Pagination

app/pagination/controllers/main_controller.rb

@@ -1,34 +1,18 @@
 module Pagination
   class MainController < Volt::ModelController
 
-    def middle_window(cpage, total)
-      side_size = ((window - 1) / 2).ceil
-
-      start_pos = cpage - side_size
-      end_pos = cpage + side_size
-
-      if start_pos <= 0
-        end_pos += (0 - start_pos) + 1
-        start_pos = 1
-      end
-
-      if end_pos > total
-        start_pos = [start_pos - (end_pos - total), 1].max
-        end_pos = total
-      end
-
-      end_pos = [end_pos, 1].max
-
-      return start_pos, end_pos
-    end
-
-    def page_numbers
+    def page_numbers(i=nil)
       total_pages.then do |total|
-
-        cpage = current_page()
-
-        start_pos, end_pos = middle_window(cpage, total)
-        middle_window = (start_pos..end_pos).to_a
+        if i == 0
+          start_pos, end_pos = middle_window(controller._pages[2] - 3, total)
+          middle_window = (start_pos..end_pos).to_a
+        elsif i == 1
+          start_pos, end_pos = middle_window(controller._pages[2] + window + 2, total)
+          middle_window = (start_pos..end_pos).to_a
+        else
+          start_pos, end_pos = middle_window(current_page, total)
+          middle_window = (start_pos..end_pos).to_a
+        end
 
         if outer_window == 0
           pages = middle_window
@@ -44,14 +28,23 @@ def page_numbers
           pages = start_window
           pages << nil unless start_outer_pos == (middle_window[0] - 1)
           pages += middle_window
-          pages << nil unless end_outer_pos == middle_window[-1] + 1
+          pages << 0 unless end_outer_pos == middle_window[-1] + 1
           pages += end_window
         end
+        controller._pages = pages
+      end
+    end
 
-        pages
+    def expand_pages x
+      page_numbers(x).then do |pages|
+        controller._pages = pages
       end
     end
 
+    def certain_page
+      controller._pages
+    end
+
     def window
       (attrs.window || 5).to_i
     end
@@ -60,6 +53,27 @@ def outer_window
       (attrs.outer_window || 1).to_i
     end
 
+    def middle_window cpage, total
+      side_size = ((window - 1) / 2).ceil
+
+      start_pos = cpage - side_size
+      end_pos = cpage + side_size
+
+      if start_pos <= 0
+        end_pos += (0 - start_pos) + 1
+        start_pos = 1
+      end
+
+      if end_pos > total
+        start_pos = [start_pos - (end_pos - total), 1].max
+        end_pos = total
+      end
+
+      end_pos = [end_pos, 1].max
+
+      [start_pos, end_pos]
+    end
+
     def per_page
       (attrs.per_page || 10).to_i
     end
@@ -83,37 +97,28 @@ def first_page
       current_page == 1
     end
 
-    def next_page_url
-      total_pages.then do |total_pages|
-        new_page = current_page + 1
-        if new_page > total_pages
-          next ''
-        end
-
-        url_for_page(new_page)
+    def goto_next_page
+      Promise.when(current_page, total_pages).then do |current_page, total_pages|
+        page = [(current_page + 1), total_pages].min
+        set_page(page)
       end
     end
 
-    def previous_page_url
-      new_page = current_page - 1
-      if new_page < 1
-        return ''
+    def goto_previous_page
+      current_page.then do |current_page|
+        page = [(current_page - 1), 1].max
+        set_page(page)
       end
-
-      return url_for_page(new_page)
     end
 
     def page_param_name
       attrs.page_param_name || :page
     end
 
-    def url_for_page(page_number)
-      url_with({page_param_name => page_number})
-    end
-
-    def set_page(page_number)
-      page_number = page_number.to_i
-      params.send(:"_#{page_param_name}=", page_number)
+    def set_page page_number
+      page_number.then do
+        params.send(:"_#{page_param_name}=", page_number.to_i)
+      end
     end
   end
 end

app/pagination/views/main/index.html

@@ -1,17 +1,19 @@
 <ul class="pagination">
   <li class="{{ if first_page }}disabled{{ end }}">
-    <a href="{{ previous_page_url }}">&laquo;</a>
+    <a e-click="goto_previous_page">&laquo;</a>
   </li>
-  {{ page_numbers.each do |page_number| }}
-    {{ if page_number.nil? }}
-      <li><a>...</a></li>
+  {{ certain_page.each do |page_number| }}
+    {{ if page_number.nil? }}<!-- first ... -->
+      <li><a e-click="expand_pages(0)">...</a></li>
+    {{ elsif page_number == 0 }}<!-- last ... -->
+      <li><a e-click="expand_pages(1)">...</a></li>
     {{ else }}
       <li class="{{ if current_page == page_number }}active{{ end }}">
-        <a href="{{ url_for_page(page_number) }}">{{ page_number }}</a>
+        <a e-click="set_page(page_number)">{{ page_number }}</a>
       </li>
     {{ end }}
   {{ end }}
   <li class="{{ if last_page }}disabled{{ end }}">
-    <a href="{{ next_page_url }}">&raquo;</a>
+    <a e-click="goto_next_page">&raquo;</a>
   </li>
 </ul>