def get_slant_pros_and_cons(show_progress):
# Create a new fetch index
last_fetch_index = ViewpointSection.select(fn.Max(ViewpointSection.fetch_index)).scalar() or 0
fetch_index = last_fetch_index + 1
# Get the index of the latest fetch of topics and viewpoints.
# We will only collect pros and cons for this set of topics.
viewpoint_fetch_index = Viewpoint.select(fn.Max(Viewpoint.fetch_index)).scalar() or 0
latest_viewpoint_batch = (
Viewpoint
.select()
.where(Viewpoint.fetch_index == viewpoint_fetch_index)
)
# Initialize the progress bar if requested
if show_progress:
viewpoint_count = latest_viewpoint_batch.count()
progress_bar = ProgressBar(maxval=viewpoint_count, widgets=[
'Progress: ', Percentage(),
' ', Bar(marker=RotatingMarker()),
' ', ETA(),
' Collected pros and cons for viewpoint ',
Counter(), ' / ' + str(viewpoint_count) + '.'
])
progress_bar.start()
# For every viewpoint, fetch and save all pros and cons
for viewpoint_index, viewpoint in enumerate(latest_viewpoint_batch, start=1):
# Without the format=json parameter, the Slant server will return
# HTML for the viewpoint. We get something resembling a JSON API
# response if we ask for JSON format.
response = make_request(
default_requests_session.get,
SLANT_URL + viewpoint.url_path,
params={'format': 'json'},
)
# Skip all missing responses
if response is None:
continue
results = response.json()
# If we have somehow ended up on an entry where it has an error field
# with the 404 code, something was probably wrong with the request.
# Just skip this entry and move on.
if 'error' in results and results['error'] == 404:
logger.warn("Got 404 when retrieving viewpoint with path %s.", viewpoint.url_path)
break
# Each 'section' for a view point is a pro or a con. Save a record for each one.
for section in results['sections']['children']:
ViewpointSection.create(
fetch_index=fetch_index,
viewpoint=viewpoint,
section_index=section['id'],
title=section['revision']['title'],
text=section['revision']['text'],
is_con=section['isCon'],
upvotes=section['votes']['upvotes'],
downvotes=section['votes']['downvotes'],
)
if show_progress:
progress_bar.update(viewpoint_index)
# Pause so that we don't bombard the server with requests
time.sleep(REQUEST_DELAY)
if show_progress:
progress_bar.finish()
def get_slant_topics(show_progress):
# Create a new fetch index
last_fetch_index = SlantTopic.select(fn.Max(SlantTopic.fetch_index)).scalar() or 0
fetch_index = last_fetch_index + 1
params = DEFAULT_PARAMS.copy()
first_request = True
next_url = None
count_of_processed_topics = 0
# Loop through requests to the Slant server until we reach an empty
# response or the end of the pages.
while True:
# All requests after our first one are made to a URL returned by
# the previous request. So there's a little logic here to use verbose
# parameters for the first request. They should be included by
# default in all requests after that.
if first_request:
response = make_request(
default_requests_session.get,
SLANT_TOPICS_URL,
params=params,
)
# We found that for some reason, the next page path is missing a parameter
# to specify that we still want the results of the next page as JSON.
# So we explicitly specify the format here.
else:
response = make_request(
default_requests_session.get,
next_url,
params={'format': 'json'},
)
# Leave this loop if the fetch failed
if response is None:
break
results = response.json()
# If we have somehow ended up on an entry where it has an error field
# with the 404 code, we have probably seen all results. Break out of the loop.
if 'error' in results and results['error'] == 404:
break
# If this is the first request, initialize the progress bar with
# the number of results retrieved from the results
if first_request and show_progress:
progress_bar = ProgressBar(maxval=results['count'], widgets=[
'Progress: ', Percentage(),
' ', Bar(marker=RotatingMarker()),
' ', ETA(),
' Fetched ', Counter(), ' / ' + str(results['count']) + ' topics.'
])
progress_bar.start()
for topic in results['children']:
# Each child in the list is a topic.
# Save each of these as a new topic.
topic_record = SlantTopic.create(
fetch_index=fetch_index,
topic_id=topic['uuid'],
title=topic['revision']['title'],
url_path=topic['URL'],
owner_username=topic['createdEvent']['user']['username'],
)
# A topic on Slant has a number of "viewpoints" or alternatives.
# Save each one and a URL to the site where we can visit each one.
for viewpoint in topic['viewpoints']['children']:
Viewpoint.create(
fetch_index=fetch_index,
viewpoint_index=viewpoint['id'],
title=viewpoint['revision']['title'],
topic=topic_record,
url_path=viewpoint['URL'],
)
count_of_processed_topics += 1
if show_progress:
progress_bar.update(count_of_processed_topics)
# We are also finished looping through results when there is no longer a 'next'
# page in the page properties. It's just a guess on our part that this endpoint
# will always report a next page when there is one, as there isn't an official
# API and there isn't any documentation for it.
if 'next' not in results['properties']['page']:
if show_progress:
progress_bar.finish()
break
next_page_path = results['properties']['page']['next']
next_url = SLANT_URL + next_page_path
# Pause so that we don't bombard the server with requests
time.sleep(REQUEST_DELAY)
# Reset the flag that cues us to take actions for the first request
first_request = False
