Source code for cdhweb.pages.views

import operator

from django.utils.cache import get_conditional_response
from django.views.generic import ListView, TemplateView
from django.views.generic.base import View
from django.views.generic.edit import FormMixin
from wagtail.core.models import Page
from wagtail.search.utils import parse_query_string

from cdhweb.pages.forms import SiteSearchForm


class LastModifiedMixin(View):
    """Mixin that adds last-modified timestamps to response for detail views.

    Uses Django's get_conditional_response to return a 304 if object has not
    been modified since time specified in the HTTP if-modified-since header.
    """

    # override to customize which attribute to use as modification date
    lastmodified_attr = "updated"

    def last_modified(self):
        """Get the last modified date of the view object."""
        return getattr(self.get_object(), self.lastmodified_attr)

    def dispatch(self, request, *args, **kwargs):
        response = super(LastModifiedMixin, self).dispatch(request, *args, **kwargs)

        # NOTE: remove microseconds so that comparison will pass,
        # since microseconds are not included in the last-modified header
        last_modified = self.last_modified()
        if last_modified:
            last_modified = self.last_modified().replace(microsecond=0)
            response["Last-Modified"] = last_modified.strftime(
                "%a, %d %b %Y %H:%M:%S GMT"
            )
            last_modified = last_modified.timestamp()

        return get_conditional_response(
            request, last_modified=last_modified, response=response
        )


class LastModifiedListMixin(LastModifiedMixin):
    """Mixin that adds last-modified timestamps to response for list views.

    Uses Django's get_conditional_response to return a 304 if none of the
    objects in the list have been modified since time specified in the HTTP
    if-modified-since header.
    """

    def last_modified(self):
        """Get the most recent modification date among all view objects."""
        queryset = self.get_queryset()
        if queryset.exists():
            return getattr(
                queryset.order_by(self.lastmodified_attr).reverse().first(),
                self.lastmodified_attr,
            )


class SiteSearchView(ListView, FormMixin):
    """Search across all pages on the site."""

    model = Page
    form_class = SiteSearchForm
    paginate_by = 10
    page_title = "Search"
    template_name = "cdhpages/search.html"

    def get_queryset(self):
        # get keyword query; support filters & phrase matching with double quotes
        # see https://docs.wagtail.io/en/stable/topics/search/searching.html#query-string-parsing
        q = self.request.GET.get("q", "")
        _filters, query = parse_query_string(q)  # not using these filters yet
        query.operator = "or"  # set query operator to OR (default is AND)

        # execute search; exclude unpublished pages.
        # NOTE results sorted by relevance by default; to override sort the QS
        # first and then pass order_by_relevance=false to .search()
        return self.model.objects.live().search(query)

    def get_form_kwargs(self):
        kwargs = super().get_form_kwargs()
        # use GET instead of default POST/PUT for form data
        kwargs["data"] = self.request.GET.copy()
        return kwargs

    def get_context_data(self, **kwargs):
        context = super().get_context_data(**kwargs)
        context.update({"page_title": self.page_title})
        return context


class OpenSearchDescriptionView(TemplateView):
    """Basic open search description for searching the site via browser or
    other tools."""

    # adapted from ppa-django:
    # https://github.com/Princeton-CDH/ppa-django/blob/main/ppa/archive/views.py#L629-L634

    template_name = "cdhpages/opensearch_description.xml"
    content_type = "application/opensearchdescription+xml"