diff options
Diffstat (limited to 'lib/sqlalchemy/mapper.py')
| -rw-r--r-- | lib/sqlalchemy/mapper.py | 57 |
1 files changed, 41 insertions, 16 deletions
diff --git a/lib/sqlalchemy/mapper.py b/lib/sqlalchemy/mapper.py index 855c7e289..ae8f70859 100644 --- a/lib/sqlalchemy/mapper.py +++ b/lib/sqlalchemy/mapper.py @@ -22,7 +22,7 @@ import sqlalchemy.util as util import sqlalchemy.objectstore as objectstore import random, copy, types -__ALL__ = ['eagermapper', 'eagerloader', 'lazymapper', 'lazyloader', 'eagerload', 'lazyload', 'assignmapper', 'mapper', 'lazyloader', 'lazymapper', 'clear_mappers', 'objectstore', 'sql'] +__ALL__ = ['eagermapper', 'eagerloader', 'lazymapper', 'lazyloader', 'eagerload', 'lazyload', 'assignmapper', 'mapper', 'lazyloader', 'lazymapper', 'clear_mappers', 'objectstore', 'sql', 'MapperExtension'] def relation(*args, **params): if isinstance(args[0], type) and len(args) == 1: @@ -32,14 +32,16 @@ def relation(*args, **params): else: return relation_mapper(*args, **params) -def relation_loader(mapper, secondary = None, primaryjoin = None, secondaryjoin = None, lazy = True, **options): +def relation_loader(mapper, secondary = None, primaryjoin = None, secondaryjoin = None, lazy = True, **kwargs): if lazy: - return LazyLoader(mapper, secondary, primaryjoin, secondaryjoin, **options) + return LazyLoader(mapper, secondary, primaryjoin, secondaryjoin, **kwargs) + elif lazy is None: + return PropertyLoader(mapper, secondary, primaryjoin, secondaryjoin, **kwargs) else: - return EagerLoader(mapper, secondary, primaryjoin, secondaryjoin, **options) + return EagerLoader(mapper, secondary, primaryjoin, secondaryjoin, **kwargs) -def relation_mapper(class_, table = None, secondary = None, primaryjoin = None, secondaryjoin = None, primarytable = None, properties = None, lazy = True, foreignkey = None, primary_keys = None, thiscol = None, **options): - return relation_loader(mapper(class_, table, primarytable=primarytable, properties=properties, primary_keys=primary_keys, **options), secondary, primaryjoin, secondaryjoin, lazy = lazy, foreignkey = foreignkey, thiscol = thiscol, **options) +def relation_mapper(class_, table=None, secondary=None, primaryjoin=None, secondaryjoin=None, **kwargs): + return relation_loader(mapper(class_, table, **kwargs), secondary, primaryjoin, secondaryjoin, **kwargs) class assignmapper(object): def __init__(self, table, **kwargs): @@ -110,8 +112,13 @@ class Mapper(object): is_primary = False, inherits = None, inherit_condition = None, + extension = None, **kwargs): - + + if extension is None: + self.extension = MapperExtension() + else: + self.extension = extension self.hashkey = hashkey self.class_ = class_ self.scope = scope @@ -174,6 +181,7 @@ class Mapper(object): if properties is not None: for key, prop in properties.iteritems(): if isinstance(prop, schema.Column): + self.columns[key] = prop prop = ColumnProperty(prop) self.props[key] = prop if isinstance(prop, ColumnProperty): @@ -264,8 +272,11 @@ class Mapper(object): except IndexError: return None - def identity_key(self, instance): - return objectstore.get_id_key(tuple([self._getattrbycolumn(instance, column) for column in self.primary_keys[self.table]]), self.class_, self.primarytable) + def identity_key(self, *primary_keys): + return objectstore.get_id_key(tuple(primary_keys), self.class_, self.primarytable) + + def instance_key(self, instance): + return self.identity_key(**[self._getattrbycolumn(instance, column) for column in self.primary_keys[self.table]]) def compile(self, whereclause = None, **options): """works like select, except returns the SQL statement object without @@ -418,8 +429,6 @@ class Mapper(object): identitykey = self._identity_key(row) if objectstore.uow().has_key(identitykey): instance = objectstore.uow()._get(identitykey) - if result is not None: - result.append_nohistory(instance) if populate_existing: isnew = not imap.has_key(identitykey) @@ -428,6 +437,10 @@ class Mapper(object): for prop in self.props.values(): prop.execute(instance, row, identitykey, imap, isnew) + if self.extension.append_result(self, row, imap, result, instance, populate_existing=populate_existing): + if result is not None: + result.append_nohistory(instance) + return instance # look in result-local identitymap for it. @@ -439,7 +452,8 @@ class Mapper(object): if row[col.label] is None: return None # plugin point - instance = self.class_() + if self.extension.create_instance(self, row, imap, self.class_) is None: + instance = self.class_() instance._mapper = self.hashkey instance._instance_key = identitykey @@ -449,8 +463,6 @@ class Mapper(object): instance = imap[identitykey] isnew = False - if result is not None: - result.append_nohistory(instance) # plugin point @@ -458,6 +470,10 @@ class Mapper(object): # instances from the row and possibly populate this item. for prop in self.props.values(): prop.execute(instance, row, identitykey, imap, isnew) + + if self.extension.append_result(self, row, imap, result, instance, populate_existing=populate_existing): + if result is not None: + result.append_nohistory(instance) return instance @@ -533,7 +549,7 @@ class PropertyLoader(MapperProperty): """describes an object property that holds a single item or list of items that correspond to a related database table.""" - def __init__(self, argument, secondary, primaryjoin, secondaryjoin, foreignkey = None, uselist = None, private = False, thiscol = None): + def __init__(self, argument, secondary, primaryjoin, secondaryjoin, foreignkey = None, uselist = None, private = False, thiscol = None, **kwargs): self.uselist = uselist self.argument = argument self.secondary = secondary @@ -806,7 +822,10 @@ class PropertyLoader(MapperProperty): associationrow[colmap[self.secondary].key] = self.parent._getattrbycolumn(obj, colmap[self.parent.primarytable]) elif colmap.has_key(self.target) and colmap.has_key(self.secondary): associationrow[colmap[self.secondary].key] = self.mapper._getattrbycolumn(child, colmap[self.target]) - + + def execute(self, instance, row, identitykey, imap, isnew): + pass + class LazyLoader(PropertyLoader): def execute(self, instance, row, identitykey, imap, isnew): if isnew: @@ -962,6 +981,12 @@ class BinaryVisitor(sql.ClauseVisitor): def visit_binary(self, binary): self.func(binary) + +class MapperExtension(object): + def create_instance(self, mapper, row, imap, class_): + return None + def append_result(self, mapper, row, imap, result, instance, populate_existing=False): + return True def hash_key(obj): if obj is None: |