Allowing DA to have an option connection hook which allows you to change the...

Allowing DA to have an option connection hook which allows you to change the database connection at run time for a sqlmethod.

lib/python/Shared/DC/ZRDB/DA.py

@@ -13,7 +13,7 @@
 __doc__='''Generic Database adapter'''
 
 
-__version__='$Revision: 1.105 $'[11:-2]
+__version__='$Revision: 1.106 $'[11:-2]
 
 import OFS.SimpleItem, Aqueduct, RDB, re
 import DocumentTemplate, marshal, md5, base64, Acquisition, os
@@ -74,6 +74,7 @@ class DA(
     _zclass=None
     allow_simple_one_argument_traversal=None
     template_class=SQL
+    connection_hook=None
 
     manage_options=(
         (
@@ -183,7 +184,7 @@ class DA(
 
     def manage_advanced(self, max_rows, max_cache, cache_time,
                         class_name, class_file, direct=None,
-                        REQUEST=None, zclass=''):
+                        REQUEST=None, zclass='', connection_hook=None):
         """Change advanced properties
 
         The arguments are:
@@ -230,6 +231,8 @@ class DA(
         self._v_brain=getBrain(self.class_file_, self.class_name_, 1)
         self.allow_simple_one_argument_traversal=direct
 
+        self.connection_hook = connection_hook
+
         if zclass:
             for d in self.aq_acquire('_getProductRegistryData')('zclasses'):
                 if ("%s/%s" % (d.get('product'),d.get('id'))) == zclass:
@@ -341,6 +344,10 @@ class DA(
     def _searchable_result_columns(self): return self._col
 
     def _cached_result(self, DB__, query):
+        pure_query = query
+        # we need to munge the incoming query key in the cache
+        # so that the same request to a different db is returned
+        query += '\nDBConnId: %s' % self.connection_hook
         
         # Try to fetch from cache
         if hasattr(self,'_v_cache'): cache=self._v_cache
@@ -364,7 +371,8 @@ class DA(
             k, r = cache[query]
             if k > t: return r
 
-        result=apply(DB__.query, query)
+        # call the pure query
+        result=apply(DB__.query, pure_query)
         if self.cache_time_ > 0:
             tcache[int(now)]=query
             cache[query]= now, result
@@ -389,11 +397,18 @@ class DA(
                 if hasattr(self, 'REQUEST'): REQUEST=self.REQUEST
                 else: REQUEST={}
 
-        try: dbc=getattr(self, self.connection_id)
+        # connection hook
+        c = self.connection_id
+        # for backwards compatability
+        hk = self.connection_hook
+        # go get the connection hook and call it
+        if hk: c = getattr(self, hk)()
+           
+        try: dbc=getattr(self, c)
         except AttributeError:
             raise AttributeError, (
                 "The database connection <em>%s</em> cannot be found." % (
-                self.connection_id))
+                c))
 
         try: DB__=dbc()
         except: raise 'Database Error', (

lib/python/Shared/DC/ZRDB/dtml/advanced.dtml

@@ -7,6 +7,19 @@
 <table cellspacing="0" cellpadding="2" border="0">
   	<tr>
     <td align="left" valign="top">
+    <div class="form-optional">
+    Connection Hook
+    </div>
+    </td>
+	  <td align="LEFT" valign="TOP">
+	    <input type="TEXT" name="connection_hook" size="40"
+                   value="<dtml-var connection_hook missing="" html_quote>">
+	  </td>
+	</tr>
+
+
+  <tr>
+    <td align="left" valign="top">
     <div class="form-label">
     Maximum rows to retrieve
     </div>