webgui/lib/WebGUI/Middleware/StackTrace.pm
Scott Walters 13a2c359e7 Get rid of the cargo culted code about sending a text reply if the browser didn't specify
that it understands HTML.  This interacts badly with Plack::Test and doesn't have much of
a point in real life anyway, and I accidentally sent the test up that dends on this being
gone without sending this too.  Argh.  If I could send up a coherent commit just once...
2011-05-05 21:42:38 -04:00

423 lines
14 KiB
Perl

package WebGUI::Middleware::StackTrace;
use strict;
use warnings;
use parent qw/Plack::Middleware/;
use Devel::StackTrace;
use Devel::StackTrace::AsHTML;
use Try::Tiny;
use Plack::Util::Accessor qw( force no_print_errors );
use Scalar::Util 'blessed';
use Data::Dumper;
use Plack::Middleware::StackTrace;
use WebGUI::Session::Log;
BEGIN {
our $StackTraceClass = "Devel::StackTrace";
if (try { require Devel::StackTrace::WithLexicals; 1 }) {
# Optional since it needs PadWalker
$StackTraceClass = "Devel::StackTrace::WithLexicals";
}
my $old_fatal = *WebGUI::Session::Log::fatal{CODE};
no warnings 'redefine';
*WebGUI::Session::Log::fatal = sub {
my $self = shift;
my $message = shift;
$self->{_stacktrace} = $StackTraceClass->new;
$old_fatal->($self, $message, @_);
};
}
sub call {
my($self, $env) = @_;
my $res = try { $self->app->($env) };
if( my $trace = $env->{'webgui.session'}->log->{_stacktrace} ) {
undef $env->{'webgui.session'}->log->{_stacktrace}; # the stack trace modules do create circular references; this is necessary
# this should also keep us from doing this work twice if we get stacked twice
my @previous_html = $res && $res->[2] ? (map ref $_ ? @{ $_ } : $_, $res->[2]) : ();
my $text = trace_as_string($trace);
$env->{'psgi.errors'}->print($text) unless $self->no_print_errors;
my $html = eval { trace_as_html($trace, $env->{'webgui.session'}) };
$res = [500, ['Content-Type' => 'text/html; charset=utf-8'], [ utf8_safe($html), @previous_html ] ];
}
return $res;
}
sub trace_as_string {
my $trace = shift;
my $st = '';
my $first = 1;
$trace->reset_pointer;
while( my $f = $trace->next_frame ) {
$st .= "\t" unless $first;
$st .= $f->as_string($first) . "\n";
$first = 0;
}
return $st;
}
do {
no strict 'subs';
no strict 'refs';
*encode_html = *Devel::StackTrace::AsHTML::encode_html{CODE};
*_build_context = *Devel::StackTrace::AsHTML::_build_context{CODE};
# *_build_arguments = *Devel::StackTrace::AsHTML::_build_arguments{CODE};
# *_build_lexicals = *Devel::StackTrace::AsHTML::_build_lexicals{CODE};
};
sub trace_as_html {
my $trace = shift;
my $session = shift or die;
my %opt = @_;
# copied and modified render() from Devel::StackTrace::WithLexicals
# "$trace->as_html" just does "__PACKAGE__->render" in D::ST::WL
my $extras = sub { $session->url->extras(@_) };
my $msg = encode_html($trace->frame(1)->args);
my $out = qq{<!doctype html><head><title>Error: ${msg}</title>};
$opt{style} ||= \<<STYLE;
a.toggle { color: #444 }
body { margin: 0; padding: 0; background: #fff; color: #000; }
h1 { margin: 0 0 .5em; padding: .25em .5em .1em 1.5em; border-bottom: thick solid #002; background: #444; color: #eee; font-size: x-large; }
pre.message { margin: .5em 1em; }
li.frame { font-size: small; margin-top: 3em }
li.frame:nth-child(1) { margin-top: 0 }
pre.context { border: 1px solid #aaa; padding: 0.2em 0; background: #fff; color: #444; font-size: medium; }
pre .match { color: #000;background-color: #f99; font-weight: bold }
pre.vardump { margin:0 }
pre code strong { color: #000; background: #f88; }
table.lexicals, table.arguments { border-collapse: collapse }
table.lexicals td, table.arguments td { border: 1px solid #000; margin: 0; padding: .3em }
table.lexicals tr:nth-child(2n) { background: #DDDDFF }
table.arguments tr:nth-child(2n) { background: #DDFFDD }
.lexicals, .arguments { display: none }
.variable, .value { font-family: monospace; white-space: pre }
td.variable { vertical-align: top }
STYLE
if (ref $opt{style}) {
$out .= qq(<style type="text/css">${$opt{style}}</style>);
} else {
$out .= qq(<link rel="stylesheet" type="text/css" href=") . encode_html($opt{style}) . q(" />);
}
$out .= <<HEAD;
<script language="JavaScript" type="text/javascript">
function toggleThing(ref, type, hideMsg, showMsg) {
var css = document.getElementById(type+'-'+ref).style;
css.display = css.display == 'block' ? 'none' : 'block';
var hyperlink = document.getElementById('toggle-'+ref);
hyperlink.textContent = css.display == 'block' ? hideMsg : showMsg;
}
function toggleArguments(ref) {
toggleThing(ref, 'arguments', 'Hide function arguments', 'Show function arguments');
}
function toggleLexicals(ref) {
toggleThing(ref, 'lexicals', 'Hide lexical variables', 'Show lexical variables');
}
</script>
<!--
not doing asset dump right now
<link rel="stylesheet" type="text/css" href="@{[ $extras->('yui/build/treeview/assets/skins/sam/treeview.css') ]}" />
<script type="text/javascript" src="@{[ $extras->('yui/build/treeview/treeview-min.js') ]}"></script>
-->
<link rel="stylesheet" type="text/css" href="@{[ $extras->('yui/build/button/assets/skins/sam/button.css') ]}" />
<script type="text/javascript" src="@{[ $extras->('yui/build/yahoo-dom-event/yahoo-dom-event.js') ]}"></script>
<script type="text/javascript" src="@{[ $extras->('yui/build/yuiloader/yuiloader-min.js') ]}"></script>
<script type="text/javascript" src="@{[ $extras->('yui/build/event/event-min.js') ]}"></script>
<script type="text/javascript" src="@{[ $extras->('yui/build/dom/dom-min.js') ]}"></script>
<script type="text/javascript" src="@{[ $extras->('yui/build/element/element-min.js') ]}"></script>
<script type="text/javascript" src="@{[ $extras->('yui/build/button/button-min.js') ]}"></script>
</head>
<body>
<h1>Error trace</h1><pre class="message">$msg</pre><ol>
HEAD
my $accumulated_asset_info = []; # record the stack frames from when we find an asset on the call stack
$trace->reset_pointer;
$trace->next_frame; # for 1..2;
my $i = 0;
while (my $frame = $trace->next_frame) {
$i++;
$out .= join(
'',
'<li class="frame">',
$frame->subroutine ? encode_html("in " . $frame->subroutine) : '',
' at ',
$frame->filename ? encode_html($frame->filename) : '',
' line ',
$frame->line,
_build_asset_info($i, ($frame->args)[0], $accumulated_asset_info, $frame), # adds data to $accumulated_asset_info; this line added relative the stock Devel::StackTrace::AsHTML
q(<pre class="context"><code>),
_build_context($frame) || '',
q(</code></pre>),
_build_arguments($i, [$frame->args]),
$frame->can('lexicals') ? _build_lexicals($i, $frame->lexicals) : '',
q(</li>),
);
}
$out .= qq{</ol>};
# # dump the asset tree
#
# my $assets = WebGUI::Asset->getRoot($session)->getLineage(['descendants'], {returnObjects=>1});
#
# my $tree = { type => 'text', label => 'root', children => [], };
#
# for my $asset (@$assets) {
# # create a tree structure of assets matching their lineage
# # the format (arrays, hashes, fields) matches what YAHOO.treeview expects
# # when we find an asset mentioned in one of the stack trace frames above, we add the saved file/line/etc info to the label
# my $lineage = $asset->get('lineage');
# my @parts = $lineage =~ m/(.{6})/g;
# # warn "asset: $asset lineage: $lineage parts: @parts";
# my $node = $tree;
# while(@parts) {
# my $part = shift @parts;
# if((my $child_node) = grep $_->{lineage_chunk} eq $part, @{$node->{children}}) {
# $node = $child_node;
# } else {
# my $label = $asset->get('title') . ': Id: ' . $asset->getId . ' Class: ' . ref($asset);
# for my $message ( map $_->{message}, grep $_->{asset_id} eq $asset->getId, @$accumulated_asset_info ) {
# $label .= " <----- $message";
# }
# my $child_node = {
# type => 'text',
# label => $label,
# lineage_chunk => $part,
# children => [ ],
# };
# push @{$node->{children}}, $child_node;
# $node = $child_node;
# }
# }
# }
#
# use JSON::PP; # JSON::XS creates something that's mangled
# my $json_tree = JSON::PP->new->ascii->pretty->encode( [ $tree ] );
#
# warn "json_tree: $json_tree";
# do { open my $fh, '>', 'json.debug2.js' or die $!; $fh->print($json_tree); };
#
# $out .= qq{
# <ol><li>
# <div id="treeDiv1"></div>
# </ol></li>
# <script language="javascript">
# var tree = new YAHOO.widget.TreeView("treeDiv1", $json_tree);
# tree.expandAll();
# tree.draw();
# </script>
# };
$out .= "</body></html>";
return $out;
}
sub _build_asset_info {
my($id, $asset, $accumulated_asset_info, $frame) = @_;
return '' unless $asset and Scalar::Util::blessed($asset) and $asset->isa('WebGUI::Asset');
my $asset_title = $asset->get('title');
my $asset_id = $asset->getId;
my $asset_class = ref $asset;
my $message = "Stack frame number: $id AssetID: $asset_id Class: $asset_class Title: ``$asset_title''";
push @$accumulated_asset_info, { asset_id => $asset_id, message => $message, };
return $message;
}
my $dumper = sub {
my $value = shift;
$value = $$value if ref $value eq 'SCALAR' or ref $value eq 'REF';
my $d = Data::Dumper->new([ $value ]);
# $d->Indent(1)->Terse(1)->Deparse(1);
$d->Indent(1)->Terse(1)->Maxdepth(1);
chomp(my $dump = $d->Dump);
$dump;
};
# copied this in so that we could use a differently configured Data::Dumper
sub _build_arguments {
my($id, $args) = @_;
my $ref = "arg-$id";
return '' unless @$args;
my $html = qq(<p><a class="toggle" id="toggle-$ref" href="javascript:toggleArguments('$ref')">Show function arguments</a></p><table class="arguments" id="arguments-$ref">);
# Don't use while each since Dumper confuses that
for my $idx (0 .. @$args - 1) {
my $value = $args->[$idx];
my $dump = $dumper->($value);
$html .= qq{<tr>};
$html .= qq{<td class="variable">\$_[$idx]</td>};
$html .= qq{<td class="value">} . encode_html($dump) . qq{</td>};
$html .= qq{</tr>};
}
$html .= qq(</table>);
return $html;
}
# copied this in so that we could use a differently configured Data::Dumper
sub _build_lexicals {
my($id, $lexicals) = @_;
my $ref = "lex-$id";
return '' unless keys %$lexicals;
my $html = qq(<p><a class="toggle" id="toggle-$ref" href="javascript:toggleLexicals('$ref')">Show lexical variables</a></p><table class="lexicals" id="lexicals-$ref">);
# Don't use while each since Dumper confuses that
for my $var (sort keys %$lexicals) {
my $value = $lexicals->{$var};
my $dump = $dumper->($value);
$dump =~ s/^\{(.*)\}$/($1)/s if $var =~ /^\%/;
$dump =~ s/^\[(.*)\]$/($1)/s if $var =~ /^\@/;
$html .= qq{<tr>};
$html .= qq{<td class="variable">} . encode_html($var) . qq{</td>};
$html .= qq{<td class="value">} . encode_html($dump) . qq{</td>};
$html .= qq{</tr>};
}
$html .= qq(</table>);
return $html;
}
sub utf8_safe {
my $str = shift;
# NOTE: I know messing with utf8:: in the code is WRONG, but
# because we're running someone else's code that we can't
# guarnatee which encoding an exception is encoded, there's no
# better way than doing this. The latest Devel::StackTrace::AsHTML
# (0.08 or later) encodes high-bit chars as HTML entities, so this
# path won't be executed.
if (utf8::is_utf8($str)) {
utf8::encode($str);
}
$str;
}
1;
__END__
=head1 NAME
Plack^HWebGUI::Middleware::StackTrace - Displays stack trace when your app dies
=head1 SYNOPSIS
enable "+WebGUI::Middleware::StackTrace";
=head1 DESCRIPTION
This middleware is a copy and modification of L<Plack::Middleware::StackTrace>, a
middleware which catches exceptions (run-time errors) happening in your
application and displays nice stack trace screen.
This copy has been extended to display additional WebGUI specific information.
The stack trace is annotated with titles and object types of assets for
stack frames running inside of method calls to assets.
This fork of C<StackTrace> also hooks into L<WebGUI::Session::Log>.
Stack traces are generated on call to C<< $session->log->error >>
or C<< $session->log->fatal >>.
L<Plack::Middleware::StackTrace> will (almost) never display a
stack trace for WebGUI as errors are caught and turned into HTTP
C<200> replies.
You're recommended to use this middleware during the development and
use L<Plack::Middleware::HTTPExceptions> in the deployment mode as a
replacement, so that all the exceptions thrown from your application
still get caught and rendered as a 500 error response, rather than
crashing the web server.
Catching errors in streaming response is not supported.
=head1 CONFIGURATION
=over 4
=item force
enable "+WebGUI::Middleware::StackTrace", force => 1;
Force display the stack trace when an error occurs within your
application and the response code from your application is
500. Defaults to off.
The use case of this option is that when your framework catches all
the exceptions in the main handler and returns all failures in your
code as a normal 500 PSGI error response. In such cases, this
middleware would never have a chance to display errors because it
can't tell if it's an application error or just random C<eval> in your
code. This option enforces the middleware to display stack trace even
if it's not the direct error thrown by the application.
=item no_print_errors
enable "+WebGUI::Middleware::StackTrace", no_print_errors => 1;
Skips printing the text stacktrace to console
(C<psgi.errors>). Defaults to 0, which means the text version of the
stack trace error is printed to the errors handle, which usually is a
standard error.
=back
=head1 AUTHOR
Scott Walters
With code taken from:
Tatsuhiko Miyagawa E<lt>miyagawa@bulknews.netE<gt>
Tokuhiro Matsuno
Shawn M Moore
HTML generation code is ripped off from L<CGI::ExceptionManager> written by Tokuhiro Matsuno and Kazuho Oku.
=head1 SEE ALSO
L<Plack::Middleware::StackTrace>
L<Devel::StackTrace::AsHTML> L<Plack::Middleware> L<Plack::Middleware::HTTPExceptions> L<WebGUI::Session::Log>
=cut