Re: [cgiapp] coding strategy
Opps, I clicked send prematurely. :-)
Brian Parker wrote:
> John Coy wrote:
>
> > Greetings all,
> >
> > I am relatively new to CGI::Application, although I'm not
> > new to Perl and to CGI scripts in general. I am curious
> > if there is a "style guide" or a recommened method for
> > implementing actions whose user-supplied input can possibly
> > change the "run method"
> >
> > For example, a common issue with respect to web input is
> > verification of user data (ie: are all fields present, is the
> > right type of data in each field, etc). Based on the outcome
> > of this verification, you may need to go to a different "screen"
> > which is handled by a different "run mode" in the CGI::Application
> > model.
> >
>
> I'm working through similar problems right now. The way I have been
> doing this is as follows. Assume a contrived fictional banking
> application. Also, 'setTmplVar' and 'process_tmpl' are my own subclass
> methods that use 'Template-Toolkit', there purpose should be fairly
> obvious to 'HTML-Template' users.
>
> This is a run-mode:
> -- begin code --
> sub showAccountTransactions {
>my $self = shift;
>my $q = $self->query();
>my $account_number = $q->param('account');
>
> # if the $account_number is invalid show a 'screen' that
> # that will prompt the user for a correct a account number
> # and then continue back to this same run-mode.
>
>my $account_obj = Account->retrieve($account_number)
> or return $self->showGetValidAccountNumAndContinue(
> "Account: $account_number is invalid. Please choose a
> correct one."
> );
>...
># add some objects to the 'template context'
>...
>return $self->process_tmpl('showAccountTransations.tmpl');
> }
> -- end code --
>
> 'showGetValidAccountNumAndContinue' would be a method of my base class
> which is general enough to be used from many different CgiApp subclasses.
> It is a 'screen' that is designed to simply collect an account number and
> continue (back to the same attempted run-mode). It looks something like
> this.
>
> -- begin code --
> sub showGetValidAccountNumAndContinue {
>my ($self,$message) = @_;
>$self->setTmplVar('message' => $message);
>my @account_objs = Account->retrieve_all();
>$self->setTmplVar('accounts' => \@account_objs);
>return $self->process_tmpl('chooseStream.html');
> }
> -- end code --
>
So, the point is, I don't think that a run-mode is a single 'screen'
(necessarily). The completion of a run-mode may require show the user
several screens to collect all of the information. These screens may be
general enough to be used in many different run-modes (across different
CgiApp subclasses). I don't like having to put these 'helper screens' in a
base class, but it is simplest.
BTW, the above example is contrived.
On a related note. Do any of you need to show the same 'view' to users from
different run modes (across different CgiApp subclasses), without doing a
client side redirect? It is simple enough to use the same template from more
than one run mode, but there is a certain amount of code that is coupled to a
template for loading the correct template variables. I'm trying to come up
with a pattern for 'view' classes that are tightly coupled to a template.
regards,
Brian
>
> >
> > I'm curious if cgiapp_prerun is the "right" place to do this
> > type of thing? Is it stylistically ok to perform various check
> > functions based on the run mode passed to cgiapp_prerun()?
> >
> > I'm also curious about any "gotchas" of calling one run mode
> > subroutine from another? For example, based on the value of
> > a "submit" button, one run mode may need to toss the activity
> > to another run mode. Again, is this better handled in
> > cgiapp_prerun() or is it ok to do it in the run mode subroutine?
> >
> > Assistance is greatly appreciated and I'll be glad to forward
> > code snippets if that would be helpful.
> >
> > Thanks!
> >
> > ---
> > John Coy
> > CTO/VP Network Operations
> > ANCI/Arkansas.Net
> >
> > -
> > Web Archive: http://www.mail-archive.com/cgiapp@lists.vm.com/
> > To unsubscribe, e-mail: [EMAIL PROTECTED]
> > For additional commands, e-mail: [EMAIL PROTECTED]
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Re: [cgiapp] coding strategy
John Coy wrote:
> Greetings all,
>
> I am relatively new to CGI::Application, although I'm not
> new to Perl and to CGI scripts in general. I am curious
> if there is a "style guide" or a recommened method for
> implementing actions whose user-supplied input can possibly
> change the "run method"
>
> For example, a common issue with respect to web input is
> verification of user data (ie: are all fields present, is the
> right type of data in each field, etc). Based on the outcome
> of this verification, you may need to go to a different "screen"
> which is handled by a different "run mode" in the CGI::Application
> model.
>
I'm working through similar problems right now. The way I have been
doing this is as follows. Assume a contrived fictional banking
application. Also, 'setTmplVar' and 'process_tmpl' are my own subclass
methods that use 'Template-Toolkit', there purpose should be fairly
obvious to 'HTML-Template' users.
This is a run-mode:
-- begin code --
sub showAccountTransactions {
my $self = shift;
my $q = $self->query();
my $account_number = $q->param('account');
# if the $account_number is invalid show a 'screen' that
# that will prompt the user for a correct a account number
# and then continue back to this same run-mode.
my $account_obj = Account->retrieve($account_number)
or return $self->showGetValidAccountNumAndContinue(
"Account: $account_number is invalid. Please choose a
correct one."
);
...
# add some objects to the 'template context'
...
return $self->process_tmpl('showAccountTransations.tmpl');
}
-- end code --
'showGetValidAccountNumAndContinue' would be a method of my base class
which is general enough to be used from many different CgiApp subclasses.
It is a 'screen' that is designed to simply collect an account number and
continue (back to the same attempted run-mode). It looks something like
this.
-- begin code --
sub showGetValidAccountNumAndContinue {
my ($self,$message) = @_;
$self->setTmplVar('message' => $message);
my @account_objs = Account->retrieve_all();
$self->setTmplVar('accounts' => \@account_objs);
return $self->process_tmpl('chooseStream.html');
}
-- end code --
>
> I'm curious if cgiapp_prerun is the "right" place to do this
> type of thing? Is it stylistically ok to perform various check
> functions based on the run mode passed to cgiapp_prerun()?
>
> I'm also curious about any "gotchas" of calling one run mode
> subroutine from another? For example, based on the value of
> a "submit" button, one run mode may need to toss the activity
> to another run mode. Again, is this better handled in
> cgiapp_prerun() or is it ok to do it in the run mode subroutine?
>
> Assistance is greatly appreciated and I'll be glad to forward
> code snippets if that would be helpful.
>
> Thanks!
>
> ---
> John Coy
> CTO/VP Network Operations
> ANCI/Arkansas.Net
>
> -
> Web Archive: http://www.mail-archive.com/cgiapp@lists.vm.com/
> To unsubscribe, e-mail: [EMAIL PROTECTED]
> For additional commands, e-mail: [EMAIL PROTECTED]
-
Web Archive: http://www.mail-archive.com/cgiapp@lists.vm.com/
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
[cgiapp] coding strategy
Greetings all, I am relatively new to CGI::Application, although I'm not new to Perl and to CGI scripts in general. I am curious if there is a "style guide" or a recommened method for implementing actions whose user-supplied input can possibly change the "run method" For example, a common issue with respect to web input is verification of user data (ie: are all fields present, is the right type of data in each field, etc). Based on the outcome of this verification, you may need to go to a different "screen" which is handled by a different "run mode" in the CGI::Application model. I'm curious if cgiapp_prerun is the "right" place to do this type of thing? Is it stylistically ok to perform various check functions based on the run mode passed to cgiapp_prerun()? I'm also curious about any "gotchas" of calling one run mode subroutine from another? For example, based on the value of a "submit" button, one run mode may need to toss the activity to another run mode. Again, is this better handled in cgiapp_prerun() or is it ok to do it in the run mode subroutine? Assistance is greatly appreciated and I'll be glad to forward code snippets if that would be helpful. Thanks! --- John Coy CTO/VP Network Operations ANCI/Arkansas.Net - Web Archive: http://www.mail-archive.com/cgiapp@lists.vm.com/ To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
