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countless django paginator for django-rest-framework
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| import collections | |
| from django.utils import six | |
| from django.core.paginator import PageNotAnInteger, EmptyPage | |
| class Paginator(object): | |
| def __init__(self, object_list, per_page, orphans=0, | |
| allow_empty_first_page=True): | |
| self.object_list = object_list | |
| self.per_page = int(per_page) | |
| self.orphans = int(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 (TypeError, ValueError): | |
| raise PageNotAnInteger('That page number is not an integer') | |
| if number < 1: | |
| raise EmptyPage('That page number is less than 1') | |
| 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 | |
| return Page(self.object_list[bottom:top + 1], number, self) | |
| class Page(collections.Sequence): | |
| def __init__(self, object_list, number, paginator): | |
| object_length = len(object_list) | |
| if object_length > paginator.per_page: | |
| self.object_list = object_list[:object_length - 1] | |
| self._has_next = True | |
| else: | |
| self.object_list = object_list | |
| self._has_next = False | |
| # force evaluate queryset to get rid of all function | |
| # since DRF checks it and then call with queryset.all | |
| # which will hit db due to different queryset | |
| self.object_list = list(object_list) | |
| self.number = number | |
| self.paginator = paginator | |
| def __repr__(self): | |
| return '<Page %s of N/A>' % (self.number,) | |
| def __len__(self): | |
| return len(self.object_list) | |
| def __getitem__(self, index): | |
| if not isinstance(index, (slice,) + six.integer_types): | |
| raise TypeError | |
| # The object_list is converted to a list so that if it was a QuerySet | |
| # it won't be a database hit per __getitem__. | |
| if not isinstance(self.object_list, list): | |
| self.object_list = list(self.object_list) | |
| return self.object_list[index] | |
| def has_next(self): | |
| return self._has_next | |
| def has_previous(self): | |
| return self.number > 1 | |
| def has_other_pages(self): | |
| return self.has_previous() or self.has_next() | |
| def next_page_number(self): | |
| if not self._has_next: | |
| if self.number == 1 and self.allow_empty_first_page: | |
| pass | |
| else: | |
| raise EmptyPage('That page contains no results') | |
| return self.number + 1 | |
| def previous_page_number(self): | |
| if self.number < 1: | |
| raise EmptyPage('That page number is less than 1') | |
| return self.number - 1 |
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