+ Requires one argument, ``context``, which should be a dictionary-like data
+ structure and must contain the following keys:
+
+ ``paginator``
+ A ``Paginator`` or ``QuerySetPaginator`` object.
+
+ ``page_obj``
+ This should be the result of calling the page method on the
+ aforementioned ``Paginator`` or ``QuerySetPaginator`` object, given
+ the current page.
+
+ This same ``context`` dictionary-like data structure may also include:
+
+ ``getvars``
+ A dictionary of all of the **GET** parameters in the current request.
+ This is useful to maintain certain types of state, even when requesting
+ a different page.
+ """
+ try:
+ paginator = context['paginator']
+ page_obj = context['page_obj']
+ page_range = paginator.page_range
+ # First and last are simply the first *n* pages and the last *n* pages,
+ # where *n* is the current window size.
+ first = set(page_range[:window])
+ last = set(page_range[-window:])
+ # Now we look around our current page, making sure that we don't wrap
+ # around.
+ current_start = page_obj.number-1-window
+ if current_start < 0:
+ current_start = 0
+ current_end = page_obj.number-1+window
+ if current_end < 0:
+ current_end = 0
+ current = set(page_range[current_start:current_end])
+ pages = []
+ # If there's no overlap between the first set of pages and the current
+ # set of pages, then there's a possible need for elusion.
+ if len(first.intersection(current)) == 0:
+ first_list = sorted(list(first))
+ second_list = sorted(list(current))
+ pages.extend(first_list)
+ diff = second_list[0] - first_list[-1]
+ # If there is a gap of two, between the last page of the first
+ # set and the first page of the current set, then we're missing a
+ # page.
+ if diff == 2:
+ pages.append(second_list[0] - 1)
+ # If the difference is just one, then there's nothing to be done,
+ # as the pages need no elusion and are correct.
+ elif diff == 1:
+ pass
+ # Otherwise, there's a bigger gap which needs to be signaled for
+ # elusion, by pushing a None value to the page list.
+ else:
+ pages.append(None)
+ pages.extend(second_list)
+ else:
+ pages.extend(sorted(list(first.union(current))))
+ # If there's no overlap between the current set of pages and the last
+ # set of pages, then there's a possible need for elusion.
+ if len(current.intersection(last)) == 0:
+ second_list = sorted(list(last))
+ diff = second_list[0] - pages[-1]
+ # If there is a gap of two, between the last page of the current
+ # set and the first page of the last set, then we're missing a
+ # page.
+ if diff == 2:
+ pages.append(second_list[0] - 1)
+ # If the difference is just one, then there's nothing to be done,
+ # as the pages need no elusion and are correct.
+ elif diff == 1:
+ pass
+ # Otherwise, there's a bigger gap which needs to be signaled for
+ # elusion, by pushing a None value to the page list.
+ else:
+ pages.append(None)
+ pages.extend(second_list)
+ else:
+ pages.extend(sorted(list(last.difference(current))))
+ to_return = {
+ 'pages': pages,
+ 'page_obj': page_obj,
+ 'paginator': paginator,
+ 'is_paginated': paginator.count > paginator.per_page,
+ }
+ if 'request' in context:
+ getvars = context['request'].GET.copy()
+ if 'page' in getvars:
+ del getvars['page']
+ if len(getvars.keys()) > 0:
+ to_return['getvars'] = "&%s" % getvars.urlencode()
+ else:
+ to_return['getvars'] = ''
+ return to_return
+ except KeyError:
+ return {}