Repository navigation
Expand file tree
/
Copy pathscroll_collection_proxy.py
More file actions
91 lines (70 loc) · 2.95 KB
/
Copy pathscroll_collection_proxy.py
File metadata and controls
91 lines (70 loc) · 2.95 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
# -*- coding: utf-8 -*-
"""Proxy for the Scroll API."""
import six
from intercom import HttpError
class ScrollCollectionProxy(six.Iterator):
"""A proxy to iterate over resources returned by the Scroll API."""
def __init__(self, client, resource_class, resource_name, scroll_url):
"""Initialise the proxy."""
self.client = client
# resource name
self.resource_name = resource_name
# resource class
self.resource_class = resource_class
# the original URL to retrieve the resources
self.scroll_url = scroll_url
# the identity of the scroll, extracted from the response
self.scroll_param = None
# an iterator over the resources found in the response
self.resources = None
# a link to the next page of results
self.next_page = None
def __iter__(self):
"""Return self as the proxy has __next__ implemented."""
return self
def __next__(self):
"""Return the next resource from the response."""
if self.resources is None:
# get the first page of results
self.get_first_page()
# try to get a resource if there are no more in the
# current resource iterator (StopIteration is raised)
# try to get the next page of results first
try:
resource = six.next(self.resources)
except StopIteration:
self.get_next_page()
resource = six.next(self.resources)
instance = self.resource_class(**resource)
return instance
def __getitem__(self, index):
"""Return an exact item from the proxy."""
for i in range(index):
six.next(self)
return six.next(self)
def get_first_page(self):
"""Return the first page of results."""
return self.get_page(self.scroll_param)
def get_next_page(self):
"""Return the next page of results."""
return self.get_page(self.scroll_param)
def get_page(self, scroll_param=None):
"""Retrieve a page of results from the Scroll API."""
if scroll_param is None:
response = self.client.get(self.scroll_url, {})
else:
response = self.client.get(self.scroll_url, {'scroll_param': scroll_param})
if response is None:
raise HttpError('Http Error - No response entity returned')
# create the resource iterator
collection = response[self.resource_name]
self.resources = iter(collection)
# grab the next page URL if one exists
self.scroll_param = self.extract_scroll_param(response)
def records_present(self, response):
"""Return whether there are resources in the response."""
return len(response.get(self.resource_name)) > 0
def extract_scroll_param(self, response):
"""Extract the scroll_param from the response."""
if self.records_present(response):
return response.get('scroll_param')