Django Generic Detail View

views.py

from django.views.generic import DetailView
from .models import Customer

class CustomerDetailView(LoginRequiredMixin, DetailView):
  def _allowed_methods(self):
    return [m.upper() for m in self.http_method_names if hasattr(self, m)]
    
  @classonlymethod
  def as_view(cls, **initkwargs):
    """
    Main entry point for a request-response process.
    """
    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 get(self, request, *args, **kwargs):
    self.object = self.get_object()
    context = self.get_context_data(object=self.object)
    return self.render_to_response(context)
    
  def get_context_data(self, **kwargs):
    """
    Insert the single object into the context dict.
    """
    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(SingleObjectMixin, 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.model_name
    else:
        return None
        
  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.
    if slug is not None and (pk is None or self.query_pk_and_slug):
        slug_field = self.get_slug_field()
        queryset = queryset.filter(**{slug_field: slug})
    # If none of those are defined, it's an error.
    if pk is None and slug is None:
        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 queryset.model.DoesNotExist:
        raise Http404(_("No %(verbose_name)s found matching the query") %
                      {'verbose_name': queryset.model._meta.verbose_name})
    return obj
    
  
  def get_queryset(self):
    """
    Return the `QuerySet` that will be used to look up the object.
    Note that this method is called by the default implementation of
    `get_object` and 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.all()
    
    
  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_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>/<model_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.model_name,
                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.model_name,
                self.template_name_suffix
            ))
        # If we still haven't managed to find any template names, we should
        # re-raise the ImproperlyConfigured to alert the user.
        if not names:
            raise
    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': request
        }
    )
    return http.HttpResponseNotAllowed(self._allowed_methods())
    
    
  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)
        
  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 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,
        using=self.template_engine,
        **response_kwargs
    )