Skip to main content

Encapsulate your business logic in command classes.

Project description

Mutations

pypi-version

Compose your business logic into commands that sanitize and validate input.

Install

$ pip install mutations

How it Works:

  1. Subclass mutations.Mutation
  2. Define your inputs.
  3. Define an execute method in your command.
  4. 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 details)

Uploaded Source

File details

Details for the file mutations-0.4.0.tar.gz.

File metadata

  • Download URL: mutations-0.4.0.tar.gz
  • Upload date:
  • Size: 5.5 kB
  • Tags: Source
  • Uploaded using Trusted Publishing? No
  • Uploaded via: twine/1.11.0 pkginfo/1.4.2 requests/2.18.4 setuptools/39.2.0 requests-toolbelt/0.8.0 tqdm/4.23.4 CPython/3.6.5

File hashes

Hashes for mutations-0.4.0.tar.gz
Algorithm Hash digest
SHA256 813d57b48adaeb643d0d8c66f4b0bb7f74a26452cdc4ceaca312daca92572a00
MD5 e05c3658f3c859d68824388152b06ba8
BLAKE2b-256 e92cdb7144437418ccd7137cb5075f808e10df9068773265bbf6544dfc93e66c

See more details on using hashes here.

Supported by

AWS AWS Cloud computing and Security Sponsor Datadog Datadog Monitoring Fastly Fastly CDN Google Google Download Analytics Microsoft Microsoft PSF Sponsor Pingdom Pingdom Monitoring Sentry Sentry Error logging StatusPage StatusPage Status page