Add support for proprietary "background" attribute in table elements.

Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>

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,

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';

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';

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;
+        
+    }
+    
+}
+

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;
     }
     
 }

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:();')
+        );
+    }
+    
+}
+

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>