def __init__(self,
options,
state=None,
api_adaptor=None,
extension_name='extension_name'):
_print('init: Paginator')
if (state is None):
self.state = State()
else:
self.state = state
self.extension_name = extension_name
self.reset()
try:
self.max_pages = int(options['max_pages'])
_print('about to load formatters')
self.formatter = self.loadFormatter(options)
except Exception as ex:
_print(ex)
_print('could not initialize Paginator.')
raise
if api_adaptor is not None:
self.api_adaptor = api_adaptor
else:
_print('about to load api adaptor for extension ' +
self.extension_name)
api_adaptor_class = self.loadClass(options, 'api_adaptor')
self.api_adaptor = api_adaptor_class(options)
def test_persist():
state = State(last_item_id='4')
state.persist() #store ro disk
restored_state = State() #loads from disk
assert restored_state.last_item_id == '4'
restored_state.setLastItemId('6') #also persist
restored_second_state = State() #loads from disk
assert restored_second_state.last_item_id == '6'
def test_no_new_items():
paginator = Paginator(options=options,
api_adaptor=api_mock([first_page]),
state=State(last_item_id='1'))
paginator.next()
assert unwrap(paginator.fetchPageItems()) == None
paginator.next()
assert unwrap(paginator.fetchPageItems()) == None
def test_negative_max_pages():
paginator = Paginator(options={
**options,
**options_negative_max_page
},
api_adaptor=api_mock(two_pages),
state=State(last_item_id='5'))
is_available = paginator.next()
assert is_available == False
def test_one_item():
paginator = Paginator(options=options,
api_adaptor=api_mock([first_page]),
state=State(last_item_id='2'))
paginator.next()
assert unwrap(paginator.fetchPageItems()) == [{'id': '1'}]
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == None
def test_4_items():
paginator = Paginator(options=options,
api_adaptor=api_mock(two_pages),
state=State(last_item_id='5'))
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == first_page
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == [{'id': '4'}]
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == None
def test_state_based_pagination():
state = State()
assert state.last_item_id == ''
mocker = api_mock([first_page])
paginator = Paginator(options=options, api_adaptor=mocker, state=state)
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == first_page
mocker.setPages([second_page, first_page])
paginator.reset()
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == second_page
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == None
mocker.setPages([fourth_page, third_page, second_page, first_page])
paginator.reset()
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == fourth_page
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == third_page
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == None
mocker.setPages([fourth_page])
paginator.reset()
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == None
def test_max_pages():
paginator = Paginator(options={
**options,
**options_two_page
},
api_adaptor=api_mock(three_pages),
state=State(last_item_id='100'))
paginator.next()
items = unwrap(paginator.fetchPageItems())
assert items == first_page
is_available = paginator.next()
assert is_available == True
items = unwrap(paginator.fetchPageItems())
assert items == second_page
is_available = paginator.next()
assert is_available == False
def test_persist_invalid_path():
state = State(last_item_id='4', persit_path='/invalid_path/mock.obj')
state.persist() #should persist to disk but fails due to bad path
restored_state = State() #loads from disk
assert restored_state.last_item_id == '' #value lost - due to invalid persist path
class Paginator:
def __init__(self,
options,
state=None,
api_adaptor=None,
extension_name='extension_name'):
_print('init: Paginator')
if (state is None):
self.state = State()
else:
self.state = state
self.extension_name = extension_name
self.reset()
try:
self.max_pages = int(options['max_pages'])
_print('about to load formatters')
self.formatter = self.loadFormatter(options)
except Exception as ex:
_print(ex)
_print('could not initialize Paginator.')
raise
if api_adaptor is not None:
self.api_adaptor = api_adaptor
else:
_print('about to load api adaptor for extension ' +
self.extension_name)
api_adaptor_class = self.loadClass(options, 'api_adaptor')
self.api_adaptor = api_adaptor_class(options)
def loadClass(self, options, type_name):
_print('about to load ' + type_name + ' class...')
module_name = options[self.extension_name + '.' + type_name +
'_module']
class_name = options[self.extension_name + '.' + type_name + '_class']
_print('about to load from module:' + module_name)
_print('about to load class:' + class_name)
module = __import__(module_name, fromlist=[class_name])
_class = getattr(module, class_name)
return _class
def loadFormatter(self, options):
_print('about to load formatter for extension ' + self.extension_name)
formatter_class = self.loadClass(options, 'formatter')
formatter_class.options = options
return formatter_class
def reset(self):
try:
self.state.setLastItemId(self.current_item_id)
except:
pass
self.page_num = -1
self.current_item_id = ''
self.is_end = False
def isNextAvailable(self):
is_not_maxed = self.max_pages >= 0 and (
self.max_pages == 0 or (self.page_num + 1) < self.max_pages)
is_not_reached_end = not self.is_end
return is_not_reached_end and is_not_maxed
def next(self):
if self.isNextAvailable():
self.page_num += 1
return True
else:
return False
def filterItems(self, items):
if items is None or len(items) == 0: return None
filtered_items = []
if self.current_item_id == '':
self.current_item_id = items[0].getID()
for item in items:
if item.getID() != self.state.last_item_id:
filtered_items.append(item)
else:
#_print('Current Record ID: ' + item.getID() + ' matched last record id from state: ' + self.state.last_item_id )
self.state.setLastItemId(self.current_item_id)
self.is_end = True
break
if len(filtered_items) == 0:
return None
else:
return filtered_items
def fetchPageItems(self):
if self.is_end: return None
response_json = self.api_adaptor.fetchItems(self.page_num)
if response_json is not None:
try:
items = self.formatter.wrapItems(response_json)
except Exception as ex:
_print(ex)
items = None
return self.filterItems(items)
else:
return None