From e08b5aaa704cc29f738f00524f211dc20fb6c5f1 Mon Sep 17 00:00:00 2001
From: "Edward Z. Yang" <edwardzyang@thewritingpot.com>
Date: Sat, 31 Mar 2007 03:41:22 +0000
Subject: [PATCH] [1.6.0] Add error messages for when user attempts to "allow"
 elements or attributes HTML Purifier does not support.

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@927 48356398-32a2-884e-a903-53898d9a118a
---
 NEWS                                    |  2 ++
 TODO                                    |  8 ++-----
 library/HTMLPurifier/HTMLDefinition.php | 31 +++++++++++++++++++++++++
 3 files changed, 35 insertions(+), 6 deletions(-)

diff --git a/NEWS b/NEWS
index 0a8b994f..2acd8f20 100644
--- a/NEWS
+++ b/NEWS
@@ -21,6 +21,8 @@ NEWS ( CHANGELOG and HISTORY )                                     HTMLPurifier
   and %Attr.AllowedRev to activate
 - You can define ID blacklists using regular expressions via
   %Attr.IDBlacklistRegexp
+- Error messages are emitted when you attempt to "allow" elements or
+  attributes that HTML Purifier does not support
 
 1.5.1, unknown release date
 - Fix segfault in unit test. The problem is not very reproduceable and
diff --git a/TODO b/TODO
index b6ce9930..9901a429 100644
--- a/TODO
+++ b/TODO
@@ -7,16 +7,12 @@ TODO List
     ? Maybe I'll Do It
 ==========================
 
-1.6 release [Long Overdue]
- - More user-friendly warnings when %HTML.Allow* attempts to specify a
-   tag or attribute that is not supported
-
 1.7 release [Advanced API]
  # Complete advanced API, and fully document it
- # Add pre-packaged "levels" of cleaning
  # Implement all edge-case attribute transforms
  # Implement all deprecated tags and attributes
- - Parse TinyMCE-style whitelist into our %HTML.Allow* whitelists
+ - Parse TinyMCE-style whitelist into our %HTML.Allow* whitelists (possibly
+   do this earlier)
 
 1.8 release [Refactor, refactor!]
  # URI validation routines tighter (see docs/dev-code-quality.html) (COMPLEX)
diff --git a/library/HTMLPurifier/HTMLDefinition.php b/library/HTMLPurifier/HTMLDefinition.php
index 6fca7fb7..e582b81a 100644
--- a/library/HTMLPurifier/HTMLDefinition.php
+++ b/library/HTMLPurifier/HTMLDefinition.php
@@ -218,18 +218,31 @@ class HTMLPurifier_HTMLDefinition
                 $this->info_parent, $this->config);
         }
         
+        // support template text
+        $support = "(for information on implementing this, see the ".
+                   "support forums) ";
+        
         // setup allowed elements, SubtractiveWhitelist module
         $allowed_elements = $this->config->get('HTML', 'AllowedElements');
         if (is_array($allowed_elements)) {
             foreach ($this->info as $name => $d) {
                 if(!isset($allowed_elements[$name])) unset($this->info[$name]);
+                unset($allowed_elements[$name]);
+            }
+            // emit errors
+            foreach ($allowed_elements as $element => $d) {
+                trigger_error("Element '$element' is not supported $support", E_USER_WARNING);
             }
         }
+        
         $allowed_attributes = $this->config->get('HTML', 'AllowedAttributes');
+        $allowed_attributes_mutable = $allowed_attributes; // by copy!
         if (is_array($allowed_attributes)) {
             foreach ($this->info_global_attr as $attr_key => $info) {
                 if (!isset($allowed_attributes["*.$attr_key"])) {
                     unset($this->info_global_attr[$attr_key]);
+                } elseif (isset($allowed_attributes_mutable["*.$attr_key"])) {
+                    unset($allowed_attributes_mutable["*.$attr_key"]);
                 }
             }
             foreach ($this->info as $tag => $info) {
@@ -237,9 +250,27 @@ class HTMLPurifier_HTMLDefinition
                     if (!isset($allowed_attributes["$tag.$attr"]) &&
                         !isset($allowed_attributes["*.$attr"])) {
                         unset($this->info[$tag]->attr[$attr]);
+                    } else {
+                        if (isset($allowed_attributes_mutable["$tag.$attr"])) {
+                            unset($allowed_attributes_mutable["$tag.$attr"]);
+                        } elseif (isset($allowed_attributes_mutable["*.$attr"])) {
+                            unset($allowed_attributes_mutable["*.$attr"]);
+                        }
                     }
                 }
             }
+            // emit errors
+            foreach ($allowed_attributes_mutable as $elattr => $d) {
+                list($element, $attribute) = explode('.', $elattr);
+                if ($element == '*') {
+                    trigger_error("Global attribute '$attribute' is not ".
+                        "supported in any elements $support",
+                        E_USER_WARNING);
+                } else {
+                    trigger_error("Attribute '$attribute' in element '$element' not supported $support",
+                        E_USER_WARNING);
+                }
+            }
         }
         
     }