[2.1.0] Friendly error messages for when injector needs a tag that's not allowed added

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1265 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/Injector/AutoParagraph.php

@@ -15,6 +15,11 @@ HTMLPurifier_ConfigSchema::define(
       block elements in nodes that allow paragraph tags</li>
   <li>There are double newlines in paragraph tags</li>
 </ul>
+<p>
+  <code>p</code> tags must be allowed for this directive to take effect.
+  We do not use <code>br</code> tags for paragraphing, as that is
+  semantically incorrect.
+</p>
 <p>
   This directive has been available since 2.0.1.
 </p>
@@ -27,6 +32,9 @@ HTMLPurifier_ConfigSchema::define(
 class HTMLPurifier_Injector_AutoParagraph extends HTMLPurifier_Injector
 {
     
+    var $name = 'AutoParagraph';
+    var $needed = array('p');
+    
     function _pStart() {
         $par = new HTMLPurifier_Token_Start('p');
         $par->armor['MakeWellFormed_TagClosedError'] = true;