Call a function of Controller "One" inside Controller "Two" - IONIC1

app.controller('One', ['$scope', '$rootScope'
    function($scope) {
        $rootScope.$on("CallParentMethod", function(){
           $scope.parentmethod();
        });

        $scope.parentmethod = function() {
            // task
        }
    }
]);
app.controller('two', ['$scope', '$rootScope'
    function($scope) {
        $scope.childmethod = function() {
            $rootScope.$emit("CallParentMethod", {});
        }
    }
]);




While $rootScope.$emit is called, you can send any data as second parameter.

Solution for IONIC2+  will be up soon.