--- ValBot/Python/check_interwiki_links.py	2022/02/21 23:59:20	1169
+++ ValBot/Python/check_interwiki_links.py	2023/04/28 00:54:21	1180
@@ -1,9 +1,19 @@
+# Check Interwiki Links
+# by iritscen@yahoo.com
+# Looks at each link on a page (or in all the pages in a category) which uses a registered
+# interwiki prefix and loads the linked page, verifying that it exists and that any section
+# link, if present, is valid as well. The output will use the word "ERROR" when it cannot
+# validate the interwiki link.
+# Recommended viewing width:
+# |---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---- ---|
+
 import os
 
 from urllib.parse import urljoin
 
 import pywikibot
 import re
+import requests # for listing members with dir()
 
 from pywikibot.bot import QuitKeyboardInterrupt
 from pywikibot import pagegenerators
@@ -17,119 +27,174 @@ interwiki_prefixes = ('acronym', 'cache'
 
 interwiki_urls = ('http://www.acronymfinder.com/~/search/af.aspx?string=exact&Acronym=', 'http://www.google.com/search?q=cache:', 'https://commons.wikimedia.org/wiki/', 'http://www.dict.org/bin/Dict?Database=*&Form=Dict1&Strategy=*&Query=', 'http://www.google.com/search?q=', 'https://meta.wikimedia.org/wiki/', 'https://www.mediawiki.org/wiki/', 'https://en.wikibooks.org/wiki/', 'https://www.wikidata.org/wiki/', 'https://foundation.wikimedia.org/wiki/', 'https://en.wikinews.org/wiki/', 'https://en.wikipedia.org/wiki/', 'https://en.wikiquote.org/wiki/', 'https://wikisource.org/wiki/', 'https://species.wikimedia.org/wiki/', 'https://en.wikiversity.org/wiki/', 'https://en.wikivoyage.org/wiki/', 'https://en.wiktionary.org/wiki/', 'https://en.wiktionary.org/wiki/', 'https://en.wikipedia.org/wiki/')
 
+# Initialize globals
+debug = 0
 pages_checked = 0
 iw_found = 0
-problems_found = 0
+errors_issued = 0
 
 # Searches the given page text for interwiki links
-def scan_for_iw_links(page_text):
-    global pages_checked
-    global iw_found
-    global problems_found
-    pages_checked = pages_checked + 1
-    cur = 0
-
-    for prefix in interwiki_prefixes:
-        # Isolate strings that start with "[[prefix:" and end with "|" or "]"
-        iw_link = "\[\[" + prefix + ":[^|\]]*(\||\])"
-        for match in re.finditer(iw_link, page_text):
-            # Extract just the page title from this regex match
-            s = match.start() + 2 + len(prefix) + 1
-            e = match.end() - 1
-
-            # Sometimes we used a space char. instead of a '_', so fix that before querying
-            page_title = page_text[s:e].replace(' ', '_')
-
-            # Construct full URL for the particular wiki
-            iw_url = interwiki_urls[cur] + page_title
-            pywikibot.output('Found {0} link {1}.'.format(prefix, page_title))
-            iw_found = iw_found + 1
-
-            # Adjust URL if this is a foreign-language WP link
-            if re.match("^[a-zA-Z]{2}:", page_title):
-                lang_code = page_title[0:2] + "."
-                # "wp:" is the Wikipedia: namespace, not a language
-                if lang_code != "wp." and lang_code != "WP.":
-                    iw_url = iw_url.replace('en.', lang_code)
-                    iw_url = iw_url.replace(page_title[0:3], '')
-
-            # Test the URL
-            #pywikibot.output('Testing URL {}...'.format(iw_url))
-            response = fetch(iw_url)
-
-            # Redirects are followed automatically by fetch() and treated as "200"s, so the
-            # way we tell that a redirect occurred is by checking the history
-            if response.history != []:
-                pywikibot.output('WARNING: Redirected from {}.'.format(response.history))
-                problems_found = problems_found + 1
-            elif response.status_code != 200:
-                #pywikibot.output('WARNING: Got response code {}.'.format(response.status_code)) # commented out because fetch() already prints such a msg
-                problems_found = problems_found + 1
-            elif '#' in page_title:
-                # Isolate section link
-                pywikibot.output('Detected section link on page {0}.'.format(page_title))
-                page_name, anchor_name = page_title.split('#')
-                
-                # Convert dot-notation hex entities to proper characters
-                anchor_name = anchor_name.replace('.22', '"')
-                anchor_name = anchor_name.replace('.27', '\'')
-                anchor_name = anchor_name.replace('.28', '(')
-                anchor_name = anchor_name.replace('.29', ')')
-                
-                # Read linked page to see if it really has this anchor link
-                soup = BeautifulSoup(response.text, 'html.parser')
-                found_section = False
-                for tag in soup.findAll('a'):
-                    link = tag.get('href', None)
-                    if not link:
-                        #pywikibot.output('It is not a link.')
-                        continue
-                    #pywikibot.output('Got link {0}.'.format(link))
-                    if not link.startswith('#'):
-                        continue
-                        
-                    if link == '#' + anchor_name:
-                        pywikibot.output('Found section link!')
-                        found_section = True
-                        break
-                if found_section == False:
-                    pywikibot.output('Could not find section {0} on page {1}.'.format(anchor_name, page_name))
-                    problems_found = problems_found + 1
-        cur = cur + 1
+def scan_for_interwiki_links(page_text, page_name):
+   global debug
+   global pages_checked
+   global iw_found
+   global errors_issued
+   pages_checked = pages_checked + 1
+   cur = 0
+   name_printed = 0
+
+   for prefix in interwiki_prefixes:
+      # Isolate strings that start with "[[prefix:" and end with "|" or "]"
+      iw_link = "\[\[" + prefix + ":[^|\]]*(\||\])"
+      for match in re.finditer(iw_link, page_text):
+         # Extract just the page title from this regex match
+         s = match.start() + 2 + len(prefix) + 1
+         e = match.end() - 1
+
+         # Sometimes we used a space char. instead of a '_', so fix that before querying
+         page_title = page_text[s:e].replace(' ', '_')
+
+         # Use only spaces for title when printing it
+         page_title_human = page_title.replace('_', ' ')
+         if debug: pywikibot.stdout('   Validating {0} link "{1}"'.format(prefix, page_title_human))
+         iw_found = iw_found + 1
+
+         # Construct full URL for the particular wiki
+         iw_url = interwiki_urls[cur] + page_title
+
+         # Adjust URL if this is a foreign-language WP link
+         if re.match("^[a-zA-Z]{2}:", page_title):
+            lang_code = page_title[0:2] + "."
+            # "wp:" is the Wikipedia: namespace, not a language
+            if lang_code != "wp." and lang_code != "WP.":
+               iw_url = iw_url.replace('en.', lang_code)
+               iw_url = iw_url.replace(page_title[0:3], '')
+
+         # Test the URL
+         response = fetch(iw_url)
+
+         # One way we tell that a redirect occurred is by checking the history
+         if response.history != []:
+            if not name_printed and not debug:
+               pywikibot.stdout('From page "{}":'.format(page_name))
+               name_printed = 1
+            if page_title.startswith('WP:') and page_title == page_title.upper():
+               pywikibot.stdout('   ERROR: Got redirection code ({0}) for {1} link "{2}", but this appears to be a deliberate use of a Wikipedia shortcut. You should check the link manually.'.format(response.history[0], prefix, page_title))
+            else:
+               pywikibot.stdout('   ERROR: Got redirection code ({0}) for {1} link "{2}". You should check the link manually.'.format(response.history[0], prefix, page_title))
+            errors_issued = errors_issued + 1
+         elif response.status_code != 200:
+            if not name_printed and not debug:
+               pywikibot.stdout('From page "{}":'.format(page_name))
+               name_printed = 1
+            pywikibot.stdout('   ERROR: Got response code {0} for {1} link "{2}". The page may not exist.'.format(response.status_code, prefix, page_title))
+            errors_issued = errors_issued + 1
+         # The usual way that a redirect occurs is that MediaWiki redirects us sneakily
+         # using JavaScript, while returning code OK 200 as if the link was correct; we
+         # must detect this from the page source
+         elif 'Redirected from <a' in response.text:
+            if not name_printed and not debug:
+               pywikibot.stdout('From page "{}":'.format(page_name))
+               name_printed = 1
+            # Extract link from this source which contains name of redirected-to page:
+            # <link rel="canonical" href="https://en.wikipedia.org/wiki/Page_name"/>
+            canonical_name = response.text.split('<link rel="canonical" href="')[-1]
+            prefix_length = len(interwiki_urls[cur])
+            canonical_name = canonical_name[prefix_length:]
+            tag_end = canonical_name.find('"/>')
+            if tag_end == -1:
+               pywikibot.stdout('   ERROR: The {0} link "{1}" is a redirect page, but this script could not isolate the target page name.', format(prefix, page_title))
+            else:
+               canonical_name = canonical_name[:tag_end]
+               if len(canonical_name) > 100:
+                 # Certain things can cause the trim to fail; here we avoid slamming
+                 # the output with massive page source from a failed trim
+                 pywikibot.stdout('   ERROR: The {0} link "{1}" is a redirect to "{2}…" (string trimmed to 100 chars).'.format(prefix, page_title, canonical_name[:100]))
+               else:
+                 canonical_name = canonical_name.replace('_', ' ')
+                 pywikibot.stdout('   ERROR: The {0} link "{1}" is a redirect to "{2}".'.format(prefix, page_title, canonical_name))
+            errors_issued = errors_issued + 1
+         elif '#' in page_title:
+            # Isolate section link
+            target_page_name, anchor_name = page_title.split('#')
+            
+            # Convert dot-notation hex entities to proper characters
+            anchor_name = anchor_name.replace('.22', '"')
+            anchor_name = anchor_name.replace('.27', '\'')
+            anchor_name = anchor_name.replace('.28', '(')
+            anchor_name = anchor_name.replace('.29', ')')
+            
+            # Read linked page to see if it really has this anchor link
+            soup = BeautifulSoup(response.text, 'html.parser')
+            found_section = False
+            for span_tag in soup.findAll('span'):
+               span_name = span_tag.get('id', None)
+               if span_name == anchor_name:
+                  found_section = True
+                  break
+            if found_section == False:
+               if not name_printed and not debug:
+                  pywikibot.stdout('From page "{}":'.format(page_name))
+                  name_printed = 1
+               target_page_name_human = target_page_name.replace('_', ' ')
+               pywikibot.stdout('   ERROR: Could not find section "{0}" on {1} page "{2}".'.format(anchor_name, prefix, target_page_name_human))
+               errors_issued = errors_issued + 1
+      cur = cur + 1
 
 def main(*args):
-    cat_name = ''
-    page_name = ''
-
-    local_args = pywikibot.handle_args(args)
-    genFactory = pagegenerators.GeneratorFactory()
+   global debug
+   search_cat = ''
+   search_page = ''
+
+   local_args = pywikibot.handle_args(args)
+   genFactory = pagegenerators.GeneratorFactory()
+
+   for arg in local_args:
+      if arg.startswith('-cat:'):
+         search_cat = arg[5:]
+      elif arg.startswith('-page:'):
+         search_page = arg[6:]
+      elif arg == '-dbg':
+         debug = 1
+      else:
+         pywikibot.stdout('Unknown argument "{}".'.format(arg))
+         return
+
+   site = pywikibot.Site()
+
+   #pywikibot.stdout('The members of the requests.models.Response class are:')
+   #pywikibot.stdout(format(dir(requests.models.Response)))
+
+   if search_cat != '':
+      cat_obj = pywikibot.Category(site, search_cat)
+      generator = pagegenerators.CategorizedPageGenerator(cat_obj, recurse=True)
+      for page in pagegenerators.PreloadingGenerator(generator, 100):
+         if debug: pywikibot.stdout('Checking page "{}"'.format(page.title()))
+         scan_for_interwiki_links(page.text, page.title())
+   elif search_page != '':
+      page = pywikibot.Page(site, search_page)
+      if debug: pywikibot.stdout('Checking page "{}"'.format(page.title()))
+      scan_for_interwiki_links(page.text, page.title())
+
+   global pages_checked
+   global iw_found
+   global errors_issued
+
+   page_str = "pages"
+   if pages_checked == 1:
+      page_str = "page"
+
+   link_str = "links"
+   if iw_found == 1:
+      link_str = "link"
+
+   pywikibot.stdout('Checked {0} {1} and found {2} interwiki {3}.'.format(pages_checked, page_str, iw_found, link_str))
+
+   error_str = "errors were"
+   if errors_issued == 1:
+      error_str = "error was"
 
-    for arg in local_args:
-        if arg.startswith('-cat:'):
-            cat_name = arg[5:]
-        elif arg.startswith('-page:'):
-            page_name = arg[6:]
-
-    site = pywikibot.Site()
-
-    # This line of code enumerates the methods in the 'page' class
-    #pywikibot.stdout(format(dir(page)))
-
-    if cat_name != '':
-        cat_obj = pywikibot.Category(site, cat_name)
-        generator = pagegenerators.CategorizedPageGenerator(cat_obj, recurse=True)
-        for page in pagegenerators.PreloadingGenerator(generator, 100):
-            pywikibot.stdout('Checking page {0}'.format(page.title()))
-            scan_for_iw_links(page.text)
-    elif page_name != '':
-        page = pywikibot.Page(site, page_name)
-        pywikibot.stdout('Checking page {0}'.format(page.title()))
-        scan_for_iw_links(page.text)
-
-    global pages_checked
-    global iw_found
-    global problems_found
-    pywikibot.stdout('Checked {0} page(s) and found {1} interwiki link(s) with {2} problem(s).'.format(pages_checked, iw_found, problems_found))
+   pywikibot.stdout('{0} {1} encountered in validating these links.'.format(errors_issued, error_str))
 
 if __name__ == '__main__':
-    main()
+   main()