Added exception handling

Added error doc mapping
Moved more logic into Session middleware
Added Credit example to app.psgi
Made StackTrace and Debug panel automatically turn on when debug mode enabled
Fixed errorHandler

TODO

@@ -1,14 +1,17 @@
 TODO
 * Deprecate WebGUI::Session::HTTP - replace with WebGUI::Request/Response
+* Delete lib/WebGUI/URL and replace with new Middleware(s)
+* Investigate moving Cookie handling into middleware
+* Turn html debug output into a Plack::Middleware::Debug panel
 
 DONE
 * $session->request is now a Plack::Request object
 * serverObject gone from WebGUI::Session::open()
 * WebGUI::authen API changed
 * urlHandler API changed - no longer gets server, config
 * Streaming response body
-* Delete lib/WebGUI/URL and replace with new Middleware(s)
 * Mostly decoupled WebGUI from Log4perl
+* Exception handling and error doc mapping
 
 NB
 * Periodically do a big stress-test and check for leaks, mysql overload etc..

app.psgi

@@ -3,17 +3,18 @@ use Plack::Builder;
 use lib '/data/WebGUI/lib';
 use WebGUI;
 
-my $wg = WebGUI->new( root => '/data/WebGUI', site => 'dev.localhost.localdomain.conf' );
+my $root = '/data/WebGUI';
+my $wg = WebGUI->new( root => $root, site => 'dev.localhost.localdomain.conf' );
 
 builder {
-    enable 'Debug', panels => [ qw(Environment Response Timer Memory Session DBITrace PerlConfig Response) ];
-    enable 'Log4perl', category => 'mysite', conf => $wg->config->getWebguiRoot . '/etc/log.conf';
+
+    enable 'Log4perl', category => 'mysite', conf => "$root/etc/log.conf";
+    enable 'Static', root => $root, path => sub { s{^/\*give-credit-where-credit-is-due\*$}{docs/credits.txt} };
     
     # Open/close the WebGUI::Session at the outer-most onion layer
-    enable '+WebGUI::Middleware::Session', config => $wg->config;
-
-    # Any additional WebGUI Middleware goes here
-    # ..
+    enable '+WebGUI::Middleware::Session', 
+        config => $wg->config;#,
+        #error_docs => { 500 => "$root/www/maintenance.html" };
 
     # Return the app
     $wg;

lib/WebGUI.pm

@@ -220,7 +220,7 @@ sub handle {
             # non-empty output should be used as the response body
             elsif (defined $output && $output ne "") {
                 # Auto-set the headers
-                $session->http->sendHeader; # TODO: should be renamed setHeader
+                $session->http->sendHeader;
 
                 # Use contentHandler's return value as the output
                 $session->output->print($output);

lib/WebGUI/Middleware/Debug.pm

@@ -0,0 +1,39 @@
+package WebGUI::Middleware::Debug;
+use strict;
+use parent qw(Plack::Middleware);
+use Plack::Middleware::StackTrace;
+use Plack::Middleware::Debug;
+use Plack::Middleware::HttpExceptions;
+
+=head1 NAME
+
+WebGUI::Middleware::Debug - 
+
+=head1 DESCRIPTION
+
+This is PSGI middleware for WebGUI that 
+
+=cut
+
+sub call {
+    my ( $self, $env ) = @_;
+
+    my $session = $env->{'webgui.session'} or die 'WebGUI::Session missing';
+
+    my $app = $self->app;
+
+    if ( $session->log->canShowDebug ) {
+        warn 'seeing webgui.debug';
+        $env->{'webgui.debug'} = 1;
+        $app = Plack::Middleware::StackTrace->wrap($app);
+        $app = Plack::Middleware::Debug->wrap( $app,
+            panels => [qw(Environment Response Timer Memory Session DBITrace PerlConfig Response)] );
+    }
+
+    # Turn exceptions into HTTP errors
+    $app = Plack::Middleware::HTTPExceptions->wrap( $app );
+
+    return $app->($env);
+}
+
+1;

lib/WebGUI/Middleware/Session.pm

@@ -3,8 +3,13 @@ use strict;
 use parent qw(Plack::Middleware);
 use WebGUI::Config;
 use WebGUI::Session;
+use Try::Tiny;
+use Plack::Middleware::StackTrace;
+use Plack::Middleware::Debug;
+use Plack::Middleware::HTTPExceptions;
+use Plack::Middleware::ErrorDocument;
 
-use Plack::Util::Accessor qw( config );
+use Plack::Util::Accessor qw( config error_docs );
 
 =head1 NAME
 
@@ -26,13 +31,39 @@ and not worry about closing it.
 sub call {
     my ( $self, $env ) = @_;
 
+    my $app   = $self->app;
     my $config = $self->config or die 'Mandatory config parameter missing';
 
-    # Open the Session
-    $env->{'webgui.session'} = WebGUI::Session->open( $config->getWebguiRoot, $config, $env );
+    my $session = try {
+        $env->{'webgui.session'} = WebGUI::Session->open( $config->getWebguiRoot, $config, $env );
+    };
+
+    if (!$session) {
+        # We don't have access to a db connection to find out if the user is allowed to see
+        # a verbose error message or not, so resort to a generic Internal Server Error
+        # (using the error_docs mapping)
+        return Plack::Middleware::ErrorDocument->wrap( 
+            sub { [ 500, [], [] ] }, 
+            %{ $self->error_docs } )->($env);
+    }
+
+    my $debug = $session->log->canShowDebug;
+    if ($debug) {
+        $app = Plack::Middleware::StackTrace->wrap($app);
+        $app = Plack::Middleware::Debug->wrap( $app,
+            panels => [qw(Environment Response Timer Memory Session DBITrace PerlConfig Response)] );
+    }
+
+    # Turn exceptions into HTTP errors
+    $app = Plack::Middleware::HTTPExceptions->wrap($app);
+
+    # HTTP error document mapping
+    if ( !$debug && $self->error_docs ) {
+        $app = Plack::Middleware::ErrorDocument->wrap( $app, %{ $self->error_docs } );
+    }
 
     # Run the app
-    my $res = $self->app->($env);
+    my $res = $app->($env);
 
     # Use callback style response
     return $self->response_cb(

lib/WebGUI/Session/ErrorHandler.pm

@@ -19,6 +19,7 @@ use strict;
 use JSON;
 use HTML::Entities qw(encode_entities);
 use Log::Log4perl;
+use WebGUI::Exception;
 
 =head1 NAME 
 
@@ -221,33 +222,43 @@ sub fatal {
 	my $message = shift;
 
     local $Log::Log4perl::caller_depth = $Log::Log4perl::caller_depth + 2;
-	$self->session->http->setStatus("500","Server Error");
-	$self->session->response->content_type('text/html') if ($self->session->response);
 	$self->getLogger->({ level => 'fatal', message => $message });
 	$self->getLogger->({ level => 'debug', message => "Stack trace for FATAL ".$message."\n".$self->getStackTrace() });
-	$self->session->http->sendHeader if ($self->session->response);
 
+    my $error;
 	if (! defined $self->session->db(1)) {
 		# We can't even _determine_ whether we can show the debug text.  Punt.
-		$self->session->output->print("<h1>Fatal Internal Error</h1>");
+		$error = q{<h1>Fatal Internal Error</h1>};
 	} 
 	elsif ($self->canShowDebug()) {
-		$self->session->output->print("<h1>WebGUI Fatal Error</h1><p>Something unexpected happened that caused this system to fault.</p>\n",1);
-		$self->session->output->print("<p>".$message."</p>\n",1);
-		$self->session->output->print("<pre>" . encode_entities($self->getStackTrace) . "</pre>", 1);
-		$self->session->output->print($self->showDebug(),1);
+	    my $stack = encode_entities($self->getStackTrace);
+	    my $debug = $self->showDebug();
+		$error = <<END_HTML;
+<h1>WebGUI Fatal Error</h1>
+<p>Something unexpected happened that caused this system to fault.</p>
+<p>$message</p>
+<pre>$stack</pre>
+$debug
+END_HTML
 	} 
 	else {
 		# NOTE: You can't internationalize this because with some types of errors that would cause an infinite loop.
-		$self->session->output->print("<h1>Problem With Request</h1>
-		We have encountered a problem with your request. Please use your back button and try again.
-		If this problem persists, please contact us with what you were trying to do and the time and date of the problem.<br />",1);
-		$self->session->output->print('<br />'.$self->session->setting->get("companyName"),1);
-		$self->session->output->print('<br />'.$self->session->setting->get("companyEmail"),1);
-		$self->session->output->print('<br />'.$self->session->setting->get("companyURL"),1);
+		my $company = $self->session->setting->get("companyName");
+		my $email = $self->session->setting->get("companyEmail");
+		my $url = $self->session->setting->get("companyURL");
+
+		$error = <<END_HTML;
+<h1>Problem With Request</h1>
+We have encountered a problem with your request. Please use your back button and try again.
+If this problem persists, please contact us with what you were trying to do and the time and date of the problem.<br />
+<br />$company
+<br />$email
+<br />$url
+END_HTML
 	}
-	$self->session->close();
-    last WEBGUI_FATAL;
+
+	# Fatal errors cause an exception to be thrown
+	WebGUI::Error->throw( error => $error );
 }