angular/on-watch error

[tossp]

hi,guys
How do I fix this error？

Error Messages：

  131:7  error  The "$on" call should be assigned to a variable, in order to be destroyed during the $destroy event  angular/on-watch
  140:7  error  The "$on" call should be assigned to a variable, in order to be destroyed during the $destroy event  angular/on-watch
  145:7  error  The "$on" call should be assigned to a variable, in order to be destroyed during the $destroy event  angular/on-watch
  150:7  error  The "$on" call should be assigned to a variable, in order to be destroyed during the $destroy event  angular/on-watch

Corresponding Source：

      $rootScope.$on('$stateChangeStart', function (event, toState) {
        //$log.debug(1, '$stateChangeStart', event, toState, toParams, fromState, fromParams);

        handleHtmlId(toState);
        detachOnResize();
      });

      // initialized with 1 cause we came here with one $viewContentLoading request
      var viewContentLoading = 1;
      $rootScope.$on('$viewContentLoading', function () {
        //$log.debug(2, '$viewContentLoading', event, viewConfig);
        viewContentLoading++;
      });

      $rootScope.$on('$stateChangeSuccess', function () {
        //$log.debug(3, '$stateChangeSuccess', event, toState, toParams, fromState, fromParams);
        forceResizeTrigger = true;
      });

      $rootScope.$on('$viewContentLoaded', function () {
        //$log.debug(4, '$viewContentLoaded', event);
        viewContentLoading--;

        if (viewContentLoading === 0 && initialized) {
          debouncedRun();
        }
      });

[tilmanschweitzer]

Documentation: https://docs.angularjs.org/api/ng/type/$rootScope.Scope - Returns a deregistration function for this listener.

var deregisterationCallback = $rootScope.$on(....
$rootScope.$on('$destroy', deregistrationCallback)

http://stackoverflow.com/questions/25113884/should-angular-watch-be-removed-when-scope-destroyed

[tossp]

@tilmanpotthof Thank you very much!

[gitnik]

Does this really make sense? Shouldn't this lint ignore the $rootScope? Destroying the $rootScope implies the app being torn down, which makes unsubscribing kinda useless

[gitnik]

I would love to submit a PR if this behaviour is not wanted

[tilmanschweitzer]

@gitnik Good point. I think unsubscribing from the $rootScope does not make sense, at least with the $destroy event.

... or did I miss something? @remcohaszing @Gillespie59

[remcohaszing]

Seems legit.

[gitnik]

OK I will submit a PR then :-)

[gitnik]

Shouldn't this actually only lint on? Removing $watch is not needed, as the previously SO answer already explains

[laurent-le-graverend]

👍

[gitnik]

#264

[charneykaye]

Any reason not to do this?

$rootScope.$on('$destroy', $rootScope.$on(EVENTS.changeRegion, function() {
  vm.nowRegion = OpsService.getRegion();
}));