Jesse Erlbaum wrote:
> As you have already identified, the Model is simply a Perl module. The most
> important thing to think of when writing a Model module is to make sure you
> make it entirely separate from the user interface. It helps me to think of
> the methods in the Model as potentially being called from a web application,
> a cron script, or an email-based interface. The Model should not contain
> anything specific about any of the interfaces through which it might be
> accessed.
Hi, Jesse. I think this part is probably an evolution from the earlier
days of CGI::Application, at least in the applications your company
wrote for my former, now defunct, employer. :)
There was a tendency to make the CGI::Application-derived modules both M
and V. I'm glad to see that's less the case these days.
My current approach is to use Mason for implementing the controller and
view, with a lot of the business logic put in the "model". I'm probably
going to explore using CGI::Application and either HTML::Template or
Template Toolkit for a current side project.
Do you have a favorite approach for writing the Model objects? At
Investorama we created a class called TableObject that would deal with
getting/setting values from the database, plus doing data verification
like checking for values being present and well-formed XML in fields
that needed it. I still use that approach on my consulting projects.
It's not a very complex object, and it doesn't do things recursively,
like mapping an attribute to an object and handling that object as well.
TableObject doesn't act as a base class. It just becomes one of the
attributes of the object.
A typical invocation is something like this:
my %fields = (
id => { type => 'num', pkey => 1, sequence => 'seq_users' },
email => { type => 'string', required => 1 },
password => { type => 'string', required => 1 },
first_name => { type => 'string', required => 1 },
last_name => { type => 'string', required => 1 },
valid => { type => 'num', required => 1},
member_id => { type => 'num' },
);
my $table = NAIC::TableObject->new(DBH => $self->dbh,
OBJECT => $self,
TABLE => 'users',
FIELDS => \%fields,
VERIFY => 1);
$table is then put into $self as an attribute called '_table'.
Storing/retrieving/verifying are done with $self->_table->store etc. It
expects that the attributes of an object like $self->email match the
database columns.
--
Barry Hoggard
Tristan Media LLC
e: [EMAIL PROTECTED]
p: 212-627-1596
aim: hoggardb
