pluserable 0.9.0

Generic user registration for the Pyramid web framework

pluserable provides generic user registration for the Pyramid web framework, if your web app uses SQLAlchemy.

It is a pluggable web application that provides user registration, login, logout and change password functionality. pluserable follows a policy of minimal interference, so your app can mostly keep its existing models.

It is being refactored to support other web frameworks.

The documentation is at http://docs.nando.audio/pluserable/latest/

Minimal integration

• Create a virtualenv and activate it. Install pyramid and create your Pyramid project.

• Ensure you have some SQLAlchemy declarative initialization. This is usually created by the Pyramid scaffold.

• Edit your setup.py to add “pluserable” to the dependencies in the install_requires list.

• Run python setup.py develop on your project to install all dependencies into your virtualenv.

• Create models inheriting from pluserable’ abstract models. Find an example in the file pluserable/tests/models.py.

• In your Pyramid configuration file, create a section called “kerno utilities” like this:

  [kerno utilities]
      # Let pluserable know which model classes to use:
      activation class = some.app.models:Activation
      group class = some.app.models:Group
      user class = some.app.models:User
  
      # Give pluserable a SQLAlchemy session factory:
      session factory = some.app.models:get_sqlalchemy_session

• Above you are also pointing to a session factory. Just write a function that returns a SQLAlchemy session instance, ready for use. Alternatively, it can be a scoped session.

• You may write a function that returns a configuration for Pyramid routes and views (which is something you probably want to manipulate in code because it won’t change between dev, staging and production environments), and then inform pluserable about it like this:

  registry.settings['pluserable_configurator'] = 'my.package:some_function'

• Your pluserable_configurator function would look more or less like this:

  from pluserable.settings import get_default_pluserable_settings
  
  def my_pluserable(config):
      """This function is called by pluserable during app startup."""
      adict = get_default_pluserable_settings()
      # Manipulate adict to customize pluserable for your application, then
      return adict

• Include pluserable into your Pyramid application, just after Pyramid’s Configurator is instantiated:

  config.include('pluserable')

This does almost nothing: it only makes a new config method available. You have to use it next:

config.setup_pluserable(  # Directive that starts pluserable up
    global_settings['__file__'],  # Path to your INI configuration file
)

The above causes pluserable to read certain sections of your INI file – especially the [Kerno utilities] section.

The backend for database access is in a separate class, this way you can substitute the implementation. This is called the “repository” pattern. It is recommended that you use the repository pattern in your app, too. The pluserable repository is instantiated once per request. It is available in the request.repo variable.

• Configure pluserable.login_redirect and pluserable.logout_redirect (in your .ini configuration file) to set the redirection routes.

• If you haven’t done so yet, configure an HTTP session factory according to the Sessions chapter of the Pyramid documentation.

• Create your database and tables. Maybe even an initial user.

• Be sure to pass an authentication_policy argument in the config = Configurator(...) call. Refer to Pyramid docs for details.

• By now the login form should appear at /login, but /register shouldn’t.

• Include the package pyramid_mailer for the validation e-mail and “forgot password” e-mail:

  config.include('pyramid_mailer')

• The /register form should appear, though ugly. Now you have a choice regarding user activation by email:

  • You may just disable user activation by setting, in your .ini file:

    [pluserable]
        # (other settings, then...)
        require_activation = False

  • Otherwise, configure pyramid_mailer according to its documentation and test the registration page.

• If you are using pyramid_tm or the ZopeTransactionManager, your minimal integration is done. (The pages are ugly, but working. Keep reading…)

Need to session.commit()?

pluserable does not require pyramid_tm or the ZopeTransactionManager with your session but if you do not use them you do have to take one extra step. We don’t commit transactions for you because that just wouldn’t be nice!

All you have to do is subscribe to the extension events and commit the session yourself. This also gives you the chance to do some extra processing:

from pluserable.events import (
    EventRegistration, EventActivation, EventLogin,
    EventPasswordReset, EventProfileUpdated,
)

def handle_event(event):
    request = event.request
    session = request.registry.getUtility(IDBSession)
    session.commit()

kerno.events.subscribe(handle_event, EventRegistration)
kerno.events.subscribe(handle_event, EventActivation)
kerno.events.subscribe(handle_event, EventLogin)
kerno.events.subscribe(handle_event, EventPasswordReset)
kerno.events.subscribe(handle_event, EventProfileUpdated)

The kerno variable comes from your initialization of the kerno library, which is useful to define the domain model of your application. (The kerno variable represents a global object for the domain model – it does not know anything about the web framework.) At runtime pluserable finds the kerno instance at request.kerno. In the future pluserable will be independent of the Pyramid web framework.

Whether or not to have a “username” field

It is important that you analyze the characteristics of your web application and decide whether you need a username field for users to log in with. pluserable provides 2 modes of operation:

• email + username: The user chooses a username when registering and later she can log in by providing either the username or the email address. Therefore, usernames may NOT contain the @ character. This mode is the default. It is expressed by the configuration setting pluserable.handle = usermail

• email only: There is no username field and users only provide their email address. You enable this mode by:

  • Making your User model subclass NoUsernameMixin instead of UsernameMixin;

  • Adding this configuration setting: pluserable.handle = email, which will make pluserable default to schemas that contain email fields instead of username fields.

If you make this change and want to keep your data you must deal with the existing (or missing) “username” column yourself.

Changing the forms

If you would like to modify any of the forms, you just need to register the new deform class to be used.

The interfaces you have available to override from pluserable.interfaces are:

• IPluserableLoginForm

• IPluserableRegisterForm

• IPluserableForgotPasswordForm

• IPluserableResetPasswordForm

• IPluserableProfileForm

This is how you would do it (MyForm being a custom deform Form class):

config.registry.registerUtility(MyForm, IPluserableLoginForm)

Changing the templates

If you would like to substitute the templates you can use pyramid’s override_asset:

config.override_asset(to_override='pluserable:templates/template.mako',
    override_with='your_package:templates/anothertemplate.mako')

The templates you have available to override are:

• login.mako

• register.mako

• forgot_password.mako

• reset_password.mako

• profile.mako

If you would like to override the templates with Jinja2, or any other templating language, just override the view configuration:

config.add_view('pluserable.views.AuthController', attr='login',
    route_name='login', renderer='yourapp:templates/login.jinja2')
config.add_view('pluserable.views.ForgotPasswordController',
    attr='forgot_password', route_name='forgot_password',
    renderer='yourapp:templates/forgot_password.jinja2')
config.add_view('pluserable.views.ForgotPasswordController',
    attr='reset_password', route_name='reset_password',
    renderer='yourapp:templates/reset_password.jinja2')
config.add_view('pluserable.views.RegisterController', attr='register',
    route_name='register', renderer='yourapp:templates/register.jinja2')
config.add_view('pluserable.views.ProfileController', attr='profile',
    route_name='profile', renderer='yourapp:templates/profile.jinja2')

Changing strings

Take a look at this class. This is where we store all the strings in pluserable. If you’d like to change one or two messages, simply create a subclass and configure it:

[kerno utilities]
    # (...bla bla bla...)

    # Determining the UI strings is as easy as pointing to a class:
    string class = pluserable.strings:UIStringsBase

Here is an example implementation of a strings class:

class AuthStrings(UIStringsBase):
    """Our alterations to the pluserable UI text."""

    login_done = None   # Do not flash a message after the user logs in
    logout_done = None  # Do not flash a message after the user logs out

Changing the email messages

pluserable includes functions that send very simple, plain text only, email messages using pyramid_mailer. Messages are sent synchronously.

You can replace those with your own functions in order to send emails asynchronously (e. g. using celery), or to determine the content of the email messages. Plug your function in through kerno utilities – for example in configuration:

[kerno utilities]
pluserable.send_activation_email = myapp.actions:send_activation_email
pluserable.send_reset_password_email = myapp.actions:send_reset_password_email

…or imperatively in startup code:

eko.utilities.register(
    "pluserable.send_activation_email",
    "myapp.actions:send_activation_email"
)
eko.utilities.register(
    "pluserable.send_reset_password_email",
    "myapp.actions:send_reset_password_email"
)

Changing the primary key column name

If you wish to override the primary key attribute name, you can do so by creating a new mixin class:

class NullPkMixin(Base):
    abstract = True
    _idAttribute = 'pk'

    @declared_attr
    def pk(self):
        return Base.pk

    @declared_attr
    def id(self):
        return None

class User(NullPkMixin, UserMixin):
    pass

Developing your application

Every request object will have a “user” variable containing the User instance of the person who logged in. This is reified – meaning the query to retrieve the user data only happens once per request.

So do use request.user in your code.

pluserable development

See https://github.com/nandoflorestan/pluserable

If you would like to help make any changes to pluserable, you can run its unit tests with py.test:

py.test

To check test coverage:

py.test --cov-report term-missing --cov pluserable

The tests can also be run in parallel:

py.test -n4

We are going to use this build server: http://travis-ci.org/#!/nandoflorestan/pluserable

Origin of the project

pluserable started as a fork of horus by John Anderson: https://github.com/eventray/horus

horus is no longer maintained since 2015. pluserable is maintained and sees 1 or 2 releases per year.