javascript - Check network and handle empty error object -

i using parse.com backend ionic framework app means have monitor network activity. can handle online / offline using guide. however, need more 'app wide' solution checks on each call. i'm getting errors when there no network response server null causing following error:

error: null not object (evaluating 'response.error') 

my question 2 fold:

1. is possible create network factory / service can inject parsefactory check , notify user network insufficient.

2. handle null response object in code:

   parsefactory.provider('programme/').get($stateparams.loadprogramme).success (function(data){  // success...  }).error(function(response){  $rootscope.$emit('errorevent',     {"message" : "unable load programme. please check  connection", "errorobject": response.error}      ); }); 

my factory parse calls below:

.factory('parsefactory',['$http','parse_credentials',function($http,parse_credentials){ var baseurl = 'https://api.parse.com/1/classes/';     return {         provider:function(type, queryparam, queryvalue) {             console.log(queryvalue);             wherequery = {}             wherequery[queryparam] = queryvalue;              var masterquery = {'userid': masterkey};             return {                 getall:function(){                     return $http.get(geturl(type),getparams(wherequery));                 },                 getmasters:function(){                     return $http.get(geturl(type),getparams(masterquery));                 },                 get:function(id){                     return $http.get(geturl(type)+id,getparams());                 },                 create:function(data){                     return $http.post(geturl(type),data,getparams());                 },                 edit:function(id,data){                     return $http.put(geturl(type)+id,data,getparams());                 },                 delete:function(id){                     return $http.delete(geturl(type)+id,getparams());                 }             }             function geturl(type) {                 return baseurl+type;             }              function getparams(user) {                 return {                         timeout : 5000,                         headers:{                             'x-parse-application-id': parse_credentials.app_id,                             'x-parse-rest-api-key':parse_credentials.rest_api_key,                             'x-parse-session-token': parse.user.current()._sessiontoken,                             'content-type':'application/json'                         },                         params: {                          where: user,                          // limit: 2,                          // count: 1                          // include: "something"                     }                       }                 }         }     } }]) 

use $http interceptor. requests using $http passed through interceptors, using interceptors can apply global handling successful or unsuccessful requests , responses.

for example, interceptor cancels request if network connection not available , emits event when empty response received:

app.factory('networkactivityinterceptor', function($rootscope, $q, networkmonitorservice) {   return {     'request': function(config) {       var canceller = $q.defer();       config.timeout = canceller.promise;        if (!networkmonitorservice.hasnetworkconnection()) {         // cancels request if there no network connection         canceller.resolve();       }        // otherwise, let request go through normal       return config;     },      'response': function(response) {       // handle null/empty response       if (!response.data) {         $rootscope.$emit('errorevent', {           message: 'unable load...',           errorobject: response.error         });       }        return response;     },      'responseerror': function(response) {       // response handling above done in responseerror       // handler hit when error http code returned. (example: 404, 500)       // depends on server configured return.        // note in responseerror handler must return rejected promise       // (i.e. return $q.reject(response);)     }   }; }); 

substitute networkmonitorservice.hasnetworkconnection() app's network activity logic.