Angular socket data caching/retrieval pattern check service for cached data else check local storage for data (optional) else make socket request for data (optional) then create listener for data from socket save obtained data to service save obtained data to localStorage (optional)

fetch.js

/**
* ## Fetch Data 
*
* @param {String} key Data source to request
* @param {Boolean} use_storage set/get from localStorage
* @param {Object} request JSON formatted request for server
*
* @return {Object} a $q.defer().promise for the data requested
*
*/
service.fetch =
  function(key, use_storage, request){
    var defer = $q.defer()
    var use_storage = use_storage || true
    var data = this[key] ? this[key] : false
    if (!data && use_storage) data = storageService.get(key)
    if (data){
      defer.resolve(data)
    } else {
      if (request){
        $rootScope.$watch
          ( socketService.open
          , function(newValue,oldValue){
              if (newValue == true){
                socketService.send(request)
              }
            }
          )
      }
      $rootScope.$on
      ( enumsService.socket + key
      , function(event, data){
          this[key] = data
          if (use_storage) storageService.set('key',data)
          defer.resolve(data)
        }
      )
      $timeout
        ( defer.resolve
          ( { status:enumsService.dataStatus.failure
            , message: 'server timeout'
            }
          )
          , 5000
        )
    }
    return defer.promise
  }