Added session management for calendar month/year

lib/redmine_qbo_calendar/patches/calendars_controller_patch.rb

@@ -14,6 +14,17 @@ module RedmineQboCalendar
 
       def show
         log "show"
+
+        # 1. Update or retrieve saved month/year from session before super runs
+        if params[:year].present? && params[:month].present?
+          session[:qbo_calendar_year]  = params[:year].to_i
+          session[:qbo_calendar_month] = params[:month].to_i
+        elsif session[:qbo_calendar_year].present? && session[:qbo_calendar_month].present?
+          params[:year]  ||= session[:qbo_calendar_year]
+          params[:month] ||= session[:qbo_calendar_month]
+        end
+
+        # 2. Call Redmine core CalendarsController#show
         super
 
         return unless @calendar