Active Record like validation on SQLAlchemy declarative model objects
Project description
Introduction
SAValidation facilitates Active Record like validation on SQLAlchemy declarative model objects.
You can install the in-development version of savalidation with easy_install savalidation==dev.
The home page is currently the GitHub repository.
Usage Example
The following is a snippet from the examples.py file:
from datetime import datetime
import formencode
import sqlalchemy as sa
import sqlalchemy.ext.declarative as sadec
import sqlalchemy.sql as sasql
import sqlalchemy.orm as saorm
from savalidation import ValidationMixin, watch_session
import savalidation.validators as val
engine = sa.create_engine('sqlite://')
#engine.echo = True
meta = sa.MetaData()
Base = sadec.declarative_base(metadata=meta)
Session = saorm.scoped_session(
saorm.sessionmaker(
bind=engine,
autoflush=False
)
)
sess = Session
class Family(Base, ValidationMixin):
__tablename__ = 'families'
# SA COLUMNS
id = sa.Column(sa.Integer, primary_key=True)
createdts = sa.Column(sa.DateTime, nullable=False, default=datetime.now, server_default=sasql.text('CURRENT_TIMESTAMP'))
updatedts = sa.Column(sa.DateTime, onupdate=datetime.now)
name = sa.Column(sa.Unicode(75), nullable=False, unique=True)
reg_num = sa.Column(sa.Integer, nullable=False, unique=True)
status = sa.Column(sa.Unicode(15), nullable=False, default=u'active', server_default=u'active')
# VALIDATION
STATUS_CHOICES = (
('active', 'Active'),
('inactive', 'Inactive'),
('moved', 'Moved'),
)
# will validate nullability and string types
val.validates_constraints()
val.validates_one_of('status', [k for k, v in STATUS_CHOICES])
#OTHER
def __str__(self):
return '<Family id=%s, name=%s>' % (self.id, self.name)
class Person(Base, ValidationMixin):
__tablename__ = 'people'
id = sa.Column(sa.Integer, primary_key=True)
createdts = sa.Column(sa.DateTime, nullable=False, server_default=sasql.text('CURRENT_TIMESTAMP'))
updatedts = sa.Column(sa.DateTime, onupdate=datetime.now)
name_first = sa.Column(sa.Unicode(75), nullable=False)
name_last = sa.Column(sa.Unicode(75), nullable=False)
family_role = sa.Column(sa.Unicode(20), nullable=False)
nullable_but_required = sa.Column(sa.Unicode(5))
ROLE_CHOICES = (
('father', 'Father'),
('mother', 'Mother'),
('child', 'Child'),
)
val.validates_constraints(exclude='createdts')
val.validates_presence_of('nullable_but_required')
val.validates_choices('family_role', ROLE_CHOICES)
class ReverseConverter(formencode.api.FancyValidator):
def _to_python(self, value, state):
if not isinstance(value, basestring):
raise formencode.Invalid('Must be a string type', value, state)
# this reverse a string or list...yah, I know, it looks funny
return value[::-1]
validates_reverse = val.formencode_factory(ReverseConverter)
converts_reverse = val.formencode_factory(ReverseConverter, sv_convert=True)
class ConversionTester(Base, ValidationMixin):
__tablename__ = 'conversion_testers'
id = sa.Column(sa.Integer, primary_key=True)
val1 = sa.Column(sa.String(25))
val2 = sa.Column(sa.String(25))
val3 = sa.Column(sa.String(25))
val4 = sa.Column(sa.String(25))
validates_reverse('val1')
validates_reverse('val2', sv_convert=True)
converts_reverse('val3')
converts_reverse('val4', sv_convert=False)
See more examples in the tests directory of the distribution.
Installing & Testing Source
(this is one way, there are others)
# create a virtualenv
# activate the virtualenv
$ pip install -e git+git://github.com/blazelibs/sqlalchemy-validation.git@master#egg=savalidation
$ pip install nose
$ cd src/savalidation/savalidation
$ nosetests
Questions & Comments
Please visit: http://groups.google.com/group/blazelibs
Known Issues
Final values that get set on an ORM mapped object attributes through relationships, the default or onupdate column parameters, and possibly others are not availble at the time validation is done.
In some cases, this can be caught after the flush (before commit) when those values become available on the ORM object.
Unfortunately, that is of limited value in the case where the the value that slipped through violates a DB constraint. In that case, a true DB exception will be raised.
Dependencies
SQLAlchemy > 0.7.6
FormEncode
python-dateutil (for date/time converters)
Nose (if you want to run the tests)
Credits
This project borrows code and ideas from:
Current Status
The code itself seems stable, but the API may change in the future.
Change Log
0.4.1 released 2016-11-23
fixed Python versions listed for package
fixed a broken link in the readme to the Elixir project
updated CircleCI setup and added AppVeyor
0.4.0 released 2016-06-10
added support for Python 3.4+ (thanks to Jiří Bireš)
set up continuous integration on Circle CI
coverage reports through CodeCov
0.3.2 released 2016-04-20
validate precision and scale of numeric column values
0.3.1 released 2016-02-23
fix formencode compatibility, supports formencode 1.2 and 1.3
0.3.0 released 2014-09-30
fix bug with .validates_constraints() and Text column types
watch_session() is no longer needed, SQLAlchemy >= 0.7.6 required
now beta quality: been used in production a long time, but not used widely
0.2.1 released 2013-05-15
fixed issue #6 - adjustment to the version of python-dateutil required.
0.2.0 released 2012-10-24
This release contains some BC BREAKS.
internal API cleaned up
refactored to use SQLAlchemy (SA) events, we are now compatable with & require SA >= 0.7
CHANGE: if using SA < 0.7.6, savalidation.watch_session() must be called with each instance of your session IF the savalidation module is being instantiated before your session is created.
CHANGE: the validator API has changed. If you have created custom validators you will need to look at the changes in validators.py.
the Formencode state object sent to a validator’s method has changed the “instance” attribute to be “entity.”
add before_flush() helper to decorate entity instance methods
- got rid of after_flush validation. Instead, before_insert/before_update events
can now be used to validate non-nullable foreign keys.
- got rid of validation support for a column’s default and server_default
values (b/c it required after_flush validation)
- formencode schemas are now only created once per class, not per instance,
boosting performance.
0.1.5 released 2011-06-11
fix 0.1.4 release which didn’t include version file
0.1.4 released 2011-06-11
change python-dateutil dependence to < 2.0, 2.x is for python 3
0.1.3 released 2011-05-19
change SQLAlchemy requirement so the latest package < 0.7 is installed
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