classify 0.5.0

Installation

$ pip install classify

Usage

$ classify <python.path.to.Class>

This outputs by default to your shell’s pager. However you can also generate an HTML document to get CCBV style pages and even serve that document.

By default HTML documents are saved to /path/to/current/dir/output. To change this specify a relative location with the --output option.

$ classify <python.path.to.Class> --html [--output [--serve [--port]]]

Why?

CCBV has long been part of my everyday toolkit for working with Django’s class-based views, it’s a fantastic resource for quick reference. But it only covers Django’s CBVs.

Classify aims to be CCBV for all your Python classes.

An Example

$ classify django.views.generic.CreateView

class CreateView(SingleObjectTemplateResponseMixin, BaseCreateView):
    """
    View for creating a new object instance,
    with a response rendered by template.
    """
    content_type = None
    context_object_name = None
    form_class = None
    http_method_names = [u'get', u'post', u'put', u'delete', u'head', u'options', u'trace']
    initial = {}
    model = None
    pk_url_kwarg = pk
    queryset = None
    response_class = <class 'django.template.response.TemplateResponse'>
    slug_field = slug
    slug_url_kwarg = slug
    success_url = None
    template_name = None
    template_name_field = None
    template_name_suffix = _form

    def __init__(self, **kwargs):
        """
        Constructor. Called in the URLconf; can contain helpful extra
        keyword arguments, and other things.
        """
        # Go through keyword arguments, and either save their values to our
        # instance, or raise an error.
        for key, value in six.iteritems(kwargs):
            setattr(self, key, value)

    @classonlymethod
    def as_view(cls, **initkwargs):
        """
        Main entry point for a request-response process.
        """
        # sanitize keyword arguments
        for key in initkwargs:
            if key in cls.http_method_names:
                raise TypeError("You tried to pass in the %s method name as a "
                                "keyword argument to %s(). Don't do that."
                                % (key, cls.__name__))
            if not hasattr(cls, key):
                raise TypeError("%s() received an invalid keyword %r. as_view "
                                "only accepts arguments that are already "
                                "attributes of the class." % (cls.__name__, key))

        def view(request, *args, **kwargs):
            self = cls(**initkwargs)
            if hasattr(self, 'get') and not hasattr(self, 'head'):
                self.head = self.get
            self.request = request
            self.args = args
            self.kwargs = kwargs
            return self.dispatch(request, *args, **kwargs)

        # take name and docstring from class
        update_wrapper(view, cls, updated=())

        # and possible attributes set by decorators
        # like csrf_exempt from dispatch
        update_wrapper(view, cls.dispatch, assigned=())
        return view

    def dispatch(self, request, *args, **kwargs):
        # Try to dispatch to the right method; if a method doesn't exist,
        # defer to the error handler. Also defer to the error handler if the
        # request method isn't on the approved list.
        if request.method.lower() in self.http_method_names:
            handler = getattr(self, request.method.lower(), self.http_method_not_allowed)
        else:
            handler = self.http_method_not_allowed
        return handler(request, *args, **kwargs)

    def form_invalid(self, form):
        """
        If the form is invalid, re-render the context data with the
        data-filled form and errors.
        """
        return self.render_to_response(self.get_context_data(form=form))

    def form_valid(self, form):
        """
        If the form is valid, redirect to the supplied URL.
        """
        return HttpResponseRedirect(self.get_success_url())

    def form_valid(self, form):
        """
        If the form is valid, save the associated model.
        """
        self.object = form.save()
        return super(ModelFormMixin, self).form_valid(form)

    def get(self, request, *args, **kwargs):
        """
        Handles GET requests and instantiates a blank version of the form.
        """
        form_class = self.get_form_class()
        form = self.get_form(form_class)
        return self.render_to_response(self.get_context_data(form=form))

    def get(self, request, *args, **kwargs):
        self.object = None
        return super(BaseCreateView, self).get(request, *args, **kwargs)

    def get_context_data(self, **kwargs):
        if 'view' not in kwargs:
            kwargs['view'] = self
        return kwargs

    def get_context_data(self, **kwargs):
        """
        Insert the single object into the context dict.
        """
        context = {}
        context_object_name = self.get_context_object_name(self.object)
        if context_object_name:
            context[context_object_name] = self.object
        context.update(kwargs)
        return super(SingleObjectMixin, self).get_context_data(**context)

    def get_context_data(self, **kwargs):
        """
        If an object has been supplied, inject it into the context with the
        supplied context_object_name name.
        """
        context = {}
        if self.object:
            context['object'] = self.object
            context_object_name = self.get_context_object_name(self.object)
            if context_object_name:
                context[context_object_name] = self.object
        context.update(kwargs)
        return super(ModelFormMixin, self).get_context_data(**context)

    def get_context_object_name(self, obj):
        """
        Get the name to use for the object.
        """
        if self.context_object_name:
            return self.context_object_name
        elif isinstance(obj, models.Model):
            return obj._meta.object_name.lower()
        else:
            return None

    def get_form(self, form_class):
        """
        Returns an instance of the form to be used in this view.
        """
        return form_class(**self.get_form_kwargs())

    def get_form_class(self):
        """
        Returns the form class to use in this view
        """
        return self.form_class

    def get_form_class(self):
        """
        Returns the form class to use in this view.
        """
        if self.form_class:
            return self.form_class
        else:
            if self.model is not None:
                # If a model has been explicitly provided, use it
                model = self.model
            elif hasattr(self, 'object') and self.object is not None:
                # If this view is operating on a single object, use
                # the class of that object
                model = self.object.__class__
            else:
                # Try to get a queryset and extract the model class
                # from that
                model = self.get_queryset().model
            return model_forms.modelform_factory(model)

    def get_form_kwargs(self):
        """
        Returns the keyword arguments for instantiating the form.
        """
        kwargs = {'initial': self.get_initial()}
        if self.request.method in ('POST', 'PUT'):
            kwargs.update({
                'data': self.request.POST,
                'files': self.request.FILES,
            })
        return kwargs

    def get_form_kwargs(self):
        """
        Returns the keyword arguments for instantiating the form.
        """
        kwargs = super(ModelFormMixin, self).get_form_kwargs()
        kwargs.update({'instance': self.object})
        return kwargs

    def get_initial(self):
        """
        Returns the initial data to use for forms on this view.
        """
        return self.initial.copy()

    def get_object(self, queryset=None):
        """
        Returns the object the view is displaying.

        By default this requires `self.queryset` and a `pk` or `slug` argument
        in the URLconf, but subclasses can override this to return any object.
        """
        # Use a custom queryset if provided; this is required for subclasses
        # like DateDetailView
        if queryset is None:
            queryset = self.get_queryset()

        # Next, try looking up by primary key.
        pk = self.kwargs.get(self.pk_url_kwarg, None)
        slug = self.kwargs.get(self.slug_url_kwarg, None)
        if pk is not None:
            queryset = queryset.filter(pk=pk)

        # Next, try looking up by slug.
        elif slug is not None:
            slug_field = self.get_slug_field()
            queryset = queryset.filter(**{slug_field: slug})

        # If none of those are defined, it's an error.
        else:
            raise AttributeError("Generic detail view %s must be called with "
                                 "either an object pk or a slug."
                                 % self.__class__.__name__)

        try:
            # Get the single item from the filtered queryset
            obj = queryset.get()
        except ObjectDoesNotExist:
            raise Http404(_("No %(verbose_name)s found matching the query") %
                          {'verbose_name': queryset.model._meta.verbose_name})
        return obj

    def get_queryset(self):
        """
        Get the queryset to look an object up against. May not be called if
        `get_object` is overridden.
        """
        if self.queryset is None:
            if self.model:
                return self.model._default_manager.all()
            else:
                raise ImproperlyConfigured("%(cls)s is missing a queryset. Define "
                                           "%(cls)s.model, %(cls)s.queryset, or override "
                                           "%(cls)s.get_queryset()." % {
                                                'cls': self.__class__.__name__
                                        })
        return self.queryset._clone()

    def get_slug_field(self):
        """
        Get the name of a slug field to be used to look up by slug.
        """
        return self.slug_field

    def get_success_url(self):
        """
        Returns the supplied success URL.
        """
        if self.success_url:
            # Forcing possible reverse_lazy evaluation
            url = force_text(self.success_url)
        else:
            raise ImproperlyConfigured(
                "No URL to redirect to. Provide a success_url.")
        return url

    def get_success_url(self):
        """
        Returns the supplied URL.
        """
        if self.success_url:
            url = self.success_url % self.object.__dict__
        else:
            try:
                url = self.object.get_absolute_url()
            except AttributeError:
                raise ImproperlyConfigured(
                    "No URL to redirect to.  Either provide a url or define"
                    " a get_absolute_url method on the Model.")
        return url

    def get_template_names(self):
        """
        Returns a list of template names to be used for the request. Must return
        a list. May not be called if render_to_response is overridden.
        """
        if self.template_name is None:
            raise ImproperlyConfigured(
                "TemplateResponseMixin requires either a definition of "
                "'template_name' or an implementation of 'get_template_names()'")
        else:
            return [self.template_name]

    def get_template_names(self):
        """
        Return a list of template names to be used for the request. May not be
        called if render_to_response is overridden. Returns the following list:

        * the value of ``template_name`` on the view (if provided)
        * the contents of the ``template_name_field`` field on the
          object instance that the view is operating upon (if available)
        * ``<app_label>/<object_name><template_name_suffix>.html``
        """
        try:
            names = super(SingleObjectTemplateResponseMixin, self).get_template_names()
        except ImproperlyConfigured:
            # If template_name isn't specified, it's not a problem --
            # we just start with an empty list.
            names = []

        # If self.template_name_field is set, grab the value of the field
        # of that name from the object; this is the most specific template
        # name, if given.
        if self.object and self.template_name_field:
            name = getattr(self.object, self.template_name_field, None)
            if name:
                names.insert(0, name)

        # The least-specific option is the default <app>/<model>_detail.html;
        # only use this if the object in question is a model.
        if isinstance(self.object, models.Model):
            names.append("%s/%s%s.html" % (
                self.object._meta.app_label,
                self.object._meta.object_name.lower(),
                self.template_name_suffix
            ))
        elif hasattr(self, 'model') and self.model is not None and issubclass(self.model, models.Model):
            names.append("%s/%s%s.html" % (
                self.model._meta.app_label,
                self.model._meta.object_name.lower(),
                self.template_name_suffix
            ))
        return names

    def http_method_not_allowed(self, request, *args, **kwargs):
        logger.warning('Method Not Allowed (%s): %s', request.method, request.path,
            extra={
                'status_code': 405,
                'request': self.request
            }
        )
        return http.HttpResponseNotAllowed(self._allowed_methods())

    def options(self, request, *args, **kwargs):
        """
        Handles responding to requests for the OPTIONS HTTP verb.
        """
        response = http.HttpResponse()
        response['Allow'] = ', '.join(self._allowed_methods())
        response['Content-Length'] = '0'
        return response

    def post(self, request, *args, **kwargs):
        """
        Handles POST requests, instantiating a form instance with the passed
        POST variables and then checked for validity.
        """
        form_class = self.get_form_class()
        form = self.get_form(form_class)
        if form.is_valid():
            return self.form_valid(form)
        else:
            return self.form_invalid(form)

    def post(self, request, *args, **kwargs):
        self.object = None
        return super(BaseCreateView, self).post(request, *args, **kwargs)

    def put(self, *args, **kwargs):
        return self.post(*args, **kwargs)

    def render_to_response(self, context, **response_kwargs):
        """
        Returns a response, using the `response_class` for this
        view, with a template rendered with the given context.

        If any keyword arguments are provided, they will be
        passed to the constructor of the response class.
        """
        response_kwargs.setdefault('content_type', self.content_type)
        return self.response_class(
            request = self.request,
            template = self.get_template_names(),
            context = context,
            **response_kwargs
        )