Implement attribute transforms for required attributes. I can now confidently say that output will always be valid.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@256 48356398-32a2-884e-a903-53898d9a118a

docs/progress.html

@@ -80,7 +80,7 @@ thead th {text-align:left;padding:0.1em;background-color:#EEE;}
     <tr><td>DEL, INS</td><td>Link to explanation why it changed</td></tr>
 <tr><td>href</td><td>A</td><td>-</td></tr>
 <tr><td>longdesc</td><td>IMG</td><td>-</td></tr>
-<tr class="required impl-partial"><td>src</td><td>IMG</td><td>Required</td></tr>
+<tr class="required"><td>src</td><td>IMG</td><td>Required</td></tr>
 </tbody>
 
 <tbody>
@@ -90,14 +90,14 @@ thead th {text-align:left;padding:0.1em;background-color:#EEE;}
     <tr><td>TABLE</td></tr>
     <tr><td>HR</td><td>Equivalent style 'text-align' (IE tested)</td></tr>
     <tr class="impl-yes"><td>H1, H2, H3, H4, H5, H6, P</td><td>Equivalent style 'text-align'</td></tr>
-<tr class="required"><td>alt</td><td>IMG</td><td>Required, insert image filename if non-existant</td></tr>
+<tr class="required impl-yes"><td>alt</td><td>IMG</td><td>Required, insert image filename if src is present or default invalid image text</td></tr>
 <tr><td rowspan="3">bgcolor</td><td>TABLE</td><td>Equivalent style 'background-color' (IE tested)</td></tr>
     <tr><td>TR</td><td>Equivalent style 'background-color' (IE tested)</td></tr>
     <tr><td>TD, TH</td><td>Equivalent style 'background-color'</td></tr>
 <tr><td>border</td><td>IMG</td><td>Equivalent style 'border-width', only applies when link present</td></tr>
 <tr><td>clear</td><td>BR</td><td>Near-equiv style 'clear', transform 'all' into 'both'</td></tr>
 <tr class="impl-no"><td>compact</td><td>DL, OL, UL</td><td>Boolean, needs custom CSS class</td></tr>
-<tr class="required"><td>dir</td><td>BDO</td><td>Required, insert ltr (or configuration value) if none</td></tr>
+<tr class="required impl-yes"><td>dir</td><td>BDO</td><td>Required, insert ltr (or configuration value) if none</td></tr>
 <tr><td>height</td><td>TD, TH</td><td>Near-equiv style 'height', needs px suffix if original was in pixels</td></tr>
 <tr><td>hspace</td><td>IMG</td><td>Near-equiv styles 'margin-top' and 'margin-bottom', needs px suffix</td></tr>
 <tr class="impl-yes"><td>lang</td><td>*</td><td>Copy value to xml:lang</td></tr>
@@ -106,7 +106,7 @@ thead th {text-align:left;padding:0.1em;background-color:#EEE;}
 <tr><td>noshade</td><td>HR</td><td>Boolean, style 'border-style:solid;'</td></tr>
 <tr><td>nowrap</td><td>TD, TH</td><td>Boolean, style 'white-space:nowrap;' (not compat with IE5)</td></tr>
 <tr><td>size</td><td>HR</td><td>Near-equiv 'width', needs px suffix if original was pixels</td></tr>
-<tr class="required"><td>src</td><td>IMG</td><td>Required, insert blank or default img if not set</td></tr>
+<tr class="required impl-yes"><td>src</td><td>IMG</td><td>Required, insert blank or default img if not set</td></tr>
 <tr><td>start</td><td>OL</td><td>Poorly supported 'counter-reset', transform may not be desirable</td></tr>
 <tr><td rowspan="3">type</td><td>LI</td><td rowspan="3">Equivalent style 'list-style-type', different allowed values though. (needs testing)</td></tr>
     <tr><td>OL</td></tr>
@@ -168,7 +168,7 @@ thead th {text-align:left;padding:0.1em;background-color:#EEE;}
     decimal, lower-roman, upper-roman, lower-alpha and upper-alpha. See also
     CSS 3. Mostly IE lack of support.</td></tr>
 <tr class="css1"><td>list-style</td><td>SHORTHAND</td></tr>
-<tr class="css1"><td>margin</td><td>MULIPLE</td></tr>
+<tr class="css1"><td>margin</td><td>MULTIPLE</td></tr>
 <tr class="css1"><td>margin-*</td><td>COMPOSITE(&lt;length&gt;,
     &lt;percentage&gt;, auto)</td></tr>
 <tr class="css1"><td>padding</td><td>MULTIPLE</td></tr>

library/HTMLPurifier/AttrTransform/BdoDir.php

@@ -0,0 +1,25 @@
+<?php
+
+require_once 'HTMLPurifier/AttrTransform.php';
+
+// this MUST be placed in post, as it assumes that any value in dir is valid
+
+HTMLPurifier_ConfigDef::define(
+    'Attr', 'DefaultTextDir', 'ltr',
+    'Defines the default text direction (ltr or rtl) of the document '.
+    'being parsed.  This generally is the same as the value of the dir '.
+    'attribute in HTML, or ltr if that is not specified.'
+);
+
+class HTMLPurifier_AttrTransform_BdoDir extends HTMLPurifier_AttrTransform
+{
+    
+    function transform($attributes, $config) {
+        if (isset($attributes['dir'])) return $attributes;
+        $attributes['dir'] = $config->get('Attr', 'DefaultTextDir');
+        return $attributes;
+    }
+    
+}
+
+?>

library/HTMLPurifier/AttrTransform/ImgRequired.php

@@ -0,0 +1,47 @@
+<?php
+
+require_once 'HTMLPurifier/AttrTransform.php';
+
+// must be called POST validation
+
+HTMLPurifier_ConfigDef::define(
+    'Attr', 'DefaultInvalidImage', '',
+    'This is the default image an img tag will be pointed to if it does '.
+    'not have a valid src attribute.  In future versions, we may allow the '.
+    'image tag to be removed completely, but due to design issues, this is '.
+    'not possible right now.'
+);
+
+HTMLPurifier_ConfigDef::define(
+    'Attr', 'DefaultInvalidImageAlt', 'Invalid image',
+    'This is the content of the alt tag of an invalid image if the user '.
+    'had not previously specified an alt attribute.  It has no effect when the '.
+    'image is valid but there was no alt attribute present.'
+);
+
+class HTMLPurifier_AttrTransform_ImgRequired extends HTMLPurifier_AttrTransform
+{
+    
+    function transform($attributes, $config) {
+        
+        $src = true;
+        if (!isset($attributes['src'])) {
+            $attributes['src'] = $config->get('Attr', 'DefaultInvalidImage');
+            $src = false;
+        }
+        
+        if (!isset($attributes['alt'])) {
+            if ($src) {
+                $attributes['alt'] = basename($attributes['src']);
+            } else {
+                $attributes['alt'] = $config->get('Attr', 'DefaultInvalidImageAlt');
+            }
+        }
+        
+        return $attributes;
+        
+    }
+    
+}
+
+?>

library/HTMLPurifier/AttrTransform/Lang.php

@@ -2,10 +2,13 @@
 
 require_once 'HTMLPurifier/AttrTransform.php';
 
+// this transformation may be done pre or post validation, but post is
+// preferred, since invalid languages then will have been dropped.
+
 class HTMLPurifier_AttrTransform_Lang extends HTMLPurifier_AttrTransform
 {
     
-    function transform($attr) {
+    function transform($attr, $config) {
         
         $lang     = isset($attr['lang']) ? $attr['lang'] : false;
         $xml_lang = isset($attr['xml:lang']) ? $attr['xml:lang'] : false;

library/HTMLPurifier/AttrTransform/TextAlign.php

@@ -5,7 +5,7 @@ require_once 'HTMLPurifier/AttrTransform.php';
 class HTMLPurifier_AttrTransform_TextAlign
     extends HTMLPurifier_AttrTransform {
 
-    function transform($attr) {
+    function transform($attr, $config) {
         
         if (!isset($attr['align'])) return $attr;
         

library/HTMLPurifier/HTMLDefinition.php

@@ -15,6 +15,8 @@ require_once 'HTMLPurifier/AttrDef.php';
 require_once 'HTMLPurifier/AttrTransform.php';
     require_once 'HTMLPurifier/AttrTransform/Lang.php';
     require_once 'HTMLPurifier/AttrTransform/TextAlign.php';
+    require_once 'HTMLPurifier/AttrTransform/BdoDir.php';
+    require_once 'HTMLPurifier/AttrTransform/ImgRequired.php';
 require_once 'HTMLPurifier/ChildDef.php';
 require_once 'HTMLPurifier/Generator.php';
 require_once 'HTMLPurifier/Token.php';
@@ -56,7 +58,8 @@ class HTMLPurifier_HTMLDefinition
     var $info_tag_transform = array();
     
     // used solely by HTMLPurifier_Strategy_ValidateAttributes
-    var $info_attr_transform = array();
+    var $info_attr_transform_pre = array();
+    var $info_attr_transform_post = array();
     
     // WARNING! Prototype is not passed by reference, so in order to get
     // a copy of the real one, you'll have to destroy your copy and
@@ -350,23 +353,31 @@ class HTMLPurifier_HTMLDefinition
         // or we can just create another info
         
         //////////////////////////////////////////////////////////////////////
-        // info[]->attr_transform : attribute transformations in elements
+        // info[]->attr_transform_* : attribute transformations in elements
+        // pre is applied before any validation is done, post is done after
         
-        $transform = new HTMLPurifier_AttrTransform_TextAlign();
-        $this->info['h1']->attr_transform[] =
-        $this->info['h2']->attr_transform[] =
-        $this->info['h3']->attr_transform[] =
-        $this->info['h4']->attr_transform[] =
-        $this->info['h5']->attr_transform[] =
-        $this->info['h6']->attr_transform[] =
-        $this->info['p'] ->attr_transform[] = $transform;
+        $this->info['h1']->attr_transform_pre[] =
+        $this->info['h2']->attr_transform_pre[] =
+        $this->info['h3']->attr_transform_pre[] =
+        $this->info['h4']->attr_transform_pre[] =
+        $this->info['h5']->attr_transform_pre[] =
+        $this->info['h6']->attr_transform_pre[] =
+        $this->info['p'] ->attr_transform_pre[] = 
+                    new HTMLPurifier_AttrTransform_TextAlign();
+        
+        $this->info['bdo']->attr_transform_post[] =
+                    new HTMLPurifier_AttrTransform_BdoDir();
+        
+        $this->info['img']->attr_transform_post[] =
+                    new HTMLPurifier_AttrTransform_ImgRequired();
         
         //////////////////////////////////////////////////////////////////////
-        // info_attr_transform : global attribute transformation that is
+        // info_attr_transform_* : global attribute transformation that is
         // unconditionally called. Good for transformations that have complex
         // start conditions
+        // pre is applied before any validation is done, post is done after
         
-        $this->info_attr_transform[] = new HTMLPurifier_AttrTransform_Lang();
+        $this->info_attr_transform_post[] = new HTMLPurifier_AttrTransform_Lang();
         
     }
     
@@ -387,7 +398,8 @@ class HTMLPurifier_ElementDef
 {
     
     var $attr = array();
-    var $attr_transform = array();
+    var $attr_transform_pre = array();
+    var $attr_transform_post = array();
     var $auto_close = array();
     var $child;
     var $type = 'unknown';

library/HTMLPurifier/Strategy/ValidateAttributes.php

@@ -47,20 +47,20 @@ class HTMLPurifier_Strategy_ValidateAttributes extends HTMLPurifier_Strategy
             // copy out attributes for easy manipulation
             $attr = $token->attributes;
             
-            // do global transformations
+            // do global transformations (pre)
             // ex. <ELEMENT lang="fr"> to <ELEMENT lang="fr" xml:lang="fr">
             // DEFINITION CALL
-            foreach ($this->definition->info_attr_transform as $transform) {
-                $attr = $transform->transform($attr);
+            foreach ($this->definition->info_attr_transform_pre as $transform) {
+                $attr = $transform->transform($attr, $config);
             }
             
-            // do local transformations only applicable to this element
+            // do local transformations only applicable to this element (pre)
             // ex. <p align="right"> to <p style="text-align:right;">
             // DEFINITION CALL
-            foreach ($this->definition->info[$token->name]->attr_transform
+            foreach ($this->definition->info[$token->name]->attr_transform_pre
                 as $transform
             ) {
-                $attr = $transform->transform($attr);
+                $attr = $transform->transform($attr, $config);
             }
             
             // create alias to this element's attribute definition array, see
@@ -115,6 +115,14 @@ class HTMLPurifier_Strategy_ValidateAttributes extends HTMLPurifier_Strategy
                 // others would prepend themselves).
             }
             
+            // post transforms
+            foreach ($this->definition->info_attr_transform_post as $transform) {
+                $attr = $transform->transform($attr, $config);
+            }
+            foreach ($this->definition->info[$token->name]->attr_transform_post as $transform) {
+                $attr = $transform->transform($attr, $config);
+            }
+            
             // commit changes
             // could interfere with flyweight implementation
             $tokens[$key]->attributes = $attr;

tests/HTMLPurifier/AttrTransform/BdoDirTest.php

@@ -0,0 +1,36 @@
+<?php
+
+require_once 'HTMLPurifier/AttrTransform/BdoDir.php';
+
+class HTMLPurifier_AttrTransform_BdoDirTest extends HTMLPurifier_AttrTransformHarness
+{
+    
+    function test() {
+        
+        $this->transform = new HTMLPurifier_AttrTransform_BdoDir();
+        
+        $inputs = array();
+        $expect = array();
+        $config = array();
+        
+        // add dir
+        $inputs[0] = array();
+        $expect[0] = array('dir' => 'ltr');
+        
+        // leave existing dir alone
+        $inputs[1] = array('dir' => 'rtl');
+        $expect[1] = array('dir' => 'rtl');
+        
+        $config_rtl = HTMLPurifier_Config::createDefault();
+        $config_rtl->set('Attr', 'DefaultTextDir', 'rtl');
+        $inputs[2] = array();
+        $expect[2] = array('dir' => 'rtl');
+        $config[2] = $config_rtl;
+        
+        $this->assertTransform($inputs, $expect, $config);
+        
+    }
+    
+}
+
+?>

tests/HTMLPurifier/AttrTransform/ImgRequiredTest.php

@@ -0,0 +1,35 @@
+<?php
+
+require_once 'HTMLPurifier/AttrTransform/ImgRequired.php';
+
+class HTMLPurifier_AttrTransform_ImgRequiredTest extends HTMLPurifier_AttrTransformHarness
+{
+    
+    function test() {
+        
+        $this->transform = new HTMLPurifier_AttrTransform_ImgRequired();
+        
+        $inputs = $expect = $config = array();
+        
+        $inputs[0] = array();
+        $expect[0] = array('src' => '', 'alt' => 'Invalid image');
+        
+        $inputs[1] = array();
+        $expect[1] = array('src' => 'blank.png', 'alt' => 'Pawned!');
+        $config[1] = HTMLPurifier_Config::createDefault();
+        $config[1]->set('Attr', 'DefaultInvalidImage', 'blank.png');
+        $config[1]->set('Attr', 'DefaultInvalidImageAlt', 'Pawned!');
+        
+        $inputs[2] = array('src' => '/path/to/foobar.png');
+        $expect[2] = array('src' => '/path/to/foobar.png', 'alt' => 'foobar.png');
+        
+        $inputs[3] = array('alt' => 'intrigue');
+        $expect[3] = array('src' => '', 'alt' => 'intrigue');
+        
+        $this->assertTransform($inputs, $expect, $config);
+        
+    }
+    
+}
+
+?>

tests/HTMLPurifier/AttrTransformHarness.php

@@ -5,16 +5,15 @@ class HTMLPurifier_AttrTransformHarness extends UnitTestCase
     
     var $transform;
     
-    function assertTransform($inputs, $expect) {
+    function assertTransform($inputs, $expect, $config = array()) {
+        $default_config = HTMLPurifier_Config::createDefault();
         foreach ($inputs as $i => $input) {
-            $result = $this->transform->transform($input);
-            if ($expect[$i] === true) {
-                $this->assertEqual($input, $result, "Test $i: %s");
-            } else {
+            if (!isset($config[$i])) $config[$i] = $default_config;
+            $result = $this->transform->transform($input, $config[$i]);
+            if ($expect[$i] === true) $expect[$i] = $input;
             $this->assertEqual($expect[$i], $result, "Test $i: %s");
         }
     }
-    }
     
 }
 

tests/HTMLPurifier/Strategy/ValidateAttributesTest.php

@@ -12,6 +12,9 @@ class HTMLPurifier_Strategy_ValidateAttributesTest extends
         
         $strategy = new HTMLPurifier_Strategy_ValidateAttributes();
         
+        // attribute order is VERY fragile, perhaps we should define
+        // an ordering scheme!
+        
         $inputs = array();
         $expect = array();
         $config = array();
@@ -68,8 +71,9 @@ class HTMLPurifier_Strategy_ValidateAttributesTest extends
         $expect[12] = '<h1 style="text-align:center;">Centered Headline</h1>';
         
         // test table
-        $inputs[13] = <<<HTML
-<table frame="above" rules="rows" summary="A test table" border="2" cellpadding="5%" cellspacing="3" width="100%">
+        $inputs[13] = 
+        
+'<table frame="above" rules="rows" summary="A test table" border="2" cellpadding="5%" cellspacing="3" width="100%">
     <col align="right" width="4*" />
     <col charoff="5" align="char" width="1*" />
     <tr valign="top">
@@ -83,8 +87,8 @@ class HTMLPurifier_Strategy_ValidateAttributesTest extends
     <tr>
         <td colspan="2">Taken off the market</td>
     </tr>
-</table>
-HTML;
+</table>';
+        
         $expect[13] = $inputs[13];
         
         // test URI
@@ -95,6 +99,27 @@ HTML;
         $inputs[15] = '<a href="javascript:badstuff();">Google</a>';
         $expect[15] = '<a>Google</a>';
         
+        // test required attributes for img
+        $inputs[16] = '<img />';
+        $expect[16] = '<img src="" alt="Invalid image" />';
+        
+        $inputs[17] = '<img src="foobar.jpg" />';
+        $expect[17] = '<img src="foobar.jpg" alt="foobar.jpg" />';
+        
+        $inputs[18] = '<img alt="pretty picture" />';
+        $expect[18] = '<img alt="pretty picture" src="" />';
+        
+        // test required attributes for bdo
+        $inputs[19] = '<bdo>Go left.</bdo>';
+        $expect[19] = '<bdo dir="ltr">Go left.</bdo>';
+        
+        $inputs[20] = '<bdo dir="blahblah">Invalid value!</bdo>';
+        $expect[20] = '<bdo dir="ltr">Invalid value!</bdo>';
+        
+        // comparison check for test 20
+        $inputs[21] = '<span dir="blahblah">Invalid value!</span>';
+        $expect[21] = '<span>Invalid value!</span>';
+        
         $this->assertStrategyWorks($strategy, $inputs, $expect, $config);
         
     }

tests/index.php

@@ -74,6 +74,8 @@ $test_files[] = 'IDAccumulatorTest.php';
 $test_files[] = 'TagTransformTest.php';
 $test_files[] = 'AttrTransform/LangTest.php';
 $test_files[] = 'AttrTransform/TextAlignTest.php';
+$test_files[] = 'AttrTransform/BdoDirTest.php';
+$test_files[] = 'AttrTransform/ImgRequiredTest.php';
 $test_files[] = 'URISchemeRegistryTest.php';
 $test_files[] = 'URISchemeTest.php';