Unwrap future meetings when ILIAS hides them behind a pagination

PFERD/crawl/ilias/kit_ilias_html.py

@@ -146,11 +146,17 @@ class IliasPage:
         if self._is_forum_page():
             if "trows=800" in self._page_url:
                 return None
+            log.explain("Requesting *all* forum threads")
             return self._get_show_max_forum_entries_per_page_url()
         if self._is_ilias_opencast_embedding():
+            log.explain("Unwrapping opencast embedding")
             return self.get_child_elements()[0]
         if self._page_type == IliasElementType.VIDEO_FOLDER_MAYBE_PAGINATED:
+            log.explain("Unwrapping video pagination")
             return self._find_video_entries_paginated()[0]
+        if self._contains_collapsed_future_meetings():
+            log.explain("Requesting *all* future meetings")
+            return self._uncollapse_future_meetings_url()
         return None
 
     def _is_forum_page(self) -> bool:
@@ -203,6 +209,16 @@ class IliasPage:
             return False
         return "target=copa_" in link.get("value")
 
+    def _contains_collapsed_future_meetings(self) -> bool:
+        return self._uncollapse_future_meetings_url() is not None
+
+    def _uncollapse_future_meetings_url(self) -> Optional[IliasPageElement]:
+        element = self._soup.find("a", attrs={"href": lambda x: x and "crs_next_sess=1" in x})
+        if not element:
+            return None
+        link = self._abs_url_from_link(element)
+        return IliasPageElement(IliasElementType.FOLDER, link, "show all meetings")
+
     def _player_to_video(self) -> List[IliasPageElement]:
         # Fetch the actual video page. This is a small wrapper page initializing a javscript
         # player. Sadly we can not execute that JS. The actual video stream url is nowhere
@@ -793,6 +809,10 @@ class IliasPage:
         if img_tag is None:
             img_tag = found_parent.select_one("img.icon")
 
+        if img_tag is None and found_parent.find("a", attrs={"href": lambda x: x and "crs_next_sess=" in x}):
+            log.explain("Found session expansion button, skipping it as it has no content")
+            return None
+
         if img_tag is None:
             _unexpected_html_warning()
             log.warn_contd(f"Tried to figure out element type, but did not find an image for {url}")

PFERD/crawl/ilias/kit_ilias_web_crawler.py

@@ -234,19 +234,28 @@ instance's greatest bottleneck.
         async def gather_elements() -> None:
             elements.clear()
             async with cl:
-                soup = await self._get_page(url)
+                next_stage_url: Optional[str] = url
-
+                current_parent = None
-                if expected_id is not None:
-                    perma_link_element: Tag = soup.find(id="current_perma_link")
-                    if not perma_link_element or "crs_" not in perma_link_element.get("value"):
-                        raise CrawlError("Invalid course id? Didn't find anything looking like a course")
 
                 # Duplicated code, but the root page is special - we want to avoid fetching it twice!
-                log.explain_topic("Parsing root HTML page")
+                while next_stage_url:
-                log.explain(f"URL: {url}")
+                    soup = await self._get_page(next_stage_url)
-                page = IliasPage(soup, url, None)
-                elements.extend(page.get_child_elements())
 
+                    if current_parent is None and expected_id is not None:
+                        perma_link_element: Tag = soup.find(id="current_perma_link")
+                        if not perma_link_element or "crs_" not in perma_link_element.get("value"):
+                            raise CrawlError("Invalid course id? Didn't find anything looking like a course")
+
+                    log.explain_topic(f"Parsing HTML page for {fmt_path(cl.path)}")
+                    log.explain(f"URL: {next_stage_url}")
+                    page = IliasPage(soup, next_stage_url, current_parent)
+                    if next_element := page.get_next_stage_element():
+                        current_parent = next_element
+                        next_stage_url = next_element.url
+                    else:
+                        next_stage_url = None
+
+                elements.extend(page.get_child_elements())
                 if description_string := page.get_description():
                     description.append(description_string)