This is the repository for the online module Bots as Digital Infrapuncture, commissioned by the Utrecht University
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import functools
import logging
import os
from collections import namedtuple
from math import ceil
logger = logging.getLogger(__name__)
PaginationRule = namedtuple(
'PaginationRule',
'min_page URL SAVE_AS',
)
class Paginator:
def __init__(self, name, url, object_list, settings, per_page=None):
self.name = name
self.url = url
self.object_list = object_list
self.settings = settings
if per_page:
self.per_page = per_page
self.orphans = settings['DEFAULT_ORPHANS']
else:
self.per_page = len(object_list)
self.orphans = 0
self._num_pages = self._count = None
def page(self, number):
"Returns a Page object for the given 1-based page number."
bottom = (number - 1) * self.per_page
top = bottom + self.per_page
if top + self.orphans >= self.count:
top = self.count
return Page(self.name, self.url, self.object_list[bottom:top], number,
self, self.settings)
def _get_count(self):
"Returns the total number of objects, across all pages."
if self._count is None:
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:
hits = max(1, self.count - self.orphans)
self._num_pages = int(ceil(hits / (float(self.per_page) or 1)))
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 list(range(1, self.num_pages + 1))
page_range = property(_get_page_range)
class Page:
def __init__(self, name, url, object_list, number, paginator, settings):
self.full_name = name
self.name, self.extension = os.path.splitext(name)
dn, fn = os.path.split(name)
self.base_name = dn if fn in ('index.htm', 'index.html') else self.name
self.base_url = url
self.object_list = object_list
self.number = number
self.paginator = paginator
self.settings = settings
def __repr__(self):
return '<Page {} of {}>'.format(self.number, self.paginator.num_pages)
def has_next(self):
return self.number < self.paginator.num_pages
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):
return self.number + 1
def previous_page_number(self):
return self.number - 1
def start_index(self):
"""
Returns the 1-based index of the first object on this page,
relative to total objects in the paginator.
"""
# Special case, return zero if no items.
if self.paginator.count == 0:
return 0
return (self.paginator.per_page * (self.number - 1)) + 1
def end_index(self):
"""
Returns the 1-based index of the last object on this page,
relative to total objects found (hits).
"""
# Special case for the last page because there can be orphans.
if self.number == self.paginator.num_pages:
return self.paginator.count
return self.number * self.paginator.per_page
def _from_settings(self, key):
"""Returns URL information as defined in settings. Similar to
URLWrapper._from_settings, but specialized to deal with pagination
logic."""
rule = None
# find the last matching pagination rule
for p in self.settings['PAGINATION_PATTERNS']:
if p.min_page <= self.number:
rule = p
if not rule:
return ''
prop_value = getattr(rule, key)
if not isinstance(prop_value, str):
logger.warning('%s is set to %s', key, prop_value)
return prop_value
# URL or SAVE_AS is a string, format it with a controlled context
context = {
'save_as': self.full_name,
'url': self.base_url,
'name': self.name,
'base_name': self.base_name,
'extension': self.extension,
'number': self.number,
}
ret = prop_value.format(**context)
# Remove a single leading slash, if any. This is done for backwards
# compatibility reasons. If a leading slash is needed (for URLs
# relative to server root or absolute URLs without the scheme such as
# //blog.my.site/), it can be worked around by prefixing the pagination
# pattern by an additional slash (which then gets removed, preserving
# the other slashes). This also means the following code *can't* be
# changed to lstrip() because that would remove all leading slashes and
# thus make the workaround impossible. See
# test_custom_pagination_pattern() for a verification of this.
if ret[0] == '/':
ret = ret[1:]
return ret
url = property(functools.partial(_from_settings, key='URL'))
save_as = property(functools.partial(_from_settings, key='SAVE_AS'))