Re: [Dancer-users] login example using before filter

5 Dec 2010

      On Sat, Dec 04, 2010 at 07:30:26AM -0600, Puneet Kishor wrote:
...
Hi Joel,
I am doing my implementation a bit differently, so the following is
all guesswork, but I think you will find it useful. See below...
Thanks for taking the time to reply.
In these formative times in my development, a few
hints mean a lot. :-)
...
Joel Roth wrote:
...
I've had some difficulties with the before filter example
provided in Dancer::Introduction.
If we pass the information via 'session' rather than 'var'
and use 'redirect' instead of 'request->path_info'
we get code that more-or-less works as expected:
before sub {
        if (!session('user') and request->path_info !~ m{^/login}) {
            session requested_path =>  request->path_info;
            redirect('/login');
        }
    };
post '/login'    =>  sub {
        # authenticate credentials
        session user =>  params->{user};
        my $path = session->{requested_path};
        session requested_path =>  undef;
        redirect $path
    };
...
Your working code above is correct. What you are doing is saving the
requested path in a session variable. That ensures that the value
persists over repeated calls. Then, you are redirecting, which
emulates a browser refresh, a brand new call to the server, this
time requesting the login page. Once at the login page, you extract
the previously requested path from the session var. All that makes
sense, and works as expected.
Yes, and my site is live, which I appreciate :-)

I've finally tracked down my problem code. The code below
works on my local machine as stand-alone using HTTP::Simple::PSGI.
However it 404s on the server using Plack::Runner and 
these mod_rewrite rules.

	RewriteEngine On
	RewriteCond %{REQUEST_FILENAME} !-f
	RewriteRule (.*) dispatch.cgi/$1

before sub {
    my $path = request->path_info;
    if (!session('user') and $path !~ m{^/login}) {
        session requested_path => $path;
        request->path_info('/login'); # 404s on server using mod_rewrite
        #redirect '/login' ;          # works
    }
};
post '/login'    => sub {
	if( validate(params->{user}, params->{pass}) ){
		session user => params->{user};
		my $path = session->{requested_path};
		session requested_path => undef;
    	session failed_login   => undef; 
		redirect $path;
	} else {
    	session failed_login => 1; # use this to trigger "failed login" message
		redirect '/login';
	}
};
...
...
And I'm also willing to patch the docs to show a complete,
successful implementation.
I haven't looked at the latest docs. If you think the docs are
misleading, definitely file an issue with the suggested complete
documentation that works.
Will do. I'd like people to see things work the first time out. :-)

Best,

Joel

-- 
Joel Roth