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#!/usr/bin/env python
# -*- encoding: utf-8 -*-
from . import base
from .link import Link
class Method(base.Method):
""" Lazy and cache support """
def cached(func):
""" Decorator to don't do a request if it's cached """
def wrapper(self, page=1):
if str(page) in self.cache:
return self.cache[str(page)]
return func(self, page)
return wrapper
def if_needs_lastpage(func):
""" Decorator to set last page only if it can and it hasn't retrieved
before """
def wrapper(self, has_link):
has_last_page = hasattr(self, 'last_page')
if not has_last_page and has_link:
return func(self, has_link)
elif not has_last_page and not has_link:
self.last_page = 1
return wrapper
@if_needs_lastpage
def __set_last_page_from(self, link_header):
""" Get and set last_page form link header """
link = Link(link_header)
self.last_page = int(link.last.params.get('page'))
@cached
def __call__(self, page=1):
""" Call a real request """
response = self.method(page=page)
self.__set_last_page_from(response.headers.get('link'))
self.cache[str(page)] = self.resource.loads(response.content)
return self.cache[str(page)]
@property
def last(self):
if not hasattr(self, 'last_page'):
self()
return self.last_page
class Result(base.Result):
"""
It's a very **lazy** paginator beacuse only do a real request
when is needed, besides it's **cached**, so never repeats a request.
You have several ways to consume it
#. Iterating over the result::
result = some_request()
for page in result:
for resource in page:
print resource
#. With a generator::
result = some_request()
for resource in result.iterator():
print resource
#. As a list::
result = some_request()
print result.all()
#. Also you can request some page manually
Each ``Page`` is an iterator and contains resources::
result = some_request()
assert result.pages > 3
page3 = result.get_page(3)
page3_resources = list(page3)
"""
def __init__(self, method):
super(Result, self).__init__(method)
self.page = base.Page(self.getter)
def __next__(self):
if self.page <= self.pages:
page_to_return = self.page
self.page = base.Page(self.getter, page_to_return + 1)
return page_to_return
self.page = base.Page(self.getter)
raise StopIteration
@property
def pages(self):
""" Total number of pages in request """
return self.getter.last
def get_page(self, page):
""" Get ``Page`` of resources
:param int page: Page number
"""
if page in xrange(1, self.pages + 1):
return base.Page(self.getter, page)
return None
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