From d0fdcc103e8dae6fc3425a093414605e0a33ffbf Mon Sep 17 00:00:00 2001
From: "Edward Z. Yang" <edwardzyang@thewritingpot.com>
Date: Sat, 27 Sep 2008 21:19:35 -0400
Subject: [PATCH] Add support for proprietary "background" attribute in table
 elements.

Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>
---
 NEWS                                          |  2 +
 library/HTMLPurifier.includes.php             |  1 +
 library/HTMLPurifier.safe-includes.php        |  1 +
 .../HTMLPurifier/AttrTransform/Background.php | 22 +++++++++++
 .../HTMLModule/Tidy/Proprietary.php           | 10 ++++-
 .../AttrTransform/BackgroundTest.php          | 39 +++++++++++++++++++
 .../HTMLPurifier/HTMLT/tidy-background.htmlt  |  4 ++
 7 files changed, 78 insertions(+), 1 deletion(-)
 create mode 100644 library/HTMLPurifier/AttrTransform/Background.php
 create mode 100644 tests/HTMLPurifier/AttrTransform/BackgroundTest.php
 create mode 100644 tests/HTMLPurifier/HTMLT/tidy-background.htmlt

diff --git a/NEWS b/NEWS
index c4d63a26..7ee2944c 100644
--- a/NEWS
+++ b/NEWS
@@ -34,6 +34,8 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
   improved.
 ! Experimental implementation of forms for %HTML.Trusted
 ! Track column numbers when maintain line numbers is on
+! Proprietary 'background' attribute on table-related elements converted into
+  corresponding CSS.  Thanks Fusemail for sponsoring this feature!
 - Fix two bugs in %URI.MakeAbsolute; one involving empty paths in base URLs,
   the other involving an undefined $is_folder error.
 - Throw error when %Core.Encoding is set to a spurious value. Previously,
diff --git a/library/HTMLPurifier.includes.php b/library/HTMLPurifier.includes.php
index 2700b8df..15336469 100644
--- a/library/HTMLPurifier.includes.php
+++ b/library/HTMLPurifier.includes.php
@@ -109,6 +109,7 @@ require 'HTMLPurifier/AttrDef/URI/Host.php';
 require 'HTMLPurifier/AttrDef/URI/IPv4.php';
 require 'HTMLPurifier/AttrDef/URI/IPv6.php';
 require 'HTMLPurifier/AttrDef/URI/Email/SimpleCheck.php';
+require 'HTMLPurifier/AttrTransform/Background.php';
 require 'HTMLPurifier/AttrTransform/BdoDir.php';
 require 'HTMLPurifier/AttrTransform/BgColor.php';
 require 'HTMLPurifier/AttrTransform/BoolToCSS.php';
diff --git a/library/HTMLPurifier.safe-includes.php b/library/HTMLPurifier.safe-includes.php
index f91cdbd8..22e4fd0a 100644
--- a/library/HTMLPurifier.safe-includes.php
+++ b/library/HTMLPurifier.safe-includes.php
@@ -103,6 +103,7 @@ require_once $__dir . '/HTMLPurifier/AttrDef/URI/Host.php';
 require_once $__dir . '/HTMLPurifier/AttrDef/URI/IPv4.php';
 require_once $__dir . '/HTMLPurifier/AttrDef/URI/IPv6.php';
 require_once $__dir . '/HTMLPurifier/AttrDef/URI/Email/SimpleCheck.php';
+require_once $__dir . '/HTMLPurifier/AttrTransform/Background.php';
 require_once $__dir . '/HTMLPurifier/AttrTransform/BdoDir.php';
 require_once $__dir . '/HTMLPurifier/AttrTransform/BgColor.php';
 require_once $__dir . '/HTMLPurifier/AttrTransform/BoolToCSS.php';
diff --git a/library/HTMLPurifier/AttrTransform/Background.php b/library/HTMLPurifier/AttrTransform/Background.php
new file mode 100644
index 00000000..f7f0feda
--- /dev/null
+++ b/library/HTMLPurifier/AttrTransform/Background.php
@@ -0,0 +1,22 @@
+<?php
+
+/**
+ * Pre-transform that changes proprietary background attribute to CSS.
+ */
+class HTMLPurifier_AttrTransform_Background extends HTMLPurifier_AttrTransform {
+
+    public function transform($attr, $config, $context) {
+        
+        if (!isset($attr['background'])) return $attr;
+        
+        $background = $this->confiscateAttr($attr, 'background');
+        // some validation should happen here
+        
+        $this->prependCSS($attr, "background-image:url($background);");
+        
+        return $attr;
+        
+    }
+    
+}
+
diff --git a/library/HTMLPurifier/HTMLModule/Tidy/Proprietary.php b/library/HTMLPurifier/HTMLModule/Tidy/Proprietary.php
index babbb190..41c1f78e 100644
--- a/library/HTMLPurifier/HTMLModule/Tidy/Proprietary.php
+++ b/library/HTMLPurifier/HTMLModule/Tidy/Proprietary.php
@@ -7,7 +7,15 @@ class HTMLPurifier_HTMLModule_Tidy_Proprietary extends HTMLPurifier_HTMLModule_T
     public $defaultLevel = 'light';
     
     public function makeFixes() {
-        return array();
+        $r = array();
+        $r['table@background'] = new HTMLPurifier_AttrTransform_Background();
+        $r['td@background']    = new HTMLPurifier_AttrTransform_Background();
+        $r['th@background']    = new HTMLPurifier_AttrTransform_Background();
+        $r['tr@background']    = new HTMLPurifier_AttrTransform_Background();
+        $r['thead@background'] = new HTMLPurifier_AttrTransform_Background();
+        $r['tfoot@background'] = new HTMLPurifier_AttrTransform_Background();
+        $r['tbody@background'] = new HTMLPurifier_AttrTransform_Background();
+        return $r;
     }
     
 }
diff --git a/tests/HTMLPurifier/AttrTransform/BackgroundTest.php b/tests/HTMLPurifier/AttrTransform/BackgroundTest.php
new file mode 100644
index 00000000..d64d87cd
--- /dev/null
+++ b/tests/HTMLPurifier/AttrTransform/BackgroundTest.php
@@ -0,0 +1,39 @@
+<?php
+
+class HTMLPurifier_AttrTransform_BackgroundTest extends HTMLPurifier_AttrTransformHarness
+{
+    
+    function setUp() {
+        parent::setUp();
+        $this->obj = new HTMLPurifier_AttrTransform_Background();
+    }
+    
+    function testEmptyInput() {
+        $this->assertResult( array() );
+    }
+    
+    function testBasicTransform() {
+        $this->assertResult(
+            array('background' => 'logo.png'),
+            array('style' => 'background-image:url(logo.png);')
+        );
+    }
+    
+    function testPrependNewCSS() {
+        $this->assertResult(
+            array('background' => 'logo.png', 'style' => 'font-weight:bold'),
+            array('style' => 'background-image:url(logo.png);font-weight:bold')
+        );
+    }
+    
+    function testLenientTreatmentOfInvalidInput() {
+        // notice that we rely on the CSS validator later to fix this invalid
+        // stuff
+        $this->assertResult(
+            array('background' => 'logo.png);foo:('),
+            array('style' => 'background-image:url(logo.png);foo:();')
+        );
+    }
+    
+}
+
diff --git a/tests/HTMLPurifier/HTMLT/tidy-background.htmlt b/tests/HTMLPurifier/HTMLT/tidy-background.htmlt
new file mode 100644
index 00000000..26dc21a9
--- /dev/null
+++ b/tests/HTMLPurifier/HTMLT/tidy-background.htmlt
@@ -0,0 +1,4 @@
+--HTML--
+<table background="logo.png"><tr><td>asdf</td></tr></table>
+--EXPECT--
+<table style="background-image:url(logo.png);"><tr><td>asdf</td></tr></table>