SV: [Phpwebsite-developers] Simple Module

[<po...@mi...>]

Hi all.

Allow me to add a few comments about the Item and Manager classes. First =
of
all sorry for my crappy English.=20

About half a year ago I started to develop modules for PHPWS (btw great =
CMS,
I love it). Just like Mike, thinking in a PHPWS-way almost gives me =
constant
headache. I'm feeling much better now, but I still have a lot of =
unsolved
questions about the right way to develop modules in PHPWS.

And to clear out any comments regarding "the right way", I just want to
mention, that I know there isn't really "a right way", but I'm kind of a
standardization freak (working as a Java Architect), and love =
frameworks,
code reuse, templates, and a standard way of coding. So I tend to spend =
a
great amount of time on this issue.

Rather than just coding modules in my own way, my goal has been to adopt =
the
PHPWS way of coding and thinking, and to reuse as much "core" code as
possible. I agree with Don regarding the use of the Item and Manager
classes, and to overcome the lack of documentation, I've looked through =
all
the mods which make use of these classes, including the Skeleton module.

Right now I have a problem with the Item and Manager classes, similar to
Mike=92s problem. My current module displays a list of items. Each item =
has a
related list of items. It looks something like this:

Manager (containing item A, B and C) -- Item (B) -- Manager (for item B: =
B1,
B2 and B3) -- Item (B1)

This structure is just like the photoalbum module, where you can have a =
lot
of albums, and each album can contain a lot of photos.

To show the first list, I use the Item and Manager classes. When the =
user
select an instance (e.g. item B), I need a new Item and Manager =
relationship
to show the detail list with information limited to the selected main =
item.

I think this should be done by creating an instance of the Manager class
with the ability to limit the selection through a parameterized =
constructor,
just like in the Item class.

Any ideas how to solve the problem the most elegant way? I think (like =
Mike)
that it's a very simple and common task, which should be, if it=92s not =
adding
to many disadvantages, taken care of by the standard PHPWS =
implementation
(no criticism here, just a nice request :-).

There is a possibility that the Item and Manager classes already has a =
way
of dealing with this functionality, and that I have overlooked the
implementation. If someone could provide the solution, whether or not I =
have
to code the solution myself, I would be very grateful.

Another problem which has raised when coding my module is the task of
validating the user input. If some mandatory information is missing, or =
some
of the submitted information doesn=92t follow the correct format, the =
user
must be provided with an error message, and probably the opportunity to
correct the input. This is not very easy to generalize, but I think a =
lot of
module developers would be very grateful, if the Skeleton module could =
be
extended further with examples of how to solve this task.

I have come around the validation in my own module by storing all =
submitted
variables, doing the validation, and if some error arise, displaying =
exactly
the same page, including the user input (the last part is very important =
for
a usability aspect). The Skeleton module (and as far as I know, all of =
the
other PHPWS mods), throw away the user input, and displays the same =
input
page, unfortunately empty.

One last thing - to all of you thinking about developing your own =
modules,
don't underestimate the power of the Item and Manager classes, just =
because
some functionality may be missing. Like Don said, making use of the Item =
and
Manager classes provides a lot of flexibility and code reuse. My advice =
is
to spend the time it takes, getting to know how to implement and use =
these
classes. And to the PHPWS team - thanks for the effort and excellent
framework so far. Please keep up the good work.

- Michael


> -----Oprindelig meddelelse-----
> Fra: php...@li... =
[mailto:phpwebsite-
> dev...@li...] P=E5 vegne af Eloi George
> Sendt: 14. april 2004 23:05
> Cc: Php...@li...
> Emne: Re: [Phpwebsite-developers] Simple Module
>=20
> Right now there's 2 schools of thought on this, Mike.
>=20
>  The Item-Manager module style came about because we wanted a way for
> new module developers to
> (1) be able to rapidly develop applications, and
> (2) decrease the memory usage of phpWebsite, because many module =
classes
> were loaded/kept in memory on each pageview.  If all of the modules =
used
> the same base class functions (PHPWS_Manager & PHPWS_Item), then less
> code would have to be kept in memory.
>=20
> Reason #1 is invalid right now because PHPWS_Manager & PHPWS_Item are
> largely undocumented & uncommented.
> Reason #2 is partially obsolete because with version 0.9-2, module
> classes stopped being automatically loaded by the core, freeing module
> developers to more finely tune which classes get loaded when.  I said
> *partially* because it still has a benefit for modules that operate on
> the same page as others.
>=20
> The Item-Manager module style also has some limitations -- one being
> that you can only take your module's capabilities so far before you =
have
> to start writing extra code to make the base classes do stuff that
> they're not designed to do, 'cause Item&Manager aren't just reuseable
> code -- it's an entire framework.  The other problem is that when you
> have an additional level of middleware code, you also increase the
> execution time of the script.  When that happens, the server can't
> handle as manu requests before it crashes.
>=20
> The other method of module writing is like Notes.  If you need a =
class,
> you use one.  You write the code to be fast and tight, doing only what
> *you* need it to do.  You can optimize queries to reduce the workload =
on
> the database server.  It's even easier to learn this way because =
either
> method requires you to learn how to use the Core classes, but you =
really
> don't ever have to look at Item or Manager if you don't want to.
>=20
> If you want to keep memory usage down, remember that include() and
> require() are your friends!  If you're not using a piece of code, =
don't
> load it.  Take a look at ArticleManager as a (non-definitive) example.
> Also, don't be afraid to unset() a variable after you're finished =
using
> it -- especially if it's using a lot of memory.
>=20
> Bottom line is -- you can decide for yourself which way to want to =
code
> the module.  From your description it sounds so simple that it may not
> even need a class!  You could most likely code the entire thing in
> /mod/yourmodule/index.php and not have your server deal with the
> overhead of creating a class.
>=20
> Geez, I kinda went off on a rant there, didn't I?
> -Eloi-
>=20
>=20
> Mike Potvin wrote:
>=20
> >Don,
> >I guess I'm not thinking in a very PHPWS-way yet :) Help me wrap my =
head
> >around this.  This is how my module works:  I have several links to =
the
> >module in various menus.  Each link passes a different parameter (in =
this
> >case an author's name).  The module selects rows from an sql database
> that
> >match that author's name and displays the results in a table.  There =
is
> no
> >user interaction required (user or deity).  What would my manager do?
> >Mike...
> >
> >
> >
> >>Regardless of how simple your module might be, making use of the
> >>Item/Manager system provides a lot of flexibility and code re-use.  =
Even
> >>if I just had a single item with a single field (much like =
skeleton), I
> >>would still use a Manager.
> >>
> >>Don
> >>
> >>