+unsubscr...@googlegroups.com
For more options, visit this group at 
http://groups.google.com/group/web2py?hl=en
-~----------~----~----~----~------~----~------~--~---

Reply via email to