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Explain ILIAS HTML parsing and add some warnings

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This commit is contained in:
I-Al-Istannen 2021-05-23 18:12:51 +02:00
parent 463f8830d7
commit 59f13bb8d6
2 changed files with 37 additions and 23 deletions
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58
PFERD/crawlers/ilias/kit_ilias_html.py
View File

@ -8,6 +8,7 @@ from urllib.parse import urljoin, urlparse
from bs4 import BeautifulSoup, Tag
from PFERD.logging import log
from PFERD.utils import url_set_query_params
TargetType = Union[str, int]
@ -48,11 +49,15 @@ class IliasPage:
Return all child page elements you can find here.
"""
if self._is_video_player():
log.explain("Page is a video player, extracting URL")
return self._player_to_video()
if self._is_video_listing():
log.explain("Page is a video listing, finding elements")
return self._find_video_entries()
if self._is_exercise_file():
log.explain("Page is an exercise, finding elements")
return self._find_exercise_entries()
log.explain("Page is a normal folder, finding elements")
return self._find_normal_entries()
def _is_video_player(self) -> bool:
@ -96,7 +101,7 @@ class IliasPage:
json_match = regex.search(str(self._soup))
if json_match is None:
print(f"Could not find json stream info for {self._page_url!r}")
log.warn("Could not find JSON stream info in video player. Ignoring video.")
return []
json_str = json_match.group(1)
@ -125,6 +130,7 @@ class IliasPage:
url: str = self._abs_url_from_link(content_link)
query_params = {"limit": "800", "cmd": "asyncGetTableGUI", "cmdMode": "asynch"}
url = url_set_query_params(url, query_params)
log.explain("Found ILIAS redirection page, following it as a new entry")
return [IliasPageElement(IliasElementType.VIDEO_FOLDER_MAYBE_PAGINATED, url, "")]
is_paginated = self._soup.find(id=re.compile(r"tab_page_sel.+")) is not None
@ -139,20 +145,12 @@ class IliasPage:
table_element: Tag = self._soup.find(name="table", id=re.compile(r"tbl_xoct_.+"))
if table_element is None:
# TODO: Properly log this
print(
"Could not increase elements per page (table not found)."
" Some might not be crawled!"
)
log.warn("Couldn't increase elements per page (table not found). I might miss elements.")
return self._find_video_entries_no_paging()
id_match = re.match(r"tbl_xoct_(.+)", table_element.attrs["id"])
if id_match is None:
# TODO: Properly log this
print(
"Could not increase elements per page (table id not found)."
" Some might not be crawled!"
)
log.warn("Couldn't increase elements per page (table id not found). I might miss elements.")
return self._find_video_entries_no_paging()
table_id = id_match.group(1)
@ -160,6 +158,8 @@ class IliasPage:
query_params = {f"tbl_xoct_{table_id}_trows": "800",
"cmd": "asyncGetTableGUI", "cmdMode": "asynch"}
url = url_set_query_params(self._page_url, query_params)
log.explain("Disabled pagination, retrying folder as a new entry")
return [IliasPageElement(IliasElementType.VIDEO_FOLDER, url, "")]
def _find_video_entries_no_paging(self) -> List[IliasPageElement]:
@ -173,7 +173,6 @@ class IliasPage:
results: List[IliasPageElement] = []
# TODO: Sadly the download button is currently broken, so never do that
for link in video_links:
results.append(self._listed_video_to_element(link))
@ -194,6 +193,7 @@ class IliasPage:
video_url = self._abs_url_from_link(link)
log.explain(f"Found video {video_name!r} at {video_url!r}")
return IliasPageElement(IliasElementType.VIDEO_PLAYER, video_url, video_name, modification_time)
def _find_exercise_entries(self) -> List[IliasPageElement]:
@ -213,6 +213,8 @@ class IliasPage:
text="Download"
)
log.explain(f"Found exercise container {container_name!r}")
# Grab each file as you now have the link
for file_link in files:
# Two divs, side by side. Left is the name, right is the link ==> get left
@ -221,6 +223,7 @@ class IliasPage:
file_name = _sanitize_path_name(file_name)
url = self._abs_url_from_link(file_link)
log.explain(f"Found exercise entry {file_name!r}")
results.append(IliasPageElement(
IliasElementType.FILE,
url,
@ -245,11 +248,14 @@ class IliasPage:
if not element_type:
continue
if element_type == IliasElementType.MEETING:
element_name = _sanitize_path_name(self._normalize_meeting_name(element_name))
normalized = _sanitize_path_name(self._normalize_meeting_name(element_name))
log.explain(f"Normalized meeting name from {element_name!r} to {normalized!r}")
element_name = normalized
elif element_type == IliasElementType.FILE:
result.append(self._file_to_element(element_name, abs_url, link))
continue
log.explain(f"Found {element_name!r}")
result.append(IliasPageElement(element_type, abs_url, element_name, description=description))
return result
@ -282,8 +288,8 @@ class IliasPage:
)
if modification_date_match is None:
modification_date = None
# TODO: Properly log this
print(f"Could not extract start date from {all_properties_text!r}")
# TODO: Figure out if this is expected or *always* an error.
log.explain(f"Element {name} at {url} has no date. Properties: {all_properties_text!r}")
else:
modification_date_str = modification_date_match.group(1)
modification_date = demangle_date(modification_date_str)
@ -292,6 +298,7 @@ class IliasPage:
name = _sanitize_path_name(link_element.getText())
full_path = name + "." + file_type
log.explain(f"Found file {full_path!r}")
return IliasPageElement(IliasElementType.FILE, url, full_path, modification_date)
@staticmethod
@ -318,8 +325,10 @@ class IliasPage:
if "ref_id=" in parsed_url.query:
return IliasPage._find_type_from_folder_like(link_element, url)
# TODO: Log this properly
print(f"Unknown type: The element was at {str(element_name)!r} and it is {link_element!r})")
_unexpected_html_warning()
log.warn_contd(
f"Tried to figure out element type, but failed for {str(element_name)!r} / {link_element!r})"
)
return None
@staticmethod
@ -339,16 +348,16 @@ class IliasPage:
break
if found_parent is None:
# TODO: Log this properly
print(f"Could not find element icon for {url!r}")
_unexpected_html_warning()
log.warn_contd(f"Tried to figure out element type, but did not find an icon for {url!r}")
return None
# Find the small descriptive icon to figure out the type
img_tag: Optional[Tag] = found_parent.select_one("img.ilListItemIcon")
if img_tag is None:
# TODO: Log this properly
print(f"Could not find image tag for {url!r}")
_unexpected_html_warning()
log.warn_contd(f"Tried to figure out element type, but did not find an image for {url!r}")
return None
if "opencast" in str(img_tag["alt"]).lower():
@ -393,6 +402,10 @@ class IliasPage:
return urljoin(self._page_url, link_tag.get("href"))
def _unexpected_html_warning() -> None:
log.warn("Encountered unexpected HTML structure, ignoring element.")
german_months = ['Jan', 'Feb', 'Mär', 'Apr', 'Mai', 'Jun', 'Jul', 'Aug', 'Sep', 'Okt', 'Nov', 'Dez']
english_months = ['Jan', 'Feb', 'Mar', 'Apr', 'May', 'Jun', 'Jul', 'Aug', 'Sep', 'Oct', 'Nov', 'Dec']
@ -429,8 +442,7 @@ def demangle_date(date_str: str) -> Optional[datetime]:
return datetime(year, month, day, hour, minute)
except Exception:
# TODO: Properly log this
print(f"Could not parse date {date_str!r}")
log.warn(f"Date parsing failed for {date_str!r}")
return None

2
PFERD/crawlers/ilias/kit_ilias_web_crawler.py
View File

@ -229,6 +229,8 @@ class KitIliasWebCrawler(HttpCrawler):
elements.clear()
async with cl:
soup = await self._get_page(url)
log.explain_topic(f"Parsing HTML page for {path!r}")
log.explain(f"URL: {url!r}")
page = IliasPage(soup, url, parent)
elements.extend(page.get_child_elements())