[cgiapp] Re: Routes and get_current_runmode()

[P Kishor]

Replying to my own email to document what I have done, and seek
further advice. Please see below --

On Mon, Aug 10, 2009 at 3:35 PM, P Kishor<punk.kish at gmail.com> wrote:
> I am experiencing a problem with C::A::P::Routes, and I think I know
> what is going wrong, but I don’t know why or how to fix it.
>
> Background: I have implemented my application with C::A::Dispatch and
> C::A::P::Authentication, and it works well. For various reasons I like
> C::A::P::Routes, and would like to use it instead of C::A::Dispatch.
> However, C::A::P::Routes doesn’t seem to respect the protected modes
> set up by C::A::P::Authentication, and shows the protected modes
> without letting the login form kick in.
>
> So, I investigated and discovered that C::A::P::Routes has a
> disconnect between what it thinks is the runmode and the value of
> $self->get_current_runmode. Here is my test --
>
> sub setup {
>    my $self = shift;
>
>        $self->start_mode('welcome');
>        $self->routes([
>
>        # unprotected runmodes
>        '/welcome' => 'welcome',
>        '/login'   => 'login',
>
>        # protected runmodes
>        '/mainpage'=> 'mainpage',
>        ]);
>
>    $self->param(protected_runmodes => ['mainpage']);
> }
>
> sub cgiapp_prerun {
>    my $self = shift;
>
>    $self->session->param('__RUN_MODE1', $self->get_current_runmode());
>    my $protected_runmodes = $self->param('protected_runmodes');
>    foreach my $rm (@$protected_runmodes) {
>        if ($self->get_current_runmode() eq $rm) {
>            $self->prerun_mode('login')
> unless($self->session->param('__LOGGED_IN'));
>            last;
>        }
>    }
>        #$self->prerun_mode('login');
>    $self->session->param('__RUN_MODE2', $self->get_current_runmode());
> }
>

In cgiapp_prerun, I changed the following line

    foreach my $rm (@$protected_runmodes) {
>        if ($self->get_current_runmode() eq $rm) {
            $self->prerun_mode('login')
unless($self->session->param('__LOGGED_IN'));
            last;
        }

to

          if ($self->prerun_mode() eq $rm) {

and now it works as expected.

Looking at the code of C::A::P::Routes, it seems to be setting the
prerun_mode() correctly, but there doesn't seem to be any method for
updating the value of get_current_runmode(). In fact, in the code for
CGI::Application itself there doesn't seem to be any easy facility for
changing the value of get_current_runmode() which seems to get its
value from $self->{__CURRENT_RUNMODE} which seems to be set in

sub run {
..
	# Set get_current_runmode() for access by user later
	$self->{__CURRENT_RUNMODE} = $rm;
}

To me, C::A::P::Routes seems more in the spirit of CGI::Application
than C::A::D is, and I would rather use Routes, but something needs to
be changed somewhere for it to work properly.


> sub mainpage {
>    my $self = shift;
>
>    my $tmpl = $self->load_tmpl('mainpage.html');
>    $tmpl->param(runmode1 => $self->session->param('__RUN_MODE1'));
>    $tmpl->param(runmode2 => $self->session->param('__RUN_MODE2'));
>    $tmpl->param(debug => $self->routes_dbg); #dumps all the
> C::A::P::Routes info
>    return $tmpl->output;
> }
>
> And, when I point my browser to ‘http://<myapp>/mainpage’ this is what I get
>
> Main Page!
>
> You are now logged in!
>
> Runmode1: welcome
>
> Runmode2: welcome
>
> Debug: $VAR1 = { 'rule_matched: ' => '/mainpage', 'parsed_params: ' =>
> {}, 'path_received: ' => '/mainpage', 'runmode: ' => 'mainpage' };
>
> See what is going on -- C::A::P::Routes correctly thinks the runmode
> is ‘mainpage’ as per the URL. However, $self->get_current_runmode()
> returns ‘welcome’ in cgiapp_prerun(), and as a result, the mainpage is
> not protected. Now, it could be that C::A::P::Routes is firing *after*
> my cgiapp_prerun() protected_mode logic is run. To test that, I
> uncommented the #$self->prerun_mode('login'); line in cgiapp_prerun(),
> and lo and behold, the runmode is changed to login.
>
> The remedy seems to be that once it has figured out the runmode
> correctly, C::A::P::Routes should set the value of
> $self->get_current_runmode() to it.
>
> If I have diagnosed the problem correctly, please help me find a fix.
> If not, please help me diagnose correctly.
>
> Many thanks,
>
>
> --
> Puneet Kishor http://www.punkish.org
> Carbon Model http://carbonmodel.org
> Charter Member, Open Source Geospatial Foundation http://www.osgeo.org
> Science Commons Fellow, http://sciencecommons.org/about/whoweare/kishor
> Nelson Institute, UW-Madison http://www.nelson.wisc.edu
> -----------------------------------------------------------------------
> Assertions are politics; backing up assertions with evidence is science
> =======================================================================
> Sent from Madison, WI, United States
>