使用angular指令添加CSS元素

Im using angular and ng-repeat to populate a list of studies. This list is dynamic so you can toggle into child elements of each element. So basically I have a accordion style toggle list that can go three levels deep on each list item. I have a jQuery issue that I think should be solved with some angular directive or something. Basically I have an arrow (glyphicon) that should switch to up or down depending on if your looking at a child or a parent element in this list. I have this working with pure jQuery just adding and removing a css class from each list item. However, it only works on the first item in the list because ng-repeat creates multiple id’s but jQuery will only work on the first element with that id tag.Im using angular and ng-repeat to populate a li