From: Mike Bayer <mike_mp@zzzcomputing.com>
Date: Wed, 2 May 2007 23:51:01 +0000 (+0000)
Subject: - Aliasizer removed.  hooray !
X-Git-Tag: rel_0_3_8~60
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=612c49f545b5374be45dbb4da21a5d708ebb894f;p=thirdparty%2Fsqlalchemy%2Fsqlalchemy.git

- Aliasizer removed.  hooray !
- ClauseVisitor has handy chain() method.
---

diff --git a/lib/sqlalchemy/orm/strategies.py b/lib/sqlalchemy/orm/strategies.py
index 4e5cf522d4..033d0cac14 100644
--- a/lib/sqlalchemy/orm/strategies.py
+++ b/lib/sqlalchemy/orm/strategies.py
@@ -363,27 +363,31 @@ class EagerLoader(AbstractRelationLoader):
             self.target = eagerloader.select_table
             self.eagertarget = eagerloader.select_table.alias(self._aliashash("/target"))
             self.extra_cols = {}
-            
+
             if eagerloader.secondary:
                 self.eagersecondary = eagerloader.secondary.alias(self._aliashash("/secondary"))
-                self.aliasizer = sql_util.Aliasizer(eagerloader.target, eagerloader.secondary, aliases={
-                        eagerloader.target:self.eagertarget,
-                        eagerloader.secondary:self.eagersecondary
-                        })
+                if parentclauses is not None:
+                    aliasizer = sql_util.ClauseAdapter(self.eagertarget).\
+                            chain(sql_util.ClauseAdapter(self.eagersecondary)).\
+                            chain(sql_util.ClauseAdapter(parentclauses.eagertarget))
+                else:
+                    aliasizer = sql_util.ClauseAdapter(self.eagertarget).\
+                        chain(sql_util.ClauseAdapter(self.eagersecondary))
                 self.eagersecondaryjoin = eagerloader.polymorphic_secondaryjoin.copy_container()
-                self.aliasizer.traverse(self.eagersecondaryjoin)
+                aliasizer.traverse(self.eagersecondaryjoin)
                 self.eagerprimary = eagerloader.polymorphic_primaryjoin.copy_container()
-                self.aliasizer.traverse(self.eagerprimary)
+                aliasizer.traverse(self.eagerprimary)
             else:
                 self.eagerprimary = eagerloader.polymorphic_primaryjoin.copy_container()
-                self.aliasizer = sql_util.Aliasizer(self.target, aliases={self.target:self.eagertarget})
-                self.aliasizer.traverse(self.eagerprimary)
-
-            if parentclauses is not None:
-                parentclauses.aliasizer.traverse(self.eagerprimary)
+                if parentclauses is not None: 
+                    aliasizer = sql_util.ClauseAdapter(self.eagertarget)
+                    aliasizer.chain(sql_util.ClauseAdapter(parentclauses.eagertarget, exclude=eagerloader.parent_property.remote_side))
+                else:
+                    aliasizer = sql_util.ClauseAdapter(self.eagertarget)
+                aliasizer.traverse(self.eagerprimary)
 
             if eagerloader.order_by:
-                self.eager_order_by = self._aliasize_orderby(eagerloader.order_by)
+                self.eager_order_by = sql_util.ClauseAdapter(self.eagertarget).copy_and_process(util.to_list(eagerloader.order_by))
             else:
                 self.eager_order_by = None
 
@@ -413,14 +417,6 @@ class EagerLoader(AbstractRelationLoader):
             # use the first 4 digits of an MD5 hash
             return "anon_" + util.hash(self.id + extra)[0:4]
             
-        def _aliasize_orderby(self, orderby, copy=True):
-            if copy:
-                return self.aliasizer.copy_and_process(util.to_list(orderby))
-            else:
-                orderby = util.to_list(orderby)
-                self.aliasizer.process_list(orderby)
-                return orderby
-
         def _create_decorator_row(self):
             class EagerRowAdapter(object):
                 def __init__(self, row):
diff --git a/lib/sqlalchemy/sql.py b/lib/sqlalchemy/sql.py
index ab64d65287..fe987cc11e 100644
--- a/lib/sqlalchemy/sql.py
+++ b/lib/sqlalchemy/sql.py
@@ -828,7 +828,21 @@ class ClauseVisitor(object):
     def traverse(self, obj):
         for n in obj.get_children(**self.__traverse_options__):
             self.traverse(n)
-        obj.accept_visitor(self)
+        v = self
+        while v is not None:
+            obj.accept_visitor(v)
+            v = getattr(v, '_next', None)
+        
+    def chain(self, visitor):
+        """'chain' an additional ClauseVisitor onto this ClauseVisitor.
+        
+        the chained visitor will receive all visit events after this one."""
+        tail = self
+        while getattr(tail, '_next', None) is not None:
+            tail = tail._next
+        tail._next = visitor
+        return self
+        
     def visit_column(self, column):
         pass
     def visit_table(self, table):
diff --git a/lib/sqlalchemy/sql_util.py b/lib/sqlalchemy/sql_util.py
index 1d185bbc5f..dcd19f8915 100644
--- a/lib/sqlalchemy/sql_util.py
+++ b/lib/sqlalchemy/sql_util.py
@@ -151,31 +151,8 @@ class AbstractClauseProcessor(sql.NoColumnVisitor):
         if elem is not None:
             binary.right = elem
 
-class Aliasizer(AbstractClauseProcessor):
-    """Convert a table instance within an expression to be an alias of that table."""
-
-    def __init__(self, *tables, **kwargs):
-        self.tables = {}
-        self.aliases = kwargs.get('aliases', {})
-        for t in tables:
-            self.tables[t] = t
-            if not self.aliases.has_key(t):
-                self.aliases[t] = sql.alias(t)
-            if isinstance(t, sql.Join):
-                for t2 in t.columns:
-                    self.tables[t2.table] = t2
-                    self.aliases[t2.table] = self.aliases[t]
-        self.binary = None
-
-    def get_alias(self, table):
-        return self.aliases[table]
-
-    def convert_element(self, elem):
-        if isinstance(elem, sql.ColumnElement) and hasattr(elem, 'table') and self.tables.has_key(elem.table):
-            return self.get_alias(elem.table).corresponding_column(elem)
-        else:
-            return None
-
+    # TODO: visit_select().  
+    
 class ClauseAdapter(AbstractClauseProcessor):
     """Given a clause (like as in a WHERE criterion), locate columns
     which are embedded within a given selectable, and changes those