diff --git a/docs/config.txt b/docs/config.txt
index 800ea05d..0ac54c67 100644
--- a/docs/config.txt
+++ b/docs/config.txt
@@ -10,12 +10,9 @@ Directives are divided into namespaces, indicating the major portion of
 functionality they cover (although there may be overlaps.  Please consult
 the documentation in ConfigDef for more information on these namespaces.
 
-Since configuration is dependent on context, most of the internal classes
-require a configuration object to be passed as a parameter.  However, a few
-make this optional: they will supply a default configuration object if none
-are passed.  These classes are: HTMLPurifier::*, Generator::generateFromTokens
-and Lexer::tokenizeHTML.  However, whenever a valid configuration object
-is defined, that object should be used.
+Since configuration is dependant on context, internal classes require a
+configuration object to be passed as a parameter.  (They also require a
+Context object).
 
 In relation to HTMLDefinition and CSSDefinition, there is a special class
 of directives that influence the *construction* of the Definition object.
diff --git a/library/HTMLPurifier.php b/library/HTMLPurifier.php
index f02bf0c2..64028d6c 100644
--- a/library/HTMLPurifier.php
+++ b/library/HTMLPurifier.php
@@ -44,6 +44,7 @@
 // they get included
 require_once 'HTMLPurifier/ConfigSchema.php';
 require_once 'HTMLPurifier/Config.php';
+require_once 'HTMLPurifier/Context.php';
 
 require_once 'HTMLPurifier/Lexer.php';
 require_once 'HTMLPurifier/Generator.php';
@@ -95,16 +96,17 @@ class HTMLPurifier
      */
     function purify($html, $config = null) {
         $config = $config ? $config : $this->config;
-        $html = $this->encoder->convertToUTF8($html, $config);
+        $context =& new HTMLPurifier_Context();
+        $html = $this->encoder->convertToUTF8($html, $config, $context);
         $html = 
             $this->generator->generateFromTokens(
                 $this->strategy->execute(
-                    $this->lexer->tokenizeHTML($html, $config),
-                    $config
+                    $this->lexer->tokenizeHTML($html, $config, $context),
+                    $config, $context
                 ),
-                $config
+                $config, $context
             );
-        $html = $this->encoder->convertFromUTF8($html, $config);
+        $html = $this->encoder->convertFromUTF8($html, $config, $context);
         return $html;
     }
     
diff --git a/library/HTMLPurifier/ChildDef.php b/library/HTMLPurifier/ChildDef.php
index 793ec51a..19409b0d 100644
--- a/library/HTMLPurifier/ChildDef.php
+++ b/library/HTMLPurifier/ChildDef.php
@@ -38,15 +38,14 @@ class HTMLPurifier_ChildDef
     /**
      * Validates nodes according to definition and returns modification.
      * 
-     * @warning $context is NOT HTMLPurifier_AttrContext
      * @param $tokens_of_children Array of HTMLPurifier_Token
      * @param $config HTMLPurifier_Config object
-     * @param $context String context indicating inline, block or unknown
+     * @param $context HTMLPurifier_Context object
      * @return bool true to leave nodes as is
      * @return bool false to remove parent node
      * @return array of replacement child tokens
      */
-    function validateChildren($tokens_of_children, $config, $context) {
+    function validateChildren($tokens_of_children, $config, &$context) {
         trigger_error('Call to abstract function', E_USER_ERROR);
     }
 }
@@ -91,7 +90,7 @@ class HTMLPurifier_ChildDef_Custom extends HTMLPurifier_ChildDef
         $reg = preg_replace('/([#a-zA-Z0-9_.-]+)/', '(,?\\0)', $reg);
         $this->_pcre_regex = $reg;
     }
-    function validateChildren($tokens_of_children, $config, $context) {
+    function validateChildren($tokens_of_children, $config, &$context) {
         $list_of_children = '';
         $nesting = 0; // depth into the nest
         foreach ($tokens_of_children as $token) {
@@ -145,7 +144,7 @@ class HTMLPurifier_ChildDef_Required extends HTMLPurifier_ChildDef
     }
     var $allow_empty = false;
     var $type = 'required';
-    function validateChildren($tokens_of_children, $config, $context) {
+    function validateChildren($tokens_of_children, $config, &$context) {
         // if there are no tokens, delete parent node
         if (empty($tokens_of_children)) return false;
         
@@ -227,7 +226,7 @@ class HTMLPurifier_ChildDef_Optional extends HTMLPurifier_ChildDef_Required
 {
     var $allow_empty = true;
     var $type = 'optional';
-    function validateChildren($tokens_of_children, $config, $context) {
+    function validateChildren($tokens_of_children, $config, &$context) {
         $result = parent::validateChildren($tokens_of_children, $config, $context);
         if ($result === false) return array();
         return $result;
@@ -246,7 +245,7 @@ class HTMLPurifier_ChildDef_Empty extends HTMLPurifier_ChildDef
     var $allow_empty = true;
     var $type = 'empty';
     function HTMLPurifier_ChildDef_Empty() {}
-    function validateChildren($tokens_of_children, $config, $context) {
+    function validateChildren($tokens_of_children, $config, &$context) {
         return array();
     }
 }
@@ -281,8 +280,9 @@ class HTMLPurifier_ChildDef_Chameleon extends HTMLPurifier_ChildDef
         $this->block  = new HTMLPurifier_ChildDef_Optional($block);
     }
     
-    function validateChildren($tokens_of_children, $config, $context) {
-        switch ($context) {
+    function validateChildren($tokens_of_children, $config, &$context) {
+        $parent_type = $context->get('ParentType');
+        switch ($parent_type) {
             case 'unknown':
             case 'inline':
                 $result = $this->inline->validateChildren(
@@ -308,7 +308,7 @@ class HTMLPurifier_ChildDef_Table extends HTMLPurifier_ChildDef
     var $allow_empty = false;
     var $type = 'table';
     function HTMLPurifier_ChildDef_Table() {}
-    function validateChildren($tokens_of_children, $config, $context) {
+    function validateChildren($tokens_of_children, $config, &$context) {
         if (empty($tokens_of_children)) return false;
         
         // this ensures that the loop gets run one last time before closing
diff --git a/library/HTMLPurifier/Encoder.php b/library/HTMLPurifier/Encoder.php
index 9d7a35ef..ff4ea5af 100644
--- a/library/HTMLPurifier/Encoder.php
+++ b/library/HTMLPurifier/Encoder.php
@@ -266,7 +266,7 @@ class HTMLPurifier_Encoder
     /**
      * Converts a string to UTF-8 based on configuration.
      */
-    function convertToUTF8($str, $config) {
+    function convertToUTF8($str, $config, &$context) {
         static $iconv = null;
         if ($iconv === null) $iconv = function_exists('iconv');
         $encoding = $config->get('Core', 'Encoding');
@@ -283,7 +283,7 @@ class HTMLPurifier_Encoder
      * @note Currently, this is a lossy conversion, with unexpressable
      *       characters being omitted.
      */
-    function convertFromUTF8($str, $config) {
+    function convertFromUTF8($str, $config, &$context) {
         static $iconv = null;
         if ($iconv === null) $iconv = function_exists('iconv');
         $encoding = $config->get('Core', 'Encoding');
diff --git a/library/HTMLPurifier/Lexer.php b/library/HTMLPurifier/Lexer.php
index 962cb7bf..31d31d27 100644
--- a/library/HTMLPurifier/Lexer.php
+++ b/library/HTMLPurifier/Lexer.php
@@ -122,7 +122,7 @@ class HTMLPurifier_Lexer
      * @param $string String HTML.
      * @return HTMLPurifier_Token array representation of HTML.
      */
-    function tokenizeHTML($string, $config = null) {
+    function tokenizeHTML($string, $config, &$context) {
         trigger_error('Call to abstract class', E_USER_ERROR);
     }
     
@@ -196,7 +196,7 @@ class HTMLPurifier_Lexer
      * Takes a piece of HTML and normalizes it by converting entities, fixing
      * encoding, extracting bits, and other good stuff.
      */
-    function normalize($html, $config) {
+    function normalize($html, $config, &$context) {
         
         // extract body from document if applicable
         if ($config->get('Core', 'AcceptFullDocuments')) {
diff --git a/library/HTMLPurifier/Lexer/DOMLex.php b/library/HTMLPurifier/Lexer/DOMLex.php
index fbdecb8f..57720457 100644
--- a/library/HTMLPurifier/Lexer/DOMLex.php
+++ b/library/HTMLPurifier/Lexer/DOMLex.php
@@ -38,10 +38,9 @@ class HTMLPurifier_Lexer_DOMLex extends HTMLPurifier_Lexer
         $this->factory = new HTMLPurifier_TokenFactory();
     }
     
-    public function tokenizeHTML($string, $config = null) {
-        if (!$config) $config = HTMLPurifier_Config::createDefault();
+    public function tokenizeHTML($string, $config, &$context) {
         
-        $string = $this->normalize($string, $config);
+        $string = $this->normalize($string, $config, $context);
         
         // preprocess string, essential for UTF-8
         $string =
diff --git a/library/HTMLPurifier/Lexer/DirectLex.php b/library/HTMLPurifier/Lexer/DirectLex.php
index 4b9bff1e..30b56ba0 100644
--- a/library/HTMLPurifier/Lexer/DirectLex.php
+++ b/library/HTMLPurifier/Lexer/DirectLex.php
@@ -24,11 +24,9 @@ class HTMLPurifier_Lexer_DirectLex extends HTMLPurifier_Lexer
      */
     var $_whitespace = "\x20\x09\x0D\x0A";
     
-    function tokenizeHTML($html, $config = null) {
+    function tokenizeHTML($html, $config, &$context) {
         
-        if (!$config) $config = HTMLPurifier_Config::createDefault();
-        
-        $html = $this->normalize($html, $config);
+        $html = $this->normalize($html, $config, $context);
         
         $cursor = 0; // our location in the text
         $inside_tag = false; // whether or not we're parsing the inside of a tag
@@ -147,6 +145,7 @@ class HTMLPurifier_Lexer_DirectLex extends HTMLPurifier_Lexer
                 if ($attribute_string) {
                     $attributes = $this->parseAttributeString(
                                         $attribute_string
+                                      , $config, $context
                                   );
                 } else {
                     $attributes = array();
@@ -181,7 +180,7 @@ class HTMLPurifier_Lexer_DirectLex extends HTMLPurifier_Lexer
      * @param $string Inside of tag excluding name.
      * @returns Assoc array of attributes.
      */
-    function parseAttributeString($string) {
+    function parseAttributeString($string, $config, &$context) {
         $string = (string) $string; // quick typecast
         
         if ($string == '') return array(); // no attributes
diff --git a/library/HTMLPurifier/Lexer/PEARSax3.php b/library/HTMLPurifier/Lexer/PEARSax3.php
index 229b4636..ccd201a7 100644
--- a/library/HTMLPurifier/Lexer/PEARSax3.php
+++ b/library/HTMLPurifier/Lexer/PEARSax3.php
@@ -31,12 +31,11 @@ class HTMLPurifier_Lexer_PEARSax3 extends HTMLPurifier_Lexer
      */
     var $tokens = array();
     
-    function tokenizeHTML($string, $config = null) {
+    function tokenizeHTML($string, $config, &$context) {
         
         $this->tokens = array();
         
-        if (!$config) $config = HTMLPurifier_Config::createDefault();
-        $string = $this->normalize($string, $config);
+        $string = $this->normalize($string, $config, $context);
         
         $parser=& new XML_HTMLSax3();
         $parser->set_object($this);
diff --git a/library/HTMLPurifier/Strategy.php b/library/HTMLPurifier/Strategy.php
index 5632eb86..746b0a2d 100644
--- a/library/HTMLPurifier/Strategy.php
+++ b/library/HTMLPurifier/Strategy.php
@@ -24,7 +24,7 @@ class HTMLPurifier_Strategy
      * @param $config Configuration options
      * @returns Processed array of token objects.
      */
-    function execute($tokens, $config = null) {
+    function execute($tokens, $config, &$context) {
         trigger_error('Cannot call abstract function', E_USER_ERROR);
     }
     
diff --git a/library/HTMLPurifier/Strategy/Composite.php b/library/HTMLPurifier/Strategy/Composite.php
index 9e80e645..bd868747 100644
--- a/library/HTMLPurifier/Strategy/Composite.php
+++ b/library/HTMLPurifier/Strategy/Composite.php
@@ -18,9 +18,9 @@ class HTMLPurifier_Strategy_Composite extends HTMLPurifier_Strategy
         trigger_error('Attempt to instantiate abstract object', E_USER_ERROR);
     }
     
-    function execute($tokens, $config) {
+    function execute($tokens, $config, &$context) {
         foreach ($this->strategies as $strategy) {
-            $tokens = $strategy->execute($tokens, $config);
+            $tokens = $strategy->execute($tokens, $config, $context);
         }
         return $tokens;
     }
diff --git a/library/HTMLPurifier/Strategy/FixNesting.php b/library/HTMLPurifier/Strategy/FixNesting.php
index 18eb60b5..ca6f1a33 100644
--- a/library/HTMLPurifier/Strategy/FixNesting.php
+++ b/library/HTMLPurifier/Strategy/FixNesting.php
@@ -34,8 +34,7 @@ require_once 'HTMLPurifier/HTMLDefinition.php';
 class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy
 {
     
-    function execute($tokens, $config) {
-        
+    function execute($tokens, $config, &$context) {
         //####################################################################//
         // Pre-processing
         
@@ -49,6 +48,10 @@ class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy
         array_unshift($tokens, new HTMLPurifier_Token_Start($parent_name));
         $tokens[] = new HTMLPurifier_Token_End($parent_name);
         
+        // setup the context variables
+        $parent_type = 'unknown'; // reference var that we alter
+        $context->register('ParentType', $parent_type);
+        
         //####################################################################//
         // Loop initialization
         
@@ -109,10 +112,10 @@ class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy
             
             // calculate context
             if (isset($parent_def)) {
-                $context = $parent_def->type;
+                $parent_type = $parent_def->type;
             } else {
                 // generally found in specialized elements like UL
-                $context = 'unknown';
+                $parent_type = 'unknown';
             }
             
             //################################################################//
@@ -145,7 +148,7 @@ class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy
                 
                 // have DTD child def validate children
                 $result = $child_def->validateChildren(
-                    $child_tokens, $config,$context);
+                    $child_tokens, $config, $context);
                 
                 // determine whether or not this element has any exclusions
                 $excludes = $def->excludes;
@@ -247,6 +250,9 @@ class HTMLPurifier_Strategy_FixNesting extends HTMLPurifier_Strategy
         array_shift($tokens);
         array_pop($tokens);
         
+        // remove context variables
+        $context->destroy('ParentType');
+        
         //####################################################################//
         // Return
         
diff --git a/library/HTMLPurifier/Strategy/MakeWellFormed.php b/library/HTMLPurifier/Strategy/MakeWellFormed.php
index d82205bb..52243767 100644
--- a/library/HTMLPurifier/Strategy/MakeWellFormed.php
+++ b/library/HTMLPurifier/Strategy/MakeWellFormed.php
@@ -10,7 +10,7 @@ require_once 'HTMLPurifier/Generator.php';
 class HTMLPurifier_Strategy_MakeWellFormed extends HTMLPurifier_Strategy
 {
     
-    function execute($tokens, $config) {
+    function execute($tokens, $config, &$context) {
         $definition = $config->getHTMLDefinition();
         $generator = new HTMLPurifier_Generator();
         $result = array();
@@ -86,7 +86,7 @@ class HTMLPurifier_Strategy_MakeWellFormed extends HTMLPurifier_Strategy
             if (empty($current_nesting)) {
                 if ($escape_invalid_tags) {
                     $result[] = new HTMLPurifier_Token_Text(
-                        $generator->generateFromToken($token, $config)
+                        $generator->generateFromToken($token, $config, $context)
                     );
                 }
                 continue;
@@ -123,7 +123,7 @@ class HTMLPurifier_Strategy_MakeWellFormed extends HTMLPurifier_Strategy
             if ($skipped_tags === false) {
                 if ($escape_invalid_tags) {
                     $result[] = new HTMLPurifier_Token_Text(
-                        $generator->generateFromToken($token, $config)
+                        $generator->generateFromToken($token, $config, $context)
                     );
                 }
                 continue;
diff --git a/library/HTMLPurifier/Strategy/RemoveForeignElements.php b/library/HTMLPurifier/Strategy/RemoveForeignElements.php
index 1d9f7ae5..69976b27 100644
--- a/library/HTMLPurifier/Strategy/RemoveForeignElements.php
+++ b/library/HTMLPurifier/Strategy/RemoveForeignElements.php
@@ -16,7 +16,7 @@ require_once 'HTMLPurifier/TagTransform.php';
 class HTMLPurifier_Strategy_RemoveForeignElements extends HTMLPurifier_Strategy
 {
     
-    function execute($tokens, $config) {
+    function execute($tokens, $config, &$context) {
         $definition = $config->getHTMLDefinition();
         $generator = new HTMLPurifier_Generator();
         $result = array();
@@ -37,7 +37,7 @@ class HTMLPurifier_Strategy_RemoveForeignElements extends HTMLPurifier_Strategy
                 } elseif ($escape_invalid_tags) {
                     // invalid tag, generate HTML and insert in
                     $token = new HTMLPurifier_Token_Text(
-                        $generator->generateFromToken($token, $config)
+                        $generator->generateFromToken($token, $config, $context)
                     );
                 } else {
                     continue;
diff --git a/library/HTMLPurifier/Strategy/ValidateAttributes.php b/library/HTMLPurifier/Strategy/ValidateAttributes.php
index 3d3dec91..c4cd02b8 100644
--- a/library/HTMLPurifier/Strategy/ValidateAttributes.php
+++ b/library/HTMLPurifier/Strategy/ValidateAttributes.php
@@ -17,18 +17,18 @@ HTMLPurifier_ConfigSchema::define(
 class HTMLPurifier_Strategy_ValidateAttributes extends HTMLPurifier_Strategy
 {
     
-    function execute($tokens, $config) {
+    function execute($tokens, $config, &$context) {
         
         $definition = $config->getHTMLDefinition();
         
         // setup StrategyContext
-        $context = new HTMLPurifier_AttrContext();
+        $attr_context = new HTMLPurifier_AttrContext();
         
         // setup ID accumulator and load it with blacklisted IDs
         //     eventually, we'll have a dedicated context object to hold
         //     all these accumulators and caches. For now, just an IDAccumulator
-        $context->id_accumulator = new HTMLPurifier_IDAccumulator();
-        $context->id_accumulator->load($config->get('Attr', 'IDBlacklist'));
+        $attr_context->id_accumulator = new HTMLPurifier_IDAccumulator();
+        $attr_context->id_accumulator->load($config->get('Attr', 'IDBlacklist'));
         
         // create alias to global definition array, see also $defs
         // DEFINITION CALL
@@ -81,14 +81,14 @@ class HTMLPurifier_Strategy_ValidateAttributes extends HTMLPurifier_Strategy
                     } else {
                         // validate according to the element's definition
                         $result = $defs[$attr_key]->validate(
-                                        $value, $config, $context
+                                        $value, $config, $attr_context
                                    );
                     }
                 } elseif ( isset($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
+                                    $value, $config, $attr_context
                                );
                 } else {
                     // system never heard of the attribute? DELETE!
diff --git a/tests/HTMLPurifier/ChildDefTest.php b/tests/HTMLPurifier/ChildDefTest.php
index db00bd20..fed88ecf 100644
--- a/tests/HTMLPurifier/ChildDefTest.php
+++ b/tests/HTMLPurifier/ChildDefTest.php
@@ -1,122 +1,78 @@
 <?php
 
+require_once 'HTMLPurifier/Harness.php';
+
 require_once 'HTMLPurifier/ChildDef.php';
 require_once 'HTMLPurifier/Lexer/DirectLex.php';
 require_once 'HTMLPurifier/Generator.php';
 
-class HTMLPurifier_ChildDefTest extends UnitTestCase
+class HTMLPurifier_ChildDefTest extends HTMLPurifier_Harness
 {
     
-    var $def;
-    var $lex;
-    var $gen;
-    
-    function HTMLPurifier_ChildDefTest() {
-        // it is vital that the tags be treated as literally as possible
-        $this->lex = new HTMLPurifier_Lexer_DirectLex();
-        $this->gen = new HTMLPurifier_Generator();
-        parent::UnitTestCase();
-    }
-    
-    function assertSeries($inputs, $expect, $config, $context = array()) {
-        foreach ($inputs as $i => $input) {
-            
-            if (!isset($context[$i])) {
-                $context[$i] = null;
-            }
-            if (!isset($config[$i])) {
-                $config[$i] = HTMLPurifier_Config::createDefault();
-            }
-            
-            $tokens = $this->lex->tokenizeHTML($input, $config[$i]);
-            $result = $this->def->validateChildren($tokens, $config[$i], $context[$i]);
-            
-            if (is_bool($expect[$i])) {
-                $this->assertIdentical($expect[$i], $result, "Test $i: %s");
-            } else {
-                $result_html = $this->gen->generateFromTokens($result, $config[$i]);
-                $this->assertIdentical($expect[$i], $result_html, "Test $i: %s");
-                paintIf($result_html, $result_html != $expect[$i]);
-            }
-        }
+    function setUp() {
+        $this->obj       = null;
+        $this->func      = 'validateChildren';
+        $this->to_tokens = true;
+        $this->to_html   = true;
     }
     
     function test_custom() {
         
-        $this->def = new HTMLPurifier_ChildDef_Custom(
-            '(a, b?, c*, d+, (a, b)*)');
+        $this->obj = new HTMLPurifier_ChildDef_Custom('(a,b?,c*,d+,(a,b)*)');
         
-        $inputs = array();
-        $expect = array();
-        $config = array();
+        $this->assertResult('', false);
+        $this->assertResult('<a /><a />', false);
         
-        $inputs[0] = '';
-        $expect[0] = false;
+        $this->assertResult('<a /><b /><c /><d /><a /><b />');
+        $this->assertResult('<a /><d>Dob</d><a /><b>foo</b>'.
+          '<a href="moo" /><b>foo</b>');
         
-        $inputs[1] = '<a /><b /><c /><d /><a /><b />';
-        $expect[1] = true;
-        
-        $inputs[2] = '<a /><d>Dob</d><a /><b>foo</b><a href="moo" /><b>foo</b>';
-        $expect[2] = true;
-        
-        $inputs[3] = '<a /><a />';
-        $expect[3] = false;
-        
-        $this->assertSeries($inputs, $expect, $config);
     }
     
     function test_table() {
         
-        // currently inactive, awaiting augmentation
-        
         // the table definition
-        $this->def = new HTMLPurifier_ChildDef_Table();
+        $this->obj = new HTMLPurifier_ChildDef_Table();
         
         $inputs = $expect = $config = array();
         
-        $inputs[0] = '';
-        $expect[0] = false;
+        $this->assertResult('', false);
         
         // we're using empty tags to compact the tests: under real circumstances
         // there would be contents in them
         
-        $inputs[1] = '<tr />';
-        $expect[1] = true;
-        
-        $inputs[2] = '<caption /><col /><thead /><tfoot /><tbody>'.
-            '<tr><td>asdf</td></tr></tbody>';
-        $expect[2] = true;
-        
-        $inputs[3] = '<col /><col /><col /><tr />';
-        $expect[3] = true;
+        $this->assertResult('<tr />');
+        $this->assertResult('<caption /><col /><thead /><tfoot /><tbody>'.
+            '<tr><td>asdf</td></tr></tbody>');
+        $this->assertResult('<col /><col /><col /><tr />');
         
         // mixed up order
-        $inputs[4] = '<col /><colgroup /><tbody /><tfoot /><thead /><tr>1</tr><caption /><tr />';
-        $expect[4] = '<caption /><col /><colgroup /><thead /><tfoot /><tbody /><tr>1</tr><tr />';
+        $this->assertResult(
+          '<col /><colgroup /><tbody /><tfoot /><thead /><tr>1</tr><caption /><tr />',
+          '<caption /><col /><colgroup /><thead /><tfoot /><tbody /><tr>1</tr><tr />');
         
         // duplicates of singles
         // - first caption serves
         // - trailing tfoots/theads get turned into tbodys
-        $inputs[5] = '<caption>1</caption><caption /><tbody /><tbody /><tfoot>1</tfoot><tfoot />';
-        $expect[5] = '<caption>1</caption><tfoot>1</tfoot><tbody /><tbody /><tbody />';
+        $this->assertResult(
+          '<caption>1</caption><caption /><tbody /><tbody /><tfoot>1</tfoot><tfoot />',
+          '<caption>1</caption><tfoot>1</tfoot><tbody /><tbody /><tbody />'
+        );
         
         // errant text dropped (until bubbling is implemented)
-        $inputs[6] = 'foo';
-        $expect[6] = false;
+        $this->assertResult('foo', false);
         
         // whitespace sticks to the previous element, last whitespace is
         // stationary
-        $inputs[7] = "\n   <tr />\n  <tr />\n ";
-        $expect[7] = true;
-        
-        $inputs[8] = "\n\t<tbody />\n\t\t<tfoot />\n\t\t\t";
-        $expect[8] = "\n\t\t<tfoot />\n\t<tbody />\n\t\t\t";
-        
-        $this->assertSeries($inputs, $expect, $config);
+        $this->assertResult("\n   <tr />\n  <tr />\n ");
+        $this->assertResult(
+          "\n\t<tbody />\n\t\t<tfoot />\n\t\t\t",
+          "\n\t\t<tfoot />\n\t<tbody />\n\t\t\t"
+        );
         
     }
     
-    function test_parsing() {
+    function testParsing() {
         
         $def = new HTMLPurifier_ChildDef_Required('foobar | bang |gizmo');
         $this->assertEqual($def->elements,
@@ -132,92 +88,78 @@ class HTMLPurifier_ChildDefTest extends UnitTestCase
             'href' => true
            ,'src'  => true
           ));
+        
     }
     
     function test_required_pcdata_forbidden() {
         
-        $this->def = new HTMLPurifier_ChildDef_Required('dt | dd');
-        $inputs = $expect = $config = array();
+        $this->obj = new HTMLPurifier_ChildDef_Required('dt | dd');
         
-        $inputs[0] = '';
-        $expect[0] = false;
-        
-        $inputs[1] = '<dt>Term</dt>Text in an illegal location'.
-                     '<dd>Definition</dd><b>Illegal tag</b>';
-        
-        $expect[1] = '<dt>Term</dt><dd>Definition</dd>';
-        
-        $inputs[2] = 'How do you do!';
-        $expect[2] = false;
+        $this->assertResult('', false);
+        $this->assertResult(
+          '<dt>Term</dt>Text in an illegal location'.
+             '<dd>Definition</dd><b>Illegal tag</b>',
+          '<dt>Term</dt><dd>Definition</dd>');
+        $this->assertResult('How do you do!', false);
         
         // whitespace shouldn't trigger it
-        $inputs[3] = "\n<dd>Definition</dd>       ";
-        $expect[3] = true;
+        $this->assertResult("\n<dd>Definition</dd>       ");
         
-        $inputs[4] ='<dd>Definition</dd>       <b></b>       ';
-        $expect[4] = '<dd>Definition</dd>              ';
-        
-        $inputs[5] = "\t      ";
-        $expect[5] = false;
-        
-        $this->assertSeries($inputs, $expect, $config);
+        $this->assertResult(
+          '<dd>Definition</dd>       <b></b>       ',
+          '<dd>Definition</dd>              '
+        );
+        $this->assertResult("\t      ", false);
         
     }
     
     function test_required_pcdata_allowed() {
-        $this->def = new HTMLPurifier_ChildDef_Required('#PCDATA | b');
         
-        $inputs = $expect = $config = array();
+        $this->obj = new HTMLPurifier_ChildDef_Required('#PCDATA | b');
         
-        $inputs[0] = '<b>Bold text</b><img />';
-        $expect[0] = '<b>Bold text</b>';
+        $this->assertResult('<b>Bold text</b><img />', '<b>Bold text</b>');
         
         // with child escaping on
-        $inputs[1] = '<b>Bold text</b><img />';
-        $expect[1] = '<b>Bold text</b>&lt;img /&gt;';
-        $config[1] = HTMLPurifier_Config::createDefault();
-        $config[1]->set('Core', 'EscapeInvalidChildren', true);
+        $this->assertResult(
+            '<b>Bold text</b><img />',
+            '<b>Bold text</b>&lt;img /&gt;',
+            array(
+              'Core.EscapeInvalidChildren' => true
+            )
+        );
         
-        $this->assertSeries($inputs, $expect, $config);
     }
     
     function test_optional() {
-        $this->def = new HTMLPurifier_ChildDef_Optional('b | i');
         
-        $inputs = $expect = $config = array();
+        $this->obj = new HTMLPurifier_ChildDef_Optional('b | i');
         
-        $inputs[0] = '<b>Bold text</b><img />';
-        $expect[0] = '<b>Bold text</b>';
+        $this->assertResult('<b>Bold text</b><img />', '<b>Bold text</b>');
+        $this->assertResult('Not allowed text', '');
         
-        $inputs[1] = 'Not allowed text';
-        $expect[1] = '';
-        
-        $this->assertSeries($inputs, $expect, $config);
     }
     
     function test_chameleon() {
         
-        $this->def = new HTMLPurifier_ChildDef_Chameleon(
-            'b | i', // allowed only when in inline context
+        $this->obj = new HTMLPurifier_ChildDef_Chameleon(
+            'b | i',      // allowed only when in inline context
             'b | i | div' // allowed only when in block context
         );
         
-        $inputs = $expect = $config = array();
-        $context = array();
+        $this->assertResult(
+            '<b>Allowed.</b>', true,
+            array(), array('ParentType' => 'inline')
+        );
         
-        $inputs[0] = '<b>Allowed.</b>';
-        $expect[0] = true;
-        $context[0] = 'inline';
+        $this->assertResult(
+            '<div>Not allowed.</div>', '',
+            array(), array('ParentType' => 'inline')
+        );
         
-        $inputs[1] = '<div>Not allowed.</div>';
-        $expect[1] = '';
-        $context[1] = 'inline';
-        
-        $inputs[2] = '<div>Allowed.</div>';
-        $expect[2] = true;
-        $context[2] = 'block';
-        
-        $this->assertSeries($inputs, $expect, $config, $context);
+        $this->assertResult(
+            '<div>Allowed.</div>', true,
+            array(), array('ParentType' => 'block')
+        );
         
     }
     
diff --git a/tests/HTMLPurifier/EncoderTest.php b/tests/HTMLPurifier/EncoderTest.php
index 2ada77b2..2e0eae8d 100644
--- a/tests/HTMLPurifier/EncoderTest.php
+++ b/tests/HTMLPurifier/EncoderTest.php
@@ -31,10 +31,11 @@ class HTMLPurifier_EncoderTest extends UnitTestCase
     
     function test_convertToUTF8() {
         $config = HTMLPurifier_Config::createDefault();
+        $context = new HTMLPurifier_Context();
         
         // UTF-8 means that we don't touch it
         $this->assertIdentical(
-            $this->Encoder->convertToUTF8("\xF6", $config),
+            $this->Encoder->convertToUTF8("\xF6", $config, $context),
             "\xF6" // this is invalid
         );
         $this->assertNoErrors();
@@ -43,14 +44,14 @@ class HTMLPurifier_EncoderTest extends UnitTestCase
         
         // Now it gets converted
         $this->assertIdentical(
-            $this->Encoder->convertToUTF8("\xF6", $config),
+            $this->Encoder->convertToUTF8("\xF6", $config, $context),
             "\xC3\xB6"
         );
         
         $config->set('Test', 'ForceNoIconv', true);
         
         $this->assertIdentical(
-            $this->Encoder->convertToUTF8("\xF6", $config),
+            $this->Encoder->convertToUTF8("\xF6", $config, $context),
             "\xC3\xB6"
         );
         
@@ -58,10 +59,11 @@ class HTMLPurifier_EncoderTest extends UnitTestCase
     
     function test_convertFromUTF8() {
         $config = HTMLPurifier_Config::createDefault();
+        $context = new HTMLPurifier_Context();
         
         // UTF-8 means that we don't touch it
         $this->assertIdentical(
-            $this->Encoder->convertFromUTF8("\xC3\xB6", $config),
+            $this->Encoder->convertFromUTF8("\xC3\xB6", $config, $context),
             "\xC3\xB6"
         );
         
@@ -69,14 +71,14 @@ class HTMLPurifier_EncoderTest extends UnitTestCase
         
         // Now it gets converted
         $this->assertIdentical(
-            $this->Encoder->convertFromUTF8("\xC3\xB6", $config),
+            $this->Encoder->convertFromUTF8("\xC3\xB6", $config, $context),
             "\xF6"
         );
         
         $config->set('Test', 'ForceNoIconv', true);
         
         $this->assertIdentical(
-            $this->Encoder->convertFromUTF8("\xC3\xB6", $config),
+            $this->Encoder->convertFromUTF8("\xC3\xB6", $config, $context),
             "\xF6"
         );
         
diff --git a/tests/HTMLPurifier/Harness.php b/tests/HTMLPurifier/Harness.php
new file mode 100644
index 00000000..69c242f5
--- /dev/null
+++ b/tests/HTMLPurifier/Harness.php
@@ -0,0 +1,107 @@
+<?php
+
+/**
+ * General-purpose test-harness that makes testing functions that require
+ * configuration and context objects easier when those two parameters are
+ * meaningless.  See HTMLPurifier_ChildDefTest for a good example of usage.
+ */
+class HTMLPurifier_Harness extends UnitTestCase
+{
+    
+    /**
+     * Instance of the object that will execute the method
+     */
+    var $obj;
+    
+    /**
+     * Name of the function to be executed
+     */
+    var $func;
+    
+    /**
+     * Whether or not the method deals in tokens. If set to true, assertResult()
+     * will transparently convert HTML to and back from tokens.
+     */
+    var $to_tokens = false;
+    
+    /**
+     * Whether or not to convert tokens back into HTML before performing
+     * equality check, has no effect on bools.
+     */
+    var $to_html = false;
+    
+    /**
+     * Instance of an HTMLPurifier_Lexer implementation.
+     */
+    var $lexer;
+    
+    /**
+     * Instance of HTMLPurifier_Generator
+     */
+    var $generator;
+    
+    function HTMLPurifier_Harness() {
+        $this->lexer     = new HTMLPurifier_Lexer_DirectLex();
+        $this->generator = new HTMLPurifier_Generator();
+        parent::UnitTestCase();
+    }
+    
+    /**
+     * Asserts a specific result from a one parameter + config/context function
+     * @param $input Input parameter
+     * @param $expect Expectation
+     * @param $config_array Configuration array in form of
+     *                      Namespace.Directive => Value or an actual config
+     *                      object.
+     * @param $context_array Context array in form of Key => Value or an actual
+     *                       context object.
+     */
+    function assertResult($input, $expect = true,
+        $config_array = array(), $context_array = array()
+    ) {
+        
+        // setup config object
+        $config  = HTMLPurifier_Config::createDefault();
+        foreach ($config_array as $key => $value) {
+            list($namespace, $directive) = explode('.', $key);
+            $config->set($namespace, $directive, $value);
+        }
+        
+        // setup context object
+        $context = new HTMLPurifier_Context();
+        foreach ($context_array as $key => $value) {
+            $context->register($key, $value);
+        }
+        
+        if ($this->to_tokens && is_string($input)) {
+            $input = $this->lexer->tokenizeHTML($input, $config, $context);
+        }
+        
+        // call the function
+        $func = $this->func;
+        $result = $this->obj->$func($input, $config, $context);
+        
+        // test a bool result
+        if (is_bool($result)) {
+            $this->assertIdentical($expect, $result);
+            return;
+        } elseif (is_bool($expect)) {
+            $expect = $input;
+        }
+        
+        if ($this->to_html) {
+            $result = $this->generator->
+              generateFromTokens($result, $config, $context);
+            if (is_array($expect)) {
+                $expect = $this->generator->
+                  generateFromTokens($expect, $config, $context);
+            }
+        }
+        
+        $this->assertEqual($expect, $result);
+        
+    }
+    
+}
+
+?>
diff --git a/tests/HTMLPurifier/Lexer/DirectLexTest.php b/tests/HTMLPurifier/Lexer/DirectLexTest.php
index de35c1d1..4a2a0f16 100644
--- a/tests/HTMLPurifier/Lexer/DirectLexTest.php
+++ b/tests/HTMLPurifier/Lexer/DirectLexTest.php
@@ -53,9 +53,11 @@ class HTMLPurifier_Lexer_DirectLexTest extends UnitTestCase
         $input[10] = 'name="input" selected';
         $expect[10] = array('name' => 'input', 'selected' => 'selected');
         
+        $config = HTMLPurifier_Config::createDefault();
+        $context = new HTMLPurifier_Context();
         $size = count($input);
         for($i = 0; $i < $size; $i++) {
-            $result = $this->DirectLex->parseAttributeString($input[$i]);
+            $result = $this->DirectLex->parseAttributeString($input[$i], $config, $context);
             $this->assertEqual($expect[$i], $result, 'Test ' . $i . ': %s');
             paintIf($result, $expect[$i] != $result);
         }
diff --git a/tests/HTMLPurifier/LexerTest.php b/tests/HTMLPurifier/LexerTest.php
index 1ddc8a67..a690466b 100644
--- a/tests/HTMLPurifier/LexerTest.php
+++ b/tests/HTMLPurifier/LexerTest.php
@@ -279,16 +279,17 @@ class HTMLPurifier_LexerTest extends UnitTestCase
         $expect[18] = array( new HTMLPurifier_Token_Empty('br', array('test' => 'x < 6')) );
         
         $default_config = HTMLPurifier_Config::createDefault();
+        $default_context = new HTMLPurifier_Context();
         foreach($input as $i => $discard) {
             if (!isset($config[$i])) $config[$i] = $default_config;
             
-            $result = $this->DirectLex->tokenizeHTML($input[$i], $config[$i]);
+            $result = $this->DirectLex->tokenizeHTML($input[$i], $config[$i], $default_context);
             $this->assertEqual($expect[$i], $result, 'DirectLexTest '.$i.': %s');
             paintIf($result, $expect[$i] != $result);
             
             if ($this->_has_pear) {
                 // assert unless I say otherwise
-                $sax_result = $this->PEARSax3->tokenizeHTML($input[$i], $config[$i]);
+                $sax_result = $this->PEARSax3->tokenizeHTML($input[$i], $config[$i], $default_context);
                 if (!isset($sax_expect[$i])) {
                     // by default, assert with normal result
                     $this->assertEqual($expect[$i], $sax_result, 'PEARSax3Test '.$i.': %s');
@@ -304,7 +305,7 @@ class HTMLPurifier_LexerTest extends UnitTestCase
             }
             
             if ($this->_has_dom) {
-                $dom_result = $this->DOMLex->tokenizeHTML($input[$i], $config[$i]);
+                $dom_result = $this->DOMLex->tokenizeHTML($input[$i], $config[$i], $default_context);
                 // same structure as SAX
                 if (!isset($dom_expect[$i])) {
                     $this->assertEqual($expect[$i], $dom_result, 'DOMLexTest '.$i.': %s');
diff --git a/tests/HTMLPurifier/Strategy/CompositeTest.php b/tests/HTMLPurifier/Strategy/CompositeTest.php
index b557b201..d626d011 100644
--- a/tests/HTMLPurifier/Strategy/CompositeTest.php
+++ b/tests/HTMLPurifier/Strategy/CompositeTest.php
@@ -28,6 +28,7 @@ class HTMLPurifier_Strategy_CompositeTest extends UnitTestCase
         $mock_1 = new HTMLPurifier_StrategyMock($this);
         $mock_2 = new HTMLPurifier_StrategyMock($this);
         $mock_3 = new HTMLPurifier_StrategyMock($this);
+        $context = new HTMLPurifier_Context();
         
         // setup the object
         
@@ -43,9 +44,9 @@ class HTMLPurifier_Strategy_CompositeTest extends UnitTestCase
         
         $config = new HTMLPurifier_ConfigMock();
         
-        $params_1 = array($input_1, $config);
-        $params_2 = array($input_2, $config);
-        $params_3 = array($input_3, $config);
+        $params_1 = array($input_1, $config, $context);
+        $params_2 = array($input_2, $config, $context);
+        $params_3 = array($input_3, $config, $context);
         
         $mock_1->expectOnce('execute', $params_1);
         $mock_1->setReturnValue('execute', $input_2, $params_1);
@@ -58,7 +59,7 @@ class HTMLPurifier_Strategy_CompositeTest extends UnitTestCase
         
         // perform test
         
-        $output = $composite->execute($input_1, $config);
+        $output = $composite->execute($input_1, $config, $context);
         $this->assertIdentical($input_4, $output);
         
         // tally the calls
diff --git a/tests/HTMLPurifier/StrategyHarness.php b/tests/HTMLPurifier/StrategyHarness.php
index a39daf36..3ca07753 100644
--- a/tests/HTMLPurifier/StrategyHarness.php
+++ b/tests/HTMLPurifier/StrategyHarness.php
@@ -25,12 +25,13 @@ class HTMLPurifier_StrategyHarness extends UnitTestCase
     }
     
     function assertStrategyWorks($strategy, $inputs, $expect, $config = array()) {
+        $context = new HTMLPurifier_Context();
         foreach ($inputs as $i => $input) {
-            $tokens = $this->lex->tokenizeHTML($input);
             if (!isset($config[$i])) {
                 $config[$i] = HTMLPurifier_Config::createDefault();
             }
-            $result_tokens = $strategy->execute($tokens, $config[$i]);
+            $tokens = $this->lex->tokenizeHTML($input, $config[$i], $context);
+            $result_tokens = $strategy->execute($tokens, $config[$i], $context);
             $result = $this->gen->generateFromTokens($result_tokens, $config[$i]);
             $this->assertEqual($expect[$i], $result, "Test $i: %s");
             paintIf($result, $result != $expect[$i]);