WebGUI::Content::PDFGenerator

docs/changelog/7.x.x.txt

@@ -1,4 +1,6 @@
 7.10.21
+ - added the optional WebGUI::Content::PDFGenerator, not enabled by default
+   (see the module's documentation).
 
 7.10.20
  - fixed: Do not call group methods on an undefined value.

lib/WebGUI/Content/PDFGenerator.pm

@@ -0,0 +1,125 @@
+package WebGUI::Content::PDFGenerator;
+
+use warnings;
+use strict;
+
+use List::Util qw(first);
+use Scope::Guard qw(guard);
+use WebGUI::Session;
+use WebGUI::Content::Asset;
+use WebGUI::Cache;
+
+=head1 NAME
+
+WebGUI::Content::PDFGenerator
+
+=head1 DESCRIPTION
+
+Generates a PDF of the requested URL when op=generatePdf.
+
+=head1 PREREQUISITES
+
+This handler depends on wkpdftohtml, which does not ship with WebGUI and is,
+as of this writing, still in active development. This handler was written for
+version 0.9.9. It is available from http://code.google.com/p/wkhtmltopdf/.
+Compiling is rather difficult, but static binaries are available for the most
+popular platforms.
+
+=head1 INSTALLATION
+
+Enable this content handler in your WebGUI config file, placing it somewhere
+before WebGUI::Content::Operation, and add a pdfGen section to your config
+file at the top level. This must contain the path to your wkhtmltopdf
+executable, a cache timeout (how many seconds to cache the pdf), and
+optionally the userId of a user to view the page as (defaults to Visitor). It
+can also contain additional command line arguments to pass to wkhtmltopdf.
+
+    "pdfGen" : {
+        "exe" : "/usr/local/bin/wkhtmltopdf",
+        "args" : "--orientation Landscape",
+        "userId" : "_f7d61hs6djh0fjnxqw21",
+        "cacheTimeout" : 3600 # 1 hour cache timeout
+    },
+    "contentHandlers" : [
+        #...
+        "WebGUI::Content::PDFGenerator",
+        #...
+        "WebGUI::Content::Operation",
+        #...
+        "WebGUI::Content::NotFound"
+   ],
+
+=cut
+
+#-------------------------------------------------------------------
+# Return the cached pdf, generating if necessary.
+
+sub cache {
+    my $asset   = shift;
+    my $session = $asset->session;
+    my $key     = [
+        'PDFGen', $session->url->getRequestedUrl, $asset->get('revisionDate'),
+    ];
+    my $cache   = WebGUI::Cache->new($session, $key);
+    my $content = $cache->get;
+    unless ($content) {
+        $content = generate($asset);
+        $cache->set($content, $session->config->get('pdfGen/cacheTimeout'));
+    }
+    return $content;
+}
+
+#-------------------------------------------------------------------
+# Generate the pdf unconditionally and return it as a string.
+
+sub generate {
+    my $asset   = shift;
+    my $session = $asset->session;
+    my $url     = $session->url;
+    my $c       = $session->config;
+    my $o       = $c->get('pdfGen');
+    my $login   = WebGUI::Session->open($c->getWebguiRoot, $c->getFilename);
+    my $guard   = guard { $login->var->end; $login->close };
+    $login->user({ userId => $o->{userId} || 1 });
+    my @args = (
+        $o->{exe}, @{$o->{args} || []},
+        '--cookie', $c->get('cookieName'), $login->getId,
+        $url->getSiteURL . $url->gateway($url->getRequestedUrl),
+        '-'
+    );
+
+    # We're using backticks because trying to run external programs from a
+    # mod_perl process is extremely tricky any other way, but TODO: figure out
+    # use a real call and pass an array of args, as that would be safer.
+    my $cmd = join ' ', @args;
+    `$cmd`;
+}
+
+#-------------------------------------------------------------------
+# Figure out which asset we need to check permissions for
+
+sub getRequestedAsset {
+    my $session  = shift;
+    my $assetUrl = $session->url->getRequestedUrl;
+    my $perms    = WebGUI::Content::Asset::getUrlPermutations($assetUrl);
+    foreach my $url (@$perms) {
+        if (my $asset = WebGUI::Content::Asset::getAsset($session, $url)) {
+            return $asset;
+        }
+    }
+}
+
+#-------------------------------------------------------------------
+# Top-level handler.
+
+sub handler {
+    my $session = shift;
+    my $op = $session->form->get('op');
+    return undef unless $op && $op eq 'generatePdf';
+    my $asset = getRequestedAsset($session);
+    return $session->privilege->noAccess unless $asset->canView;
+    $session->http->setMimeType('application/pdf');
+    return cache($asset);
+}
+
+1;