Attempt to rescue and fallback to og:image url if extracted pixiv image doesn't resolve properly

slack-pixiv/commands/illust.rb

@@ -18,10 +18,10 @@ module SlackMathbot
         puts pixiv_url
 
         # Create iOS Illustration URL, regex pixiv_url to
-	# extract numbers only, such as /^[0-9]+$/
+        # extract numbers only, such as /^[0-9]+$/
         #ios_url = "pixiv://illusts/" + pixiv_url.split("illust_id=")[-1]
-       	ios_url = "pixiv://illusts/" + pixiv_url[/\d+/]
-	puts ios_url
+        ios_url = "pixiv://illusts/" + pixiv_url[/\d+/]
+        puts ios_url
 
         # Scrape profile link
         profile = agent.get(pixiv_url).at("div.userdata-row > h2.name > a").attributes['href'].to_s
@@ -37,6 +37,23 @@ module SlackMathbot
 
         # Scrape image
         image_url = agent.get(pixiv_url).images_with(:src => /600x600\/img-master/)[0].to_s.sub! '600x600','480x960'
+        begin
+          # Attempt to check on image
+          page = agent.head(image_url)
+
+          # Make sure page came back kosher
+          if page.code.to_i == 200
+            # Image url is fine
+            puts "Image is good to go!"
+          else
+            # Fallback on http error to be safe
+            image_url = "https://embed.pixiv.net/decorate.php?illust_id=" + pixiv_url[/\d+/]
+          end
+        rescue Mechanize::ResponseCodeError
+          # Fallback to og:image url
+          puts "Image failed to load"
+          image_url = "https://embed.pixiv.net/decorate.php?illust_id=" + pixiv_url[/\d+/]
+        end
         puts image_url
 
         client.web_client.chat_postMessage(