Readme.rst

@@ -11,7 +11,7 @@ Usage
 
   import libkosokoso as kk
   import sqlalchemy as sa
-  base = sa.orm.declarative_base()
+  base = sa.ext.declarative.declarative_base()
 
   kk.__dict__.update(kk.init_base(base))
 

kosokoso.py

@@ -1,7 +1,7 @@
 import sqlalchemy as sa
 from sqlalchemy.orm import declared_attr
 from sqlalchemy.ext.associationproxy import association_proxy
-# from sqlalchemy import text
+from sqlalchemy import text
 
 import itertools
 import logging
@@ -14,26 +14,9 @@ Base = None
 
 class TagBase(object):
 
-    def __init__(self, tag_text=None):
-        super(Tag, self).__init__()
-        self.text = tag_text
-    
-    def __repr__(self):
-        return "kk_tag %s: %s" % (self.db_id, self.text)
-
     def __eq__(self, other):
         return self.text == other.text
 
-    db_id = sa.Column(sa.Integer, primary_key=True)
-    text = sa.Column(sa.Unicode(255), unique=True)
-    __tablename__ = "kk_tags"
-    # we disable batch to ensure that parents are inserted before
-    # children.
-    __mapper_args__ = {
-            # "primary_key": [db_id],
-            "batch": False
-    }
-
     class TaggedObjectCollection(object):
         __emulates__ = list
 
@@ -46,15 +29,12 @@ class TagBase(object):
             that sqlalchemy only notices the add when a TagAssociation
             is used.  If a class is added directly, we generate a
             TagAssociation and re-call this method with the
-            association, which then triggers the append event.
-
-            hang on, shouldn't this all be handled by the
-            associationproxy?"""
+            association, which then triggers the append event."""
 
             if isinstance(item, TagAssociation):
                 try:
-                    # logging.debug("adding assoc %s w/ %s" % (item,
-                    #     _sa_initiator))
+                    logging.debug("adding assoc %s w/ %s" % (item,
+                        _sa_initiator))
                     # this has to be done first.
                     adapter = sa.orm.collections.collection_adapter(self)
                     item = adapter.fire_append_event(item, _sa_initiator)
@@ -79,47 +59,13 @@ class TagBase(object):
 
         def remove(self, item):
             pass
-
-        # 'extend' is apparently taken?
-        def merge(self, iterable):
-            logging.debug('merge called')
-            for i in iterable:
-                for j in self.data:
-                    if (i.target_table == j.target_table and
-                            i.target_id == j.target_id):
-                        logging.info(f'item {i} already in collection')
-                        break
-                else:
-                    logging.info(f'adding {i}')
-                    self.append(i)
-                    continue
-
+        def extend(self, item):
+            pass
         def __iter__(self):
             return iter(self.data)
         def __len__(self):
             return len(self.data)
 
-        def __eq__(self, other):
-            pass
-            # if not isinstance(other, TaggedObjectCollection):
-            #     return False
-            # if len(self.data) ne len(other.data):
-                # return False
-
-            # s1 = sorted(self.data)
-            # s2 = sorted(other.data)
-            # for i in range(0, len(s1)):
-            #     if s1[i] ne s2[i]:
-            #         return False
-            # return True
-
-        def __repr__(self):
-            out = 'TaggedObjectCollection: ['
-            for i in self.data:
-                out += str(i) + '\n'
-            out += ']'
-            return out
-
         def _get_class_by_tablename(self, tablename):
             """Return class reference mapped to table.
 
@@ -134,12 +80,34 @@ class TagBase(object):
             #             and c.__tablename__ == tablename):
             #         return c
 
+
+    db_id = sa.Column(sa.Integer, primary_key=True)
+    # text = sa.Column(sa.Unicode(255, convert_unicode=False),
+    #         unique=True)
+    text = sa.Column(sa.Unicode(255), unique=True)
     collection = sa.orm.relationship("TagAssociation",
             collection_class=TaggedObjectCollection,
             enable_typechecks=True,
-            primaryjoin="TagAssociation.tag_id==Tag.db_id",
-            back_populates="tag_obj"
+            primaryjoin="TagAssociation.tag_id==Tag.db_id"
             )
+    __tablename__ = "kk_tags"
+    # we disable batch to ensure that parents are inserted before
+    # children.
+    __mapper_args__ = {
+            # "primary_key": [db_id],
+            "batch": False
+    }
+
+    def __init__(self, tag_text=None):
+        super(Tag, self).__init__()
+        self.text = tag_text
+    
+    def __repr__(self):
+        return "kk_tag %s: %s" % (self.db_id, self.text)
+
+    # i'm not sure this is really what we want.
+    def __eq__(self, other):
+        return self.text == other.text
 
 
 class TagAssociationBase(object):
@@ -153,10 +121,8 @@ class TagAssociationBase(object):
             "polymorphic_on": "target_table"
     }
 
-    # at import time, Tag doesn't exist, so we use declared_attr to
-    # defer.
     @declared_attr
-    def tag_obj(cls):
+    def tag_obj(self):
         return sa.orm.relationship(Tag)
 
     tag = association_proxy("tag_obj", "text")
@@ -168,19 +134,12 @@ class TagAssociationBase(object):
             return False
         return self.db_id == other.db_id
 
-    def __lt__(self, other):
-        if not isinstance(other, TagAssociation):
-            return False
-        k1 = str(self.tag_obj.text) + self.target_table + str(self.target_id)
-        k2 = str(other.tag_obj.text) + other.target_table + str(other.target_id)
-        return k1 < k2
-
-    # @property
-    # def parent(self):
-    #     return getattr(self, "%s_parent" % self.target_table)
+    @property
+    def parent(self):
+        return getattr(self, "%s_parent" % self.target_table)
 
     def __repr__(self):
-        return "tag assoc %s: [%s] %s:%s" % (self.db_id, self.tag_obj.text, 
+        return "tag assoc %s: %s:%s" % (self.db_id, 
                 self.target_table, self.target_id)
 
 
@@ -194,7 +153,7 @@ class TaggableBase(object):
 
         def cls_init(self, tag=None):
             # traceback.print_stack()
-            # logging.debug("cls_init called, type %s".format(table))
+            logging.debug("cls_init called, type %s".format(table))
             super(TagAssociation, self).__init__()
             self.target_table = table
             # is this necessary?  how does this get called?
@@ -202,12 +161,12 @@ class TaggableBase(object):
                 if isinstance(tag, Tag):
                     self.tag_obj = tag
                 else:
-                    # logging.debug("cls init called with text %s" % tag)
+                    logging.debug("cls init called with text %s" % tag)
                     self.tag_obj = Tag(tag)
 
 
         assoc_cls = type(
-                f"{name}TagAssociation",
+                "%sTagAssociation" % name,
                 (TagAssociation, ),
                 dict(
                     __mapper_args__ = {
@@ -219,6 +178,7 @@ class TaggableBase(object):
         )
         cls.tags = association_proxy("kk_tag_associations", "tag")
 
+
         return sa.orm.relationship(
                 assoc_cls,
                 primaryjoin=(
@@ -228,7 +188,6 @@ class TaggableBase(object):
                 )
 
 
-
 def init_base(new_base):
     """Set up classes based on new_base."""
     # based on https://stackoverflow.com/a/41927212
@@ -246,97 +205,33 @@ def init_base(new_base):
 
     globals()['Base'] = new_base
 
+    # these are here because "Tag" needs to exist before adding the
+    # listener.
+    sa.event.listen(Tag, 'before_insert', delete_before_insert)
+    sa.event.listen(sa.orm.session.Session, 'before_flush',
+            enforce_unique_text)
+
+    # need to return new types so that the caller can incorporate them
+    # into its view of the module.
     return ret
 
 
-@sa.event.listens_for(sa.orm.Session, 'before_flush')
-def merge_text_tags(session, ctx, instances):
-    texts = {}
-    for i in session.new:
-        if isinstance(i, Tag):
-            t = session.query(Tag).filter_by(text=i.text).first()
-            if t:
-                logging.info(f'got t, merging')
-                i.db_id = t.db_id
-                t.collection.merge(i.collection)
-
-                # t = session.merge(i)
-                session.expunge(i)
-            elif i.text in texts:
-                logging.info('have text, not sure how to proceed.')
-                session.expunge(i)
-            else:
-                texts[i.text] = i
-
-# @sa.event.listens_for(sa.orm.Session, "before_attach")
-# def intercept(session, instance):
-#     if not isinstance(instance, Tag):
-#         logging.info(f'got non-tag {instance}')
-#         return
-# 
-#     # i guess this only returns stuff that's persistent?
-#     logging.info(f'have tag {instance}')
-#     t = session.query(Tag).filter_by(text=instance.text).first()
-#     if t:
-#         logging.info(f'have tag {instance}')
-#         instance.db_id = t.db_id
-#         session.merge(instance)
-#     return
-
+def delete_before_insert(mapper, conn, target):
+    # TODO figure out where exactly transactions happen.
+    # TODO can we just upsert?  Or, for that matter, skip the insert?
+    r = conn.execute(text("SELECT db_id FROM kk_tags WHERE text='%s'" %
+            target.text))
+    if r:
+        conn.execute(text("DELETE FROM kk_tags WHERE text='%s'" %
+                          target.text))
 
 # i'm not sure if this is necessary -- its purpose is to set the id on
 # our new instance to ensure it matches the old instance.  if this
 # isn't done, it seems like the id might change, breaking old links.
-# @sa.event.listens_for(sa.orm.Session, "before_flush")
-# def enforce_unique_text(session, flush_context, instances):
-#     texts = []
-#     for i in session.new:
-#         if isinstance(i, Tag):
-#             t = session.query(Tag).filter_by(text=i.text).first()
-#             if t:
-#                 logging.info(f'got t, merging')
-#                 i.db_id = t.db_id
-#                 session.merge(t)
-#             elif i.text in texts:
-#                 logging.info('have text, not sure how to proceed.')
-#             else:
-#                 texts.append(i.text)
-
-
-# FIXME we could probably do this more effectively if we listen for
-# the object event, not session.
-# @sa.event.listens_for(sa.orm.Session, "before_flush")
-# def delete_before_insert(session, context, instances):
-#     tags = []
-#     logging.info('calling delete_before_insert')
-#     for instance in session.dirty:
-#         if isinstance(instance, Tag):
-#             logging.info('have dirty tag')
-#             tags.append(instance.text)
-#     for instance in session.new:
-#         if not isinstance(instance, Tag):
-#             logging.info('got non-tag')
-#             continue
-#         # if not session.is_modified(instance):
-#         #     continue
-# 
-#         logging.info(f'have tag {instance}')
-#         t = session.query(Tag).filter_by(text=instance.text).first()
-#         # conn = session.connection()
-#         # r = conn.execute(text("SELECT db_id FROM kk_tags WHERE text='%s'" %
-#         #         instance.text))
-#         # apparently this is -1 if the query matches no rows
-#         # if r.rowcount > 0:
-#         if t:
-#             session.expunge(instance)
-#         else:
-#             logging.info('no row')
-# 
-#         # handle the case where we have multiples of the same tag in
-#         # new
-#         logging.info(f'{tags}')
-#         if instance.text in tags:
-#             session.expunge(instance)
-#         else:
-#             tags.append(instance.text)
+def enforce_unique_text(session, flush_context, instances):
+    for i in session.new:
+        if isinstance(i, Tag):
+            t = session.query(Tag).filter_by(text=i.text).first()
+            if t:
+                i.db_id = t.db_id
 

tests/test_basic.py

@@ -13,18 +13,14 @@ import unittest
 
 from sqlalchemy import text
 
+# from . import kosokoso as kk
 import libkosokoso as kk
 
-class DummyBase(sa.orm.DeclarativeBase):
-    pass
-# This is because presumably you have a declarative_base that you're
-# already using, and obviously sqalchemy only allows relationships
-# between objects with the same base.  Hence, init_base dynamically
-# generates classes derived from the base.
+# DummyBase = sa.orm.declarative_base()
+DummyBase = orm.declarative_base()
 kk.__dict__.update(kk.init_base(DummyBase))
 
 # TODO make it so DummyBase doesn't have to come after the mixin.
-# Actually, is DummyBase needed at all?
 class Foo(kk.Taggable, DummyBase):
     __tablename__ = 'foos'
     db_id = sa.Column(sa.Integer, primary_key=True)
@@ -92,9 +88,9 @@ class ks_basic(unittest.TestCase):
 
         self.session.add(t1)
         self.session.add(t2)
-        self.session.commit()
+        # self.session.commit()
 
-        del t1, t2
+        # del t1, t2
         ts = self.session.query(kk.Tag).all()
         self.assertEqual(1, len(ts))
 
@@ -196,32 +192,6 @@ class ks_basic(unittest.TestCase):
         self.assertEqual(l[0], f1)
         self.assertTrue(isinstance(l[2], Bar))
 
-    # @unittest.skip
-    def test_merge_collection(self):
-        f1 = Foo()
-        f2 = Foo()
-        t1 = kk.Tag('tag1')
-        t2 = kk.Tag('tag2')
-        # all this stuff has to be in the database to get an id.
-        # FIXME make tagging in general work with transient objects.
-        self.session.add(f1)
-        self.session.add(f2)
-        self.session.add(t1)
-        self.session.add(t2)
-        self.session.commit()
-
-        t1.collection.append(f1)
-        t1.collection.append(f2)
-        t2.collection.append(f2)
-        t2.collection.merge(t1.collection)
-        c1 = sorted(t1.collection)
-        c2 = sorted(t2.collection)
-
-        self.assertEqual(len(t1.collection), len(t2.collection))
-        # FIXME doesn't work because collection equality includes
-        # equality of tag names, which of course doesn't exist.
-        # self.assertEqual(t1.collection, t2.collection)
-
     def test_association(self):
         a = Foo()
         b = Foo()
@@ -359,25 +329,21 @@ class ks_basic(unittest.TestCase):
         actual = '\n'.join(actual)
         self.assertEqual(expected, '\n%s' % actual)
 
-    # @unittest.skip
     def test_addstring_repeated(self):
         a1 = Foo()
         a2 = Foo()
 
         a1.tags.append("tag1")
         a2.tags.append("tag1")
-        # implicitly adds tags.
         self.session.add(a1)
         # self.session.commit()
-        # this does an autoflush.
         t = self.session.query(kk.Tag).filter_by(text="tag1").first()
         self.assertEqual(t.text, "tag1")
         self.assertEqual(t.db_id, 1)
         self.session.add(a2)
-        # FIXME committing here causes the test to fail.
         # self.session.commit()
-        # self.assertEqual(a2.tags, ['tag1'])
-        # print(pd.read_sql_query(text("SELECT * FROM kk_tags"),
+        self.assertEqual(a2.tags, ['tag1'])
+        # print(pd.read_sql_query("SELECT * FROM kk_tags",
         #     self.engine))
 
         del a1, a2, t