[3.1.0] Add support for !important, with %CSS.AllowImportant

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1578 48356398-32a2-884e-a903-53898d9a118a

NEWS

@@ -29,6 +29,8 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 ! Limited support for proprietary HTML elements, namely <marquee>, sponsored
   by Chris. You can enable them with %HTML.Proprietary if your client
   demands them.
+! Support for !important CSS cascade modifier. By default, this will be stripped
+  from CSS, but you can enable it using %CSS.AllowImportant
 - Autoclose now operates iteratively, i.e. <span><span><div> now has
   both span tags closed.
 - Various HTMLPurifier_Config convenience functions now accept another parameter

library/HTMLPurifier.includes.php

@@ -81,6 +81,7 @@ require 'HTMLPurifier/AttrDef/CSS/Composite.php';
 require 'HTMLPurifier/AttrDef/CSS/Filter.php';
 require 'HTMLPurifier/AttrDef/CSS/Font.php';
 require 'HTMLPurifier/AttrDef/CSS/FontFamily.php';
+require 'HTMLPurifier/AttrDef/CSS/ImportantDecorator.php';
 require 'HTMLPurifier/AttrDef/CSS/Length.php';
 require 'HTMLPurifier/AttrDef/CSS/ListStyle.php';
 require 'HTMLPurifier/AttrDef/CSS/Multiple.php';

library/HTMLPurifier/AttrDef/CSS/ImportantDecorator.php

@@ -0,0 +1,38 @@
+<?php
+
+/**
+ * Decorator which enables !important to be used in CSS values.
+ */
+class HTMLPurifier_AttrDef_CSS_ImportantDecorator
+{
+    protected $def, $allow;
+    
+    /**
+     * @param $def Definition to wrap
+     * @param $allow Whether or not to allow !important
+     */
+    public function __construct($def, $allow = false) {
+        $this->def = $def;
+        $this->allow = $allow;
+    }
+    /**
+     * Intercepts and removes !important if necessary
+     */
+    public function validate($string, $config, $context) {
+        // test for ! and important tokens
+        $string = trim($string);
+        $is_important = false;
+        // :TODO: optimization: test directly for !important and ! important
+        if (strlen($string) >= 9 && substr($string, -9) === 'important') {
+            $temp = rtrim(substr($string, 0, -9));
+            // use a temp, because we might want to restore important
+            if (strlen($temp) >= 1 && substr($temp, -1) === '!') {
+                $string = rtrim(substr($temp, 0, -1));
+                $is_important = true;
+            }
+        }
+        $string = $this->def->validate($string, $config, $context);
+        if ($this->allow && $is_important) $string .= ' !important';
+        return $string;
+    }
+}

library/HTMLPurifier/CSSDefinition.php

@@ -202,6 +202,12 @@ class HTMLPurifier_CSSDefinition extends HTMLPurifier_Definition
             $this->doSetupProprietary($config);
         }
         
+        $allow_important = $config->get('CSS', 'AllowImportant');
+        // wrap all attr-defs with decorator that handles !important
+        foreach ($this->info as $k => $v) {
+            $this->info[$k] = new HTMLPurifier_AttrDef_CSS_ImportantDecorator($v, $allow_important);
+        }
+        
     }
     
     protected function doSetupProprietary($config) {

library/HTMLPurifier/ConfigSchema/schema/CSS.AllowImportant.txt

@@ -0,0 +1,7 @@
+CSS.AllowImportant
+TYPE: bool
+DEFAULT: false
+VERSION: 3.1.0
+--DESCRIPTION--
+This parameter determines whether or not !important cascade modifiers should
+be allowed in user CSS. If false, !important will stripped.

tests/HTMLPurifier/AttrDef/CSS/ImportantDecoratorTest.php

@@ -0,0 +1,48 @@
+<?php
+
+class HTMLPurifier_AttrDef_CSS_ImportantDecoratorTest extends HTMLPurifier_AttrDefHarness
+{
+    
+    /** Mock AttrDef decorator is wrapping */
+    protected $mock;
+    
+    function setUp() {
+        generate_mock_once('HTMLPurifier_AttrDef');
+        $this->mock = new HTMLPurifier_AttrDefMock();
+        $this->def  = new HTMLPurifier_AttrDef_CSS_ImportantDecorator($this->mock, true);
+    }
+    
+    protected function setMock($input, $output = null) {
+        if ($output === null) $output = $input;
+        $this->mock->expectOnce('validate', array($input, $this->config, $this->context));
+        $this->mock->setReturnValue('validate', $output);
+    }
+    
+    function testImportant() {
+        $this->setMock('23');
+        $this->assertDef('23 !important');
+    }
+    
+    function testImportantInternalDefChanged() {
+        $this->setMock('23', '24');
+        $this->assertDef('23 !important', '24 !important');
+    }
+    
+    function testImportantWithSpace() {
+        $this->setMock('23');
+        $this->assertDef('23 !  important  ', '23 !important');
+    }
+    
+    function testFakeImportant() {
+        $this->setMock('! foo important');
+        $this->assertDef('! foo important');
+    }
+    
+    function testStrip() {
+        $this->def  = new HTMLPurifier_AttrDef_CSS_ImportantDecorator($this->mock, false);
+        $this->setMock('23');
+        $this->assertDef('23 !  important  ', '23');
+    }
+    
+}
+

tests/HTMLPurifier/AttrDef/CSSTest.php

@@ -3,9 +3,12 @@
 class HTMLPurifier_AttrDef_CSSTest extends HTMLPurifier_AttrDefHarness
 {
     
-    function test() {
-        
+    function setup() {
+        parent::setup();
         $this->def = new HTMLPurifier_AttrDef_CSS();
+    }
+    
+    function test() {
         
         // regular cases, singular
         $this->assertDef('text-align:right;');
@@ -107,11 +110,13 @@ class HTMLPurifier_AttrDef_CSSTest extends HTMLPurifier_AttrDefHarness
         // case-insensitivity
         $this->assertDef('FLOAT:LEFT;', 'float:left;');
         
+        // !important stripping
+        $this->assertDef('float:left !important;', 'float:left;');
+        
     }
     
     function testProprietary() {
         $this->config->set('CSS', 'Proprietary', true);
-        $this->def = new HTMLPurifier_AttrDef_CSS();
         
         $this->assertDef('scrollbar-arrow-color:#ff0;');
         $this->assertDef('scrollbar-base-color:#ff6347;');
@@ -127,5 +132,10 @@ class HTMLPurifier_AttrDef_CSSTest extends HTMLPurifier_AttrDefHarness
         
     }
     
+    function testImportant() {
+        $this->config->set('CSS', 'AllowImportant', true);
+        $this->assertDef('float:left !important;');
+    }
+    
 }
 

tests/test_files.php

@@ -18,6 +18,7 @@ $test_files[] = 'HTMLPurifier/AttrDef/CSS/CompositeTest.php';
 $test_files[] = 'HTMLPurifier/AttrDef/CSS/FilterTest.php';
 $test_files[] = 'HTMLPurifier/AttrDef/CSS/FontFamilyTest.php';
 $test_files[] = 'HTMLPurifier/AttrDef/CSS/FontTest.php';
+$test_files[] = 'HTMLPurifier/AttrDef/CSS/ImportantDecoratorTest.php';
 $test_files[] = 'HTMLPurifier/AttrDef/CSS/LengthTest.php';
 $test_files[] = 'HTMLPurifier/AttrDef/CSS/ListStyleTest.php';
 $test_files[] = 'HTMLPurifier/AttrDef/CSS/MultipleTest.php';