CODEWITHSUNDEEP
angularjs
Mawg
Mawg

Reputation: 40215

How can a service $watch another service's data?

I have two services which fetch two different kinds of data from my server. Each of those has two controllers which $scope.$watch that data for changes.

I wanted to get smart and detect loss/re-gain of internet connection, so I added an app.service('internetConnectionAvailableService'. When one of my data fetch services detects an HTTP result, it informs the "internetConnectionAvailableService" of success or failure.

I would like the other data fetch service to be aware of that.

I suppose that I could just lump both data fetch service into one & drop the internetConnectionAvailableService, but I would rather not (what if I end up with more data fetch services?).

So, I figure it's either broadcast / $on or use a $watch. Google seems to recommend using a $watch, but I can't seem to get it work in my data fetch service ....

app.service('GetServerDataService',function(){
   var serverData;
  return {
           getServerData: function()
            {
                return serverData;
            },

           $scope.$watch(internetConnectionAvailableService.isInternetConnectionAvailable,   
              function(){
         }
    }
 }

gives "Uncaught SyntaxError: Unexpected token . "

I am very new to Angular, so had a wild guess at using $rootscope.$watch instead, but that gives me the same message.

What am I doing wrong? How to I watch another service's data? Or should I use broadcast instead?

Update

I think I could have phrased this better and asked "How do communicate between two services?"

Upvotes: 3

Views: 250

Answers (1)

Nikola Yovchev
Nikola Yovchev

Reputation: 10276

EDIT:

It seems you want to communicate between services. You can indeed use $rootScope broadcast, which will trigger a broadcast storm along all your controllers and watches. A more object-oriented approach is to create a PubSub service which your services can inject and use. See also this question:

What's the correct way to communicate between controllers in AngularJS?

Upvotes: 2

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