[1.7.0] New compact syntax for AttrDef objects that can be used to instantiate new objects via make()

- Implemented make() for Enum and Bool
- Migrate classes over to this new syntax
- Add AttrDef_HTML_Bool unit test

git-svn-id: http://htmlpurifier.org/svnroot/htmlpurifier/trunk@1088 48356398-32a2-884e-a903-53898d9a118a

library/HTMLPurifier/AttrDef.php

@@ -62,6 +62,20 @@ class HTMLPurifier_AttrDef
         $string = str_replace(array("\r", "\t"), ' ', $string);
         return $string;
     }
+    
+    /**
+     * Factory method for creating this class from a string.
+     * @param $string String construction info
+     * @return Created AttrDef object corresponding to $string
+     * @public
+     */
+    function make($string) {
+        // default implementation, return flyweight of this object
+        // if overloaded, it is *necessary* for you to clone the
+        // object (usually by instantiating a new copy) and return that
+        return $this;
+    }
+    
 }
 
 ?>