app/helpers/application_helper.rb

   1 module ApplicationHelper
   2
   3   ALL_PERMISSIONS = {read: true, write: true, manage: true}
   4
   5   def current_user
   6     controller.current_user
   7   end
   8
   9   def invalidate_permissions_cache
  10     Rails.cache.delete_matched(/^groups_for_user_/)
  11   end
  12
  13   def groups_i_can(verb)
  14     current_group_permissions.select { |uuid, mask| mask[verb] }.keys
  15   end
  16
  17   def current_group_permissions
  18     return {} unless current_user
  19     Rails.cache.fetch "groups_for_user_#{current_user.uuid}" do
  20       permissions_from = {}
  21       todo = {current_user.uuid => true}
  22       done = {}
  23       while !todo.empty?
  24         lookup_uuids = todo.keys
  25         lookup_uuids.each do |uuid| done[uuid] = true end
  26         todo = {}
  27         Link.where('tail_uuid in (?) and link_class = ? and head_kind = ?',
  28                    lookup_uuids,
  29                    'permission',
  30                    'orvos#group').each do |link|
  31           unless done.has_key? link.head_uuid
  32             todo[link.head_uuid] = true
  33           end
  34           link_permissions = {}
  35           case link.name
  36           when 'can_read'
  37             link_permissions = {read:true}
  38           when 'can_write'
  39             link_permissions = {read:true,write:true}
  40           when 'can_manage'
  41             link_permissions = ALL_PERMISSIONS
  42           end
  43           permissions_from[link.tail_uuid] ||= {}
  44           permissions_from[link.tail_uuid][link.head_uuid] ||= {}
  45           link_permissions.each do |k,v|
  46             permissions_from[link.tail_uuid][link.head_uuid][k] ||= v
  47           end
  48         end
  49       end
  50       search_permissions(current_user.uuid, permissions_from)
  51     end
  52   end
  53
  54   protected
  55
  56   def search_permissions(start, graph, merged={}, upstream_mask=nil, upstream_path={})
  57     nextpaths = graph[start]
  58     return merged if !nextpaths
  59     return merged if upstream_path.has_key? start
  60     upstream_path[start] = true
  61     upstream_mask ||= ALL_PERMISSIONS
  62     nextpaths.each do |head, mask|
  63       merged[head] ||= {}
  64       mask.each do |k,v|
  65         merged[head][k] ||= v if upstream_mask[k]
  66       end
  67       search_permissions(head, graph, merged, upstream_mask.select { |k,v| v && merged[head][k] }, upstream_path)
  68     end
  69     upstream_path.delete start
  70     merged
  71   end
  72
  73 end