agenticsim · January 3, 2016 13:39 · Jan 17, 2014 · Jan 17, 2014
diff --git a/pagination.rb b/pagination.rb
@@ -1,4 +1,4 @@
-class ApplicationController &lt; ActionController::Base
+class ApplicationController < ActionController::Base
   #...
   # this method expects a class to be passed with the attributes @@per_page,
   # @@:per_page_max defined

diff --git a/pagination.rb b/pagination.rb
@@ -0,0 +1,41 @@
+class ApplicationController &lt; ActionController::Base
+  #...
+  # this method expects a class to be passed with the attributes @@per_page,
+  # @@:per_page_max defined
+  def prepare_pagination(paginable_class)
+    # STEP 1:  Prepare values
+    # STEP 1a: Prepare page
+    # what the client wants or 1 per default
+    page = params[:page].nil??
+      1 : params[:page].to_i
+
+    # STEP 1b: Prepare per_page
+    # either use what the client asks for or take the models defaults
+    per_page = params[:per_page].nil??
+      paginable_class.per_page : params[:per_page].to_i
+
+    # STEP 2:  Sanity checks
+    # STEP 2a: Check page boundaries (page must at leaste be 1, but there are
+    # no max max restrictions, worst case: an empty set will be returned)
+    page = [page, 1].max
+
+    # STEP 2b: Assure proper boundaries for per_page:
+    # at least one per page but not more than the model allows us
+    per_page = [per_page, 1].max
+    per_page = [per_page, paginable_class.per_page_max].min
+
+    #return per_page, page
+    return per_page, page
+  end
+
+  # this method expects a WillPaginate::Collection to be given (aplying
+  # .paginate on models or scopes delivers these objects), examines it and
+  # delivers flincs cutom paginable http headers
+  def set_pagination_headers(p)
+    return unless p.is_a?(WillPaginate::Collection)
+    response.headers["X-Pagination-Total-Entries"] = p.total_entries.to_s
+    response.headers["X-Pagination-Per-Page"]      = p.per_page.to_s
+    response.headers["X-Pagination-Total-Pages"]   = p.total_pages.to_s
+    response.headers["X-Pagination-Current-Page"]  = p.current_page.to_s
+  end
+end