diff options
Diffstat (limited to 'lib/sqlalchemy/sql/visitors.py')
| -rw-r--r-- | lib/sqlalchemy/sql/visitors.py | 35 |
1 files changed, 35 insertions, 0 deletions
diff --git a/lib/sqlalchemy/sql/visitors.py b/lib/sqlalchemy/sql/visitors.py index 93ee8eb1c..c750c546a 100644 --- a/lib/sqlalchemy/sql/visitors.py +++ b/lib/sqlalchemy/sql/visitors.py @@ -24,6 +24,7 @@ http://techspot.zzzeek.org/2008/01/23/expression-transformations/ . """ from collections import deque +import itertools import operator from .. import exc @@ -119,6 +120,38 @@ class Traversible(util.with_metaclass(TraversibleType)): """ + @util.preload_module("sqlalchemy.sql.traversals") + def get_children(self, omit_attrs=(), **kw): + r"""Return immediate child :class:`.visitors.Traversible` + elements of this :class:`.visitors.Traversible`. + + This is used for visit traversal. + + \**kw may contain flags that change the collection that is + returned, for example to return a subset of items in order to + cut down on larger traversals, or to return child items from a + different context (such as schema-level collections instead of + clause-level). + + """ + + traversals = util.preloaded.sql_traversals + + try: + traverse_internals = self._traverse_internals + except AttributeError: + # user-defined classes may not have a _traverse_internals + return [] + + dispatch = traversals._get_children.run_generated_dispatch + return itertools.chain.from_iterable( + meth(obj, **kw) + for attrname, obj, meth in dispatch( + self, traverse_internals, "_generated_get_children_traversal" + ) + if attrname not in omit_attrs and obj is not None + ) + class _InternalTraversalType(type): def __init__(cls, clsname, bases, clsdict): @@ -393,6 +426,8 @@ class InternalTraversal(util.with_metaclass(_InternalTraversalType, object)): dp_setup_join_tuple = symbol("SJ") + dp_memoized_select_entities = symbol("ME") + dp_statement_hint_list = symbol("SH") """Visit the ``_statement_hints`` collection of a :class:`_expression.Select` |