def prev(self):
if self.current_page is None:
raise DbapiError('Can not go back more, at first page')
if self.page_index == 0:
# At the beginning of the current page, move to next...
self.current_page = self.page_iterator.prev()
self.page_index = len(self.current_page)
if self.page_index == 0:
raise DbapiError('No more items')
self.page_index -= 1
self.count -= 1
return self.current_page[self.page_index]
def prev(self):
if self.prev_cursor == 0:
raise DbapiError('Can not page back more, at first page')
data, self.next_cursor, self.prev_cursor = self.method(
cursor=self.prev_cursor, *self.args, **self.kargs)
self.count -= 1
return data
def __init__(self, method, *args, **kargs):
if hasattr(method, 'pagination_mode'):
if method.pagination_mode == 'cursor':
self.iterator = CursorIterator(method, args, kargs)
else:
self.iterator = PageIterator(method, args, kargs)
else:
raise DbapiError('This method does not perform pagination')
def build_parameters(self, args, kargs):
self.parameters = {}
for idx, arg in enumerate(args):
if arg is None:
continue
try:
self.parameters[self.allowed_param[idx]] = convert_to_utf8_str(arg)
except IndexError:
raise DbapiError('Too many parameters supplied!')
for k, arg in kargs.items():
if arg is None:
continue
if k in self.parameters:
raise DbapiError('Multiple values for parameter %s supplied!' % k)
self.parameters[k] = convert_to_utf8_str(arg)
def execute(self, method):
"""generate mongodb requests and returns model objects
This function is a combination of Dbapi's http-request and parse().
"""
method.api.clear()
try:
if method.payload_type is None: return
model = getattr(self.model_factory, method.payload_type)
except AttributeError:
raise DbapiError('No model for this payload type: %s' %
method.payload_type)
#@todo critical!: how to avoid dumps+loads while still remain
#invoking parse()?
#@todo-fixed: seems no need to fix now!
payload = self.json_lib.dumps(
model.handler(method.path, method.api, method.parameters))
return self.parse(method, payload)
def parse(self, method, payload):
try:
if method.payload_type is None: return
model = getattr(self.model_factory, method.payload_type)
except AttributeError:
raise DbapiError('No model for this payload type: %s' %
method.payload_type)
json = JSONParser.parse(self, method, payload)
if isinstance(json, tuple):
json, cursors = json
else:
cursors = None
if method.payload_list:
result = model.parse_list(method.api, json)
else:
result = model.parse(method.api, json)
if cursors:
return result, cursors
else:
return result
def parse(self, method, payload):
try:
json = self.json_lib.loads(payload)
except Exception, e:
raise DbapiError('Failed to parse JSON payload: %s' % e)
def prev(self):
if (self.current_page == 1):
raise DbapiError('Can not page back more, at first page')
self.current_page -= 1
return self.method(page=self.current_page, *self.args, **self.kargs)