Encapsulate your business logic in command classes.
Project description
Mutations
Compose your business logic into commands that sanitize and validate input.
Install
$ pip install mutations
How it Works:
- Subclass
mutations.Mutation
- Define your inputs.
- Define an
execute
method in your command. - Run it, like this:
SimpleMutation.run(foo='bar')
To learn more, see this blog post.
Example
import mutations
class UserSignup(mutations.Mutation):
"""Define the inputs to your mutation here. """
email = mutations.fields.CharField(required=True)
full_name = mutations.fields.CharField(required=True)
send_welcome_email = mutations.fields.Boolean(required=False, default=True)
def validate_email_address(self):
"""Custom validation for a field.
If you encounter any validation errors and want to raise, you should
raise mutation.ValidationError or some sublcass thereof. Otherwise, it
assumes there were no problems.
Any function beginning with `validate_` is assumed to be a validator
function and will be run before the mutation can execute.
"""
if not self.email.is_valid():
raise mutations.ValidationError("email_not_valid", "Email is not valid.")
def execute(self):
"""Executes the mutation.
This method does the heavy lifting. You can call it by calling .run() on
your mutation class.
"""
user = User.objects.create(email=self.email, name=self.full_name)
if self.send_welcome_email:
EmailServer.deliver(recipient = self.email)
return user
Calling Commands
>>> result = UserSignup.run(email=email, full_name="Bob Boblob")
>>> result.success
True
>>> result.return_value
<User id=...>
>>> result.errors
result = ...
>>> result = UserSignup.run(email=None)
>>> result.success
False
>>> result.errors
mutations.ErrorDict({
'email': ['email_not_valid']
})
>>> result.value
None
Only Run Validations
>>> result = UserSignup.validate(email=email, full_name="Bob Boblob")
>>> result.is_valid
True
Testing
$ make tests
When you're ready to do a release, please make sure tests pass across both 2.7 and 3.6 by running tox:
$ tox
Versioning
This project uses Semantic Versioning.
Thanks
Thanks to Cypriss for the excellent Ruby Mutations Gem. I created this library because I was looking for something similar for Python.
Project details
Download files
Download the file for your platform. If you're not sure which to choose, learn more about installing packages.
Source Distribution
mutations-0.4.0.tar.gz
(5.5 kB
view hashes)