AngularJS Directive: Checkbox Set

checkbox.coffee

app.directive 'checkbox', (Page) ->
  # Page should be refreshed upon entering the page, within page controller
  restrict: 'E'
  scope:
    hook: '@'
    hookedTo: '@'
    checkedStoredIn: '='
  templateUrl: 'checkbox.html'
  link: (scope, element, attr) ->
    hookName = scope.hook || scope.hookedTo
    Page.checkboxGroups ?= {}
    hookObj = Page.checkboxGroups[hookName] ?= {}
    childrenArr = Page.checkboxGroups[hookName].childrenArr ?= []
    
    # store parent obj if there is one
    if scope.hook then hookObj.parentObj = scope.checkedStoredIn
    # else add children to the list
    else childrenArr.push(scope.checkedStoredIn)
      
    scope.toggleCheck = ->
      scope.checkedStoredIn.checked = !scope.checkedStoredIn.checked
      
      if scope.hook
        if (childrenArr.every (e) -> e.checked is true)
          childrenArr.forEach (e) -> e.checked = false
        else
          childrenArr.forEach (e) -> e.checked = true
      else
        # uncheck the parent checkbox if any of its children unchecked
        if hookObj.parentObj? && !(childrenArr.every (e) -> e.checked is true)
          hookObj.parentObj.checked = false
    
app.value 'Page', {}
app.controller 'pageX', (Page) -> Page = {}

checkbox.html

<div class="checkbox-outer" ng-click="toggleCheck()">
    <div class="checkbox-inner" ng-show="checkedStoredIn.checked"></div>
</div>

checkbox.less

checkbox{
    cursor: pointer;
    .checkbox-outer{
        width: 20px;
        height: 20px;
        border: 1px solid grey;
        background-color: white;
    }
    .checkbox-inner{
        width: 100%;
        height: 100%;
        background-color: black;
    }
}

index.html

<!-- Have one or zero parent checkbox -->
<checkbox hook="A" checked-stored-in="setA"></checkbox>
<!-- Have multiple children checkbox -->
<checkbox hooked-to="A" checked-stored-in="obj1"></checkbox>
<checkbox hooked-to="A" checked-stored-in="obj2"></checkbox>
<checkbox hooked-to="A" checked-stored-in="obj3"></checkbox>