How to access object property from inside class function [duplicate]

Answer 1

Cache this so you can refer to it in the same context some place else:

function File(data){

  var self = this;

  self.data = data;

  self.update = function (callback){
    var set = function(ajaxData){
      self.data = ajaxData.PcbFile;
    }
    getPcbFile(data.id, function(ajaxData){
      set(ajaxData);
      callback();
    });
  };
}