[1.7.0] Add native support for required elements

- Factored out large portion of ValidateAttributes to AttrValidator
- Implemented ValidateAttributes armor
- Fix clear cache bug
- Implement armoring for ValidateAttributes

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1174 48356398-32a2-884e-a903-53898d9a118a

NEWS

@@ -40,6 +40,7 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 ! Config object gives more friendly error messages when things go wrong
 ! Advanced API implemented: easy functions for creating elements (addElement)
   and attributes (addAttribute) on HTMLDefinition
+! Add native support for required attributes
 - Deprecated and removed EnableRedundantUTF8Cleaning. It didn't even work!
 - DOMLex will not emit errors when a custom error handler that does not
   honor error_reporting is used
@@ -63,6 +64,7 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
 . DirectLex can now track line-numbers
 . Preliminary error collector is in place, although no code actually reports
   errors yet
+. Factor out most of ValidateAttributes to new AttrValidator class
 
 1.6.1, released 2007-05-05
 ! Support for more deprecated attributes via transformations:

library/HTMLPurifier/AttrCollections.php

@@ -82,19 +82,47 @@ class HTMLPurifier_AttrCollections
      * @param $attr_types HTMLPurifier_AttrTypes instance
      */
     function expandIdentifiers(&$attr, $attr_types) {
+        
+        // because foreach will process new elements we add, make sure we
+        // skip duplicates
+        $processed = array();
+        
         foreach ($attr as $def_i => $def) {
+            // skip inclusions
             if ($def_i === 0) continue;
-            if (!is_string($def)) continue;
+            
+            if (isset($processed[$def_i])) continue;
+            
+            // determine whether or not attribute is required
+            if ($required = (strpos($def_i, '*') !== false)) {
+                // rename the definition
+                unset($attr[$def_i]);
+                $def_i = trim($def_i, '*');
+                $attr[$def_i] = $def;
+            }
+            
+            $processed[$def_i] = true;
+            
+            // if we've already got a literal object, move on
+            if (is_object($def)) {
+                // preserve previous required
+                $attr[$def_i]->required = ($required || $attr[$def_i]->required);
+                continue;
+            }
+            
             if ($def === false) {
                 unset($attr[$def_i]);
                 continue;
             }
+            
             if ($t = $attr_types->get($def)) {
                 $attr[$def_i] = $t;
+                $attr[$def_i]->required = $required;
             } else {
                 unset($attr[$def_i]);
             }
         }
+        
     }
     
 }

library/HTMLPurifier/AttrDef.php

@@ -14,11 +14,17 @@ class HTMLPurifier_AttrDef
 {
     
     /**
-     * Tells us whether or not an HTML attribute is minimized. Only the
-     * boolean attribute vapourware would use this.
+     * Tells us whether or not an HTML attribute is minimized. Has no
+     * meaning in other contexts.
      */
     var $minimized = false;
     
+    /**
+     * Tells us whether or not an HTML attribute is required. Has no
+     * meaning in other contexts
+     */
+    var $required = false;
+    
     /**
      * Validates and cleans passed string according to a definition.
      * 

library/HTMLPurifier/AttrTransform/ImgRequired.php

@@ -20,7 +20,10 @@ HTMLPurifier_ConfigSchema::define(
 );
 
 /**
- * Post-transform that ensures the required attrs of img (alt and src) are set
+ * Transform that supplies default values for the src and alt attributes
+ * in img tags, as well as prevents the img tag from being removed
+ * because of a missing alt tag. This needs to be registered as both
+ * a pre and post attribute transform.
  */
 class HTMLPurifier_AttrTransform_ImgRequired extends HTMLPurifier_AttrTransform
 {
@@ -29,6 +32,7 @@ class HTMLPurifier_AttrTransform_ImgRequired extends HTMLPurifier_AttrTransform
         
         $src = true;
         if (!isset($attr['src'])) {
+            if ($config->get('Core', 'RemoveInvalidImg')) return $attr;
             $attr['src'] = $config->get('Attr', 'DefaultInvalidImage');
             $src = false;
         }

library/HTMLPurifier/AttrValidator.php

@@ -0,0 +1,105 @@
+<?php
+
+class HTMLPurifier_AttrValidator
+{
+    
+    
+    function validateToken($token, &$config, &$context) {
+            
+        $definition = $config->getHTMLDefinition();
+        
+        // create alias to global definition array, see also $defs
+        // DEFINITION CALL
+        $d_defs = $definition->info_global_attr;
+        
+        // copy out attributes for easy manipulation
+        $attr = $token->attr;
+        
+        // do global transformations (pre)
+        // nothing currently utilizes this
+        foreach ($definition->info_attr_transform_pre as $transform) {
+            $attr = $transform->transform($attr, $config, $context);
+        }
+        
+        // do local transformations only applicable to this element (pre)
+        // ex. <p align="right"> to <p style="text-align:right;">
+        foreach ($definition->info[$token->name]->attr_transform_pre
+            as $transform
+        ) {
+            $attr = $transform->transform($attr, $config, $context);
+        }
+        
+        // create alias to this element's attribute definition array, see
+        // also $d_defs (global attribute definition array)
+        // DEFINITION CALL
+        $defs = $definition->info[$token->name]->attr;
+        
+        // iterate through all the attribute keypairs
+        // Watch out for name collisions: $key has previously been used
+        foreach ($attr as $attr_key => $value) {
+            
+            // call the definition
+            if ( isset($defs[$attr_key]) ) {
+                // there is a local definition defined
+                if ($defs[$attr_key] === false) {
+                    // We've explicitly been told not to allow this element.
+                    // This is usually when there's a global definition
+                    // that must be overridden.
+                    // Theoretically speaking, we could have a
+                    // AttrDef_DenyAll, but this is faster!
+                    $result = false;
+                } else {
+                    // validate according to the element's definition
+                    $result = $defs[$attr_key]->validate(
+                                    $value, $config, $context
+                               );
+                }
+            } elseif ( isset($d_defs[$attr_key]) ) {
+                // there is a global definition defined, validate according
+                // to the global definition
+                $result = $d_defs[$attr_key]->validate(
+                                $value, $config, $context
+                           );
+            } else {
+                // system never heard of the attribute? DELETE!
+                $result = false;
+            }
+            
+            // put the results into effect
+            if ($result === false || $result === null) {
+                // remove the attribute
+                unset($attr[$attr_key]);
+            } elseif (is_string($result)) {
+                // simple substitution
+                $attr[$attr_key] = $result;
+            }
+            
+            // we'd also want slightly more complicated substitution
+            // involving an array as the return value,
+            // although we're not sure how colliding attributes would
+            // resolve (certain ones would be completely overriden,
+            // others would prepend themselves).
+        }
+        
+        // post transforms
+        
+        // ex. <x lang="fr"> to <x lang="fr" xml:lang="fr">
+        foreach ($definition->info_attr_transform_post as $transform) {
+            $attr = $transform->transform($attr, $config, $context);
+        }
+        
+        // ex. <bdo> to <bdo dir="ltr">
+        foreach ($definition->info[$token->name]->attr_transform_post as $transform) {
+            $attr = $transform->transform($attr, $config, $context);
+        }
+        
+        // commit changes
+        $token->attr = $attr;
+        return $token;
+        
+    }
+    
+    
+}
+
+?>

library/HTMLPurifier/ElementDef.php

@@ -85,6 +85,13 @@ class HTMLPurifier_ElementDef
      */
     var $descendants_are_inline = false;
     
+    /**
+     * List of the names of required attributes this element has. Dynamically
+     * populated.
+     * @public
+     */
+    var $required_attr = array();
+    
     /**
      * Lookup table of tags excluded from all descendants of this tag.
      * @note SGML permits exclusions for all descendants, but this is
@@ -174,6 +181,13 @@ class HTMLPurifier_ElementDef
         }
     }
     
+    /**
+     * Retrieves a copy of the element definition
+     */
+    function copy() {
+        return unserialize(serialize($this));
+    }
+    
 }
 
 ?>

library/HTMLPurifier/HTMLModule/Image.php

@@ -19,13 +19,15 @@ class HTMLPurifier_HTMLModule_Image extends HTMLPurifier_HTMLModule
         $img =& $this->addElement(
             'img', true, 'Inline', 'Empty', 'Common',
             array(
-                'alt' => 'Text',
+                'alt*' => 'Text',
                 'height' => 'Length',
                 'longdesc' => 'URI', 
-                'src' => new HTMLPurifier_AttrDef_URI(true), // embedded
+                'src*' => new HTMLPurifier_AttrDef_URI(true), // embedded
                 'width' => 'Length'
             )
         );
+        // kind of strange, but splitting things up would be inefficient
+        $img->attr_transform_pre[] =
         $img->attr_transform_post[] =
             new HTMLPurifier_AttrTransform_ImgRequired();
     }

library/HTMLPurifier/HTMLModuleManager.php

@@ -405,7 +405,11 @@ class HTMLPurifier_HTMLModuleManager
         foreach($this->elementLookup[$name] as $module_name) {
             
             $module = $modules[$module_name];
-            $new_def = $module->info[$name];
+            
+            // copy is used because, ideally speaking, the original
+            // definition should not be modified. Usually, this will
+            // make no difference, but for consistency's sake
+            $new_def = $module->info[$name]->copy();
             
             // refuse to create/merge in a definition that is deemed unsafe
             if (!$trusted && ($new_def->safe === false)) {
@@ -444,6 +448,13 @@ class HTMLPurifier_HTMLModuleManager
             $this->contentSets->generateChildDef($def, $module);
         }
             
+        // add information on required attributes
+        foreach ($def->attr as $attr_name => $attr_def) {
+            if ($attr_def->required) {
+                $def->required_attr[] = $attr_name;
+            }
+        }
+        
         return $def;
         
     }

library/HTMLPurifier/Strategy/RemoveForeignElements.php

@@ -5,6 +5,8 @@ require_once 'HTMLPurifier/HTMLDefinition.php';
 require_once 'HTMLPurifier/Generator.php';
 require_once 'HTMLPurifier/TagTransform.php';
 
+require_once 'HTMLPurifier/AttrValidator.php';
+
 HTMLPurifier_ConfigSchema::define(
     'Core', 'RemoveInvalidImg', true, 'bool',
     'This directive enables pre-emptive URI checking in <code>img</code> '.
@@ -41,6 +43,8 @@ class HTMLPurifier_Strategy_RemoveForeignElements extends HTMLPurifier_Strategy
         $remove_invalid_img  = $config->get('Core', 'RemoveInvalidImg');
         $remove_script_contents = $config->get('Core', 'RemoveScriptContents');
         
+        $attr_validator = new HTMLPurifier_AttrValidator();
+        
         // removes tokens until it reaches a closing tag with its value
         $remove_until = false;
         
@@ -65,24 +69,23 @@ class HTMLPurifier_Strategy_RemoveForeignElements extends HTMLPurifier_Strategy
                 }
                 
                 if (isset($definition->info[$token->name])) {
-                    // leave untouched, except for a few special cases:
                     
-                    // hard-coded image special case, pre-emptively drop
-                    // if not available. Probably not abstract-able
-                    if ( $token->name == 'img' && $remove_invalid_img ) {
-                        if (!isset($token->attr['src'])) {
-                            continue;
+                    // mostly everything's good, but
+                    // we need to make sure required attributes are in order
+                    if (
+                        $definition->info[$token->name]->required_attr &&
+                        ($token->name != 'img' || $remove_invalid_img) // ensure config option still works
+                    ) {
+                        $token = $attr_validator->validateToken($token, $config, $context);
+                        $ok = true;
+                        foreach ($definition->info[$token->name]->required_attr as $name) {
+                            if (!isset($token->attr[$name])) {
+                                $ok = false;
+                                break;
+                            }
                         }
-                        if (!isset($definition->info['img']->attr['src'])) {
-                            continue;
-                        }
-                        $token->attr['src'] =
-                            $definition->
-                                info['img']->
-                                    attr['src']->
-                                        validate($token->attr['src'],
-                                            $config, $context);
-                        if ($token->attr['src'] === false) continue;
+                        if (!$ok) continue;
+                        $token->armor['ValidateAttributes'] = true;
                     }
                     
                 } elseif ($escape_invalid_tags) {

library/HTMLPurifier/Strategy/ValidateAttributes.php

@@ -4,6 +4,8 @@ require_once 'HTMLPurifier/Strategy.php';
 require_once 'HTMLPurifier/HTMLDefinition.php';
 require_once 'HTMLPurifier/IDAccumulator.php';
 
+require_once 'HTMLPurifier/AttrValidator.php';
+
 HTMLPurifier_ConfigSchema::define(
     'Attr', 'IDBlacklist', array(), 'list',
     'Array of IDs not allowed in the document.');
@@ -17,16 +19,13 @@ class HTMLPurifier_Strategy_ValidateAttributes extends HTMLPurifier_Strategy
     
     function execute($tokens, $config, &$context) {
         
-        $definition = $config->getHTMLDefinition();
-        
         // setup id_accumulator context
         $id_accumulator = new HTMLPurifier_IDAccumulator();
         $id_accumulator->load($config->get('Attr', 'IDBlacklist'));
         $context->register('IDAccumulator', $id_accumulator);
         
-        // create alias to global definition array, see also $defs
-        // DEFINITION CALL
-        $d_defs = $definition->info_global_attr;
+        // setup validator
+        $validator = new HTMLPurifier_AttrValidator();
         
         foreach ($tokens as $key => $token) {
             
@@ -34,91 +33,12 @@ class HTMLPurifier_Strategy_ValidateAttributes extends HTMLPurifier_Strategy
             //   namely start and empty tags
             if ($token->type !== 'start' && $token->type !== 'empty') continue;
             
-            // copy out attributes for easy manipulation
-            $attr = $token->attr;
+            // skip tokens that are armored
+            if (!empty($token->armor['ValidateAttributes'])) continue;
             
-            // do global transformations (pre)
-            // nothing currently utilizes this
-            foreach ($definition->info_attr_transform_pre as $transform) {
-                $attr = $transform->transform($attr, $config, $context);
-            }
-            
-            // do local transformations only applicable to this element (pre)
-            // ex. <p align="right"> to <p style="text-align:right;">
-            foreach ($definition->info[$token->name]->attr_transform_pre
-                as $transform
-            ) {
-                $attr = $transform->transform($attr, $config, $context);
-            }
-            
-            // create alias to this element's attribute definition array, see
-            // also $d_defs (global attribute definition array)
-            // DEFINITION CALL
-            $defs = $definition->info[$token->name]->attr;
-            
-            // iterate through all the attribute keypairs
-            // Watch out for name collisions: $key has previously been used
-            foreach ($attr as $attr_key => $value) {
-                
-                // call the definition
-                if ( isset($defs[$attr_key]) ) {
-                    // there is a local definition defined
-                    if ($defs[$attr_key] === false) {
-                        // We've explicitly been told not to allow this element.
-                        // This is usually when there's a global definition
-                        // that must be overridden.
-                        // Theoretically speaking, we could have a
-                        // AttrDef_DenyAll, but this is faster!
-                        $result = false;
-                    } else {
-                        // validate according to the element's definition
-                        $result = $defs[$attr_key]->validate(
-                                        $value, $config, $context
-                                   );
-                    }
-                } elseif ( isset($d_defs[$attr_key]) ) {
-                    // there is a global definition defined, validate according
-                    // to the global definition
-                    $result = $d_defs[$attr_key]->validate(
-                                    $value, $config, $context
-                               );
-                } else {
-                    // system never heard of the attribute? DELETE!
-                    $result = false;
-                }
-                
-                // put the results into effect
-                if ($result === false || $result === null) {
-                    // remove the attribute
-                    unset($attr[$attr_key]);
-                } elseif (is_string($result)) {
-                    // simple substitution
-                    $attr[$attr_key] = $result;
-                }
-                
-                // we'd also want slightly more complicated substitution
-                // involving an array as the return value,
-                // although we're not sure how colliding attributes would
-                // resolve (certain ones would be completely overriden,
-                // others would prepend themselves).
-            }
-            
-            // post transforms
-            
-            // ex. <x lang="fr"> to <x lang="fr" xml:lang="fr">
-            foreach ($definition->info_attr_transform_post as $transform) {
-                $attr = $transform->transform($attr, $config, $context);
-            }
-            
-            // ex. <bdo> to <bdo dir="ltr">
-            foreach ($definition->info[$token->name]->attr_transform_post as $transform) {
-                $attr = $transform->transform($attr, $config, $context);
-            }
-            
-            // commit changes
-            // could interfere with flyweight implementation
-            $tokens[$key]->attr = $attr;
+            $tokens[$key] = $validator->validateToken($token, $config, $context);
         }
+        
         $context->destroy('IDAccumulator');
         
         return $tokens;

library/HTMLPurifier/Token.php

@@ -13,6 +13,12 @@ class HTMLPurifier_Token {
     var $type; /**< Type of node to bypass <tt>is_a()</tt>. @public */
     var $line; /**< Line number node was on in source document. Null if unknown. @public */
     
+    /**
+     * Lookup array of processing that this token is exempt from.
+     * Currently, the only valid value is "ValidateAttributes".
+     */
+    var $armor = array();
+    
     /**
      * Copies the tag into a new one (clone substitute).
      * @return Copied token

maintenance/flush-htmldefinition-cache.php

@@ -2,7 +2,7 @@
 <?php
 
 /**
- * Flushes the HTMLDefinition serial cache
+ * Flushes the default HTMLDefinition serial cache
  */
 
 if (php_sapi_name() != 'cli') {
@@ -14,8 +14,10 @@ echo 'Flushing cache... ';
 
 require_once(dirname(__FILE__) . '/../library/HTMLPurifier.auto.php');
 
+$config = HTMLPurifier_Config::createDefault();
+
 $cache = new HTMLPurifier_DefinitionCache_Serializer('HTML');
-$cache->flush();
+$cache->flush($config);
 
 echo 'Cache flushed successfully.';
 

tests/HTMLPurifier/AttrCollectionsTest.php

@@ -110,17 +110,24 @@ class HTMLPurifier_AttrCollectionsTest extends UnitTestCase
         
         $attr = array(
             'attr1' => 'Color',
-            'attr2' => 'URI'
+            'attr2*' => 'URI'
         );
-        $types->setReturnValue('get', 'ColorObject', array('Color'));
-        $types->setReturnValue('get', 'URIObject', array('URI'));
+        $c_object = new HTMLPurifier_AttrDef();
+        $c_object->_name = 'Color'; // for testing purposes only
+        $u_object = new HTMLPurifier_AttrDef();
+        $u_object->_name = 'URL'; // for testing purposes only
+        
+        $types->setReturnValue('get', $c_object, array('Color'));
+        $types->setReturnValue('get', $u_object, array('URI'));
+        
         $collections->expandIdentifiers($attr, $types);
         
+        $u_object->required = true;
         $this->assertIdentical(
             $attr,
             array(
-                'attr1' => 'ColorObject',
-                'attr2' => 'URIObject'
+                'attr1' => $c_object,
+                'attr2' => $u_object
             )
         );
         

tests/HTMLPurifier/AttrTransform/ImgRequiredTest.php

@@ -15,7 +15,10 @@ class HTMLPurifier_AttrTransform_ImgRequiredTest extends HTMLPurifier_AttrTransf
         
         $this->assertResult(
             array(),
-            array('src' => '', 'alt' => 'Invalid image')
+            array('src' => '', 'alt' => 'Invalid image'),
+            array(
+                'Core.RemoveInvalidImg' => false
+            )
         );
         
         $this->assertResult(
@@ -23,7 +26,8 @@ class HTMLPurifier_AttrTransform_ImgRequiredTest extends HTMLPurifier_AttrTransf
             array('src' => 'blank.png', 'alt' => 'Pawned!'),
             array(
                 'Attr.DefaultInvalidImage' => 'blank.png',
-                'Attr.DefaultInvalidImageAlt' => 'Pawned!'
+                'Attr.DefaultInvalidImageAlt' => 'Pawned!',
+                'Core.RemoveInvalidImg' => false
             )
         );
         
@@ -34,7 +38,10 @@ class HTMLPurifier_AttrTransform_ImgRequiredTest extends HTMLPurifier_AttrTransf
         
         $this->assertResult(
             array('alt' => 'intrigue'),
-            array('alt' => 'intrigue', 'src' => '')
+            array('alt' => 'intrigue', 'src' => ''),
+            array(
+                'Core.RemoveInvalidImg' => false
+            )
         );
         
     }

tests/HTMLPurifier/HTMLModuleManagerTest.php

@@ -9,7 +9,8 @@ class HTMLPurifier_HTMLModuleManagerTest extends UnitTestCase
         $manager = new HTMLPurifier_HTMLModuleManager();
         $manager->doctypes->register('Blank'); // doctype normally is blank...
         
-        $attrdef_nmtokens = 1; // magic number
+        $attrdef_nmtokens = new HTMLPurifier_AttrDef();
+        $attrdef_nmtokens->_name = 'nmtokens'; // for testing only
         
         generate_mock_once('HTMLPurifier_AttrDef');
         $attrdef =& new HTMLPurifier_AttrDefMock($this);

tests/HTMLPurifier/Strategy/RemoveForeignElementsTest.php

@@ -61,7 +61,7 @@ class HTMLPurifier_Strategy_RemoveForeignElementsTest
         );
         
         // test preservation of valid img tag
-        $this->assertResult('<img src="foobar.gif" />');
+        $this->assertResult('<img src="foobar.gif" alt="foobar.gif" />');
         
         // test preservation of invalid img tag when removal is disabled
         $this->assertResult(

tests/HTMLPurifier/Strategy/ValidateAttributesTest.php

@@ -217,11 +217,10 @@ class HTMLPurifier_Strategy_ValidateAttributesTest extends
     }
     
     function testImg() {
-        // (this should never happen, as RemoveForeignElements
-        //  should have removed the offending image tag)
         $this->assertResult(
             '<img />',
-            '<img src="" alt="Invalid image" />'
+            '<img src="" alt="Invalid image" />',
+            array('Core.RemoveInvalidImg' => false)
         );
         
         $this->assertResult(
@@ -231,12 +230,14 @@ class HTMLPurifier_Strategy_ValidateAttributesTest extends
         
         $this->assertResult(
             '<img alt="pretty picture" />',
-            '<img alt="pretty picture" src="" />'
+            '<img alt="pretty picture" src="" />',
+            array('Core.RemoveInvalidImg' => false)
         );
         // mailto in image is not allowed
         $this->assertResult(
             '<img src="mailto:foo@example.com" />',
-            '<img src="" alt="Invalid image" />'
+            '<img alt="mailto:foo@example.com" src="" />',
+            array('Core.RemoveInvalidImg' => false)
         );
         // align transformation
         $this->assertResult(