a.user.id,

            (profiles_by_attendee[a].attendee_name()

                if a in profiles_by_attendee else ""),

            a.user.email,

            a.has_registered > 0,

        ])

    # Sort by whether they've registered, then ID.

    data.sort(key=lambda a: (-a[3], a[0]))

    return AttendeeListReport("Attendees", headings, data, link_view=attendee)

ProfileForm = forms.model_fields_form_factory(AttendeeProfile)

@report_view(

    "Attendees By Product/Category",

    form_type=forms.mix_form(

        forms.ProductAndCategoryForm, ProfileForm, forms.GroupByForm

    ),

)

def attendee_data(request, form, user_id=None):

    ''' Lists attendees for a given product/category selection along with

    profile data.'''

    status_display = {

        commerce.Cart.STATUS_ACTIVE: "Unpaid",

        commerce.Cart.STATUS_PAID: "Paid",

        commerce.Cart.STATUS_RELEASED: "Refunded",

    }

    output = []

    by_category = form.cleaned_data["group_by"] == forms.GroupByForm.GROUP_BY_CATEGORY

    products = form.cleaned_data["product"]

    categories = form.cleaned_data["category"]

    fields = form.cleaned_data["fields"]

    name_field = AttendeeProfile.name_field()

    items = commerce.ProductItem.objects.filter(

        Q(product__in=products) | Q(product__category__in=categories),

    ).exclude(

        cart__status=commerce.Cart.STATUS_RELEASED

    ).select_related(

        "cart", "cart__user", "product", "product__category",

    ).order_by("cart__status")

    # Make sure we select all of the related fields

    related_fields = set(

        field for field in fields

        if isinstance(AttendeeProfile._meta.get_field(field), RelatedField)

    )

    # Get all of the relevant attendee profiles in one hit.

    profiles = AttendeeProfile.objects.filter(

        attendee__user__cart__productitem__in=items

    ).select_related("attendee__user").prefetch_related(*related_fields)

    by_user = {}

    for profile in profiles:

        by_user[profile.attendee.user] = profile

    cart = "attendee__user__cart"

    cart_status = cart + "__status"

    product = cart + "__productitem__product"

    product_name = product + "__name"

    category = product + "__category"

    category_name = category + "__name"

    if by_category:

        grouping_fields = (category, category_name)

        order_by = (category, )

        first_column = "Category"

        group_name = lambda i: "%s" % (i[category_name], )

    else:

        grouping_fields = (product, product_name, category_name)

        order_by = (category, )

        first_column = "Product"

        group_name = lambda i: "%s - %s" % (i[category_name], i[product_name])

    # Group the responses per-field.

    for field in fields:

        concrete_field = AttendeeProfile._meta.get_field(field)

        field_verbose = concrete_field.verbose_name

        # Render the correct values for related fields

        if field in related_fields:

            # Get all of the IDs that will appear

            all_ids = profiles.order_by(field).values(field)

            all_ids = [i[field] for i in all_ids if i[field] is not None]

            # Get all of the concrete objects for those IDs

            model = concrete_field.related_model

            all_objects = model.objects.filter(id__in=all_ids)

            all_objects_by_id = dict((i.id, i) for i in all_objects)

            # Define a function to render those IDs.