- next entry/exit reader after finishing an entry

src/library.cr

@@ -106,6 +106,11 @@ class Title
 		end
 		read_pages / total_pages
 	end
+	def next_entry(current_entry_obj)
+		idx = @entries.index current_entry_obj
+		return nil if idx.nil? || idx == @entries.size - 1
+		@entries[idx + 1]
+	end
 end
 
 class TitleInfo

src/server.cr

@@ -168,7 +168,7 @@ class Server
 				title = (@library.get_title env.params.url["title"]).not_nil!
 				entry = (title.get_entry env.params.url["entry"]).not_nil!
 				page = env.params.url["page"].to_i
-				raise "" if page > entry.pages
+				raise "" if page > entry.pages || page <= 0
 
 				# save progress
 				username = get_username env
@@ -183,6 +183,9 @@ class Server
 				next_url = next_page > entry.pages ? nil :
 					"/reader/#{title.title}/#{entry.title}/#{next_page}"
 				exit_url = "/book/#{title.title}"
+				next_entry = title.next_entry entry
+				next_entry_url = next_entry.nil? ? nil : \
+					"/reader/#{title.title}/#{next_entry.title}"
 
 				render "src/views/reader.ecr"
 			rescue

src/views/reader.ecr

@@ -20,6 +20,11 @@
           <a class="next-url" href="<%= next_url %>"></a>
           <%- end -%>
       </div>
+      <%- if next_entry_url -%>
+      <button id="next-btn" class="uk-align-center uk-button uk-button-primary" hidden onclick="redirect('<%= next_entry_url %>')">Next Entry</button>
+      <%- else -%>
+      <button id="next-btn" class="uk-align-center uk-button uk-button-primary" hidden onclick="redirect('<%= exit_url %>')">Exit Reader</button>
+      <%- end -%>
     </div>
 
     <div id="hidden" hidden></div>
@@ -43,7 +48,7 @@
           </div>
         </div>
         <div class="uk-modal-footer uk-text-right">
-          <button class="uk-button uk-button-danger" type="button" onclick="exit('<%= exit_url %>')">Exit Reader</button>
+          <button class="uk-button uk-button-danger" type="button" onclick="redirect('<%= exit_url %>')">Exit Reader</button>
         </div>
       </div>
     </div>