[SQLObject] Patch for setdefault & replace constructors

[Carlos R. <car...@gm...>]

Hi all,

Here follows a simple-minded patch for the setdefault & replace
methods. It's pretty simple, and it helped to make my own code read a
little less cluttered :-)

 'setdefault' is useful to initialize a database with default objects.
It ensures that the object exists, but allow customizations to be
preserved. 'replace' writes the new values over the existing record,
and thus preserves the same original id. It can be used to reset
values to the default ones. Usage is as follows:

    # user contains the system users table. here we create the admin
    # account if it doesn't exist yet. It's just a sample, mind you...
    User.setdefault(testKey=3D'name', name=3D'admin', password=3D'admin')

    # this is similar to the test above, but the user account is overwriten
    # with the new definition
    User.replace(testKey=3D'name', name=3D'admin', password=3D'admin')

I was in doubt whether to include the 'testKey' argument or not. Both
methods could scan the table columns looking for some alternate key &
the corresponding  kw declaration. However, I thought that 'explicit
is better than implicit' and put it as an additional argument, which
helps to document the difference between these constructors and the
standard one.

p.s. There's no unit test, but I tested it inside my own system code
and it worked.

=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=
=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D
--- sqlobject/main.py   (revis=C3=A3o 619)
+++ sqlobject/main.py   (c=C3=B3pia de trabalho)
@@ -1029,6 +1029,33 @@

         self._create(id, **kw)

+    def setdefault(cls, testKey, **kw):
+        # If the object exists, return it; if it doesn't exist, create
+        # a new one and return. testKey is the name of the alternateKey
+        # to used for testing. Its value should be provided as a keyword
+        # argument.
+        dbTestKey =3D cls._SO_columnDict[testKey].dbName
+        try:
+            obj =3D cls._SO_fetchAlternateID(dbTestKey, kw[testKey],
connection=3DNone)
+        except SQLObjectNotFound:
+            obj =3D cls(**kw)
+        return obj
+
+    setdefault =3D classmethod(setdefault)
+
+    def replace(cls, testKey, **kw):
+        # Overwrites an existing object with the values provided. If
+        # the object does not exist, create it.
+        dbTestKey =3D cls._SO_columnDict[testKey].dbName
+        try:
+            obj =3D cls._SO_fetchAlternateID(dbTestKey, kw[testKey],
connection=3DNone)
+            obj.set(**kw)
+        except SQLObjectNotFound:
+            obj =3D cls(**kw)
+        return obj
+
+    replace =3D classmethod(replace)
+
     def _create(self, id, **kw):

         self._SO_creating =3D True


--=20
Carlos Ribeiro
Consultoria em Projetos
blog: http://rascunhosrotos.blogspot.com
blog: http://pythonnotes.blogspot.com
mail: car...@gm...
mail: car...@ya...