使用角度ng-click和ng-class更改类

Question

I have a series of menu items with submenus and they all have an angle-down icon that it's supposed to flip upwards using a class rotate180 . Problem is, I can't isolate the functionality so that it only happens in the menu I am opening and not all of them. ALSO, I need it to stay in the desired position according to the menu being open or closed. By either opening/closing the menu on clicking it or by canceling the icon flip once menu is opened. Hope that makes sense.

Here is my html

<div class="menu-item">
    <md-list id="playerTrigger" ng-click="menuIsOpen = 1; changeClass()" layout="row" layout-padding="" class="layout-row" layout-align="center center" flex>
        <span class="title flex" flex=""> Players</span>
        <span ng-class="class"></span>
    </md-list>
    <div class="sub-menu" ng-show="menuIsOpen===1" ng-animate="'animate'">
        <md-menu-item ng-repeat="item in vm.players">
            <md-button>
                <div layout="row" flex="">
                    <a ui-sref="{{item.linkto}}" class="">
                        <p flex="">{{item.title}}</p>
                    </a>
                </div>
            </md-button>
        </md-menu-item>
    </div>
</div>

And the controller

$scope.class = "ti-icon ti-mini right ti-angle-down";
$scope.changeClass = function() {
  if ($scope.class === "ti-icon ti-mini right ti-angle-down")
      $scope.class = "ti-icon ti-mini right ti-angle-down rotate180";
  else
      $scope.class = "ti-icon ti-mini right ti-angle-down";
};

Answer 1

Since you only need to toggle rotate180 class, I would keep the static classes in class attribute and the changing one in ng-class :

<span class="ti-icon ti-mini right ti-angle-down" ng-class="{'rotate180': rotate}"></span>

and in the controller:

$scope.rotate = false; //initial value 
$scope.changeClass = function() { 
     $scope.rotate = !$scope.rotate;
}