Created
September 26, 2011 23:09
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serializable paginator
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| class SerializablePaginator(object): | |
| def __init__(self, object_list, per_page, orphans=0, allow_empty_first_page=True): | |
| self.object_list = object_list | |
| self.per_page = per_page | |
| self.orphans = orphans | |
| self.allow_empty_first_page = allow_empty_first_page | |
| self._num_pages = self._count = None | |
| def validate_number(self, number): | |
| "Validates the given 1-based page number." | |
| try: | |
| number = int(number) | |
| except ValueError: | |
| raise PageNotAnInteger('That page number is not an integer') | |
| if number < 1: | |
| raise EmptyPage('That page number is less than 1') | |
| if number > self.num_pages: | |
| if number == 1 and self.allow_empty_first_page: | |
| pass | |
| else: | |
| raise EmptyPage('That page contains no results') | |
| return number | |
| def page(self, number): | |
| "Returns a Page object for the given 1-based page number." | |
| number = self.validate_number(number) | |
| bottom = (number - 1) * self.per_page | |
| top = bottom + self.per_page | |
| if top + self.orphans >= self.count: | |
| top = self.count | |
| return Page(self.object_list[bottom:top], number, self) | |
| def _get_count(self): | |
| "Returns the total number of objects, across all pages." | |
| if self._count is None: | |
| try: | |
| self._count = self.object_list.count() | |
| except (AttributeError, TypeError): | |
| # AttributeError if object_list has no count() method. | |
| # TypeError if object_list.count() requires arguments | |
| # (i.e. is of type list). | |
| self._count = len(self.object_list) | |
| return self._count | |
| count = property(_get_count) | |
| def _get_num_pages(self): | |
| "Returns the total number of pages." | |
| if self._num_pages is None: | |
| if self.count == 0 and not self.allow_empty_first_page: | |
| self._num_pages = 0 | |
| else: | |
| hits = max(1, self.count - self.orphans) | |
| self._num_pages = int(ceil(hits / float(self.per_page))) | |
| return self._num_pages | |
| num_pages = property(_get_num_pages) | |
| def _get_page_range(self): | |
| """ | |
| Returns a 1-based range of pages for iterating through within | |
| a template for loop. | |
| """ | |
| return range(1, self.num_pages + 1) | |
| page_range = property(_get_page_range) | |
| def __getstate__(self): | |
| self._get_count() | |
| self._get_num_pages() | |
| odict = self.__dict__.copy() | |
| odict['object_list'] = None | |
| #odict['model'] = self.object_list.model #one powinny być serializowane, ale nie wchodzą do memcache'a nie wiem dlaczego | |
| #odict['query'] = self.object_list.query | |
| #odict['db'] = self.object_list.db | |
| return odict | |
| # w związku z powyższym komentarzem nie ma potrzeby odtwarzać zapytania | |
| # def __setstate__(self, state): | |
| # state['object_list'] = QuerySet(state['model'], state['query'], state['db']) | |
| # del state['model'] | |
| # del state['query'] | |
| # del state['db'] | |
| # self.__dict__.update(state) |
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