AngularJS $ scope。$监视ng-repeat中的元素

Question

我在带有Angular的.haml文件中有以下代码：

  %li.dropdown{"ng-repeat" => "region in regions"}
        %a{:href => "#"}
          %input{:type => "checkbox", "ng-model" => "PODLocation", "ng-true-value" => "filter", "ng-false-value" => "noFilter"}/
          %span.lbl {{region.toUpperCase()}}

AngularJS控制器内的以下内容：

   $scope.regions = [
        'am',
        'cn',
        'uk',
        'au',
        'ru'
    ];


   # Controls when the user selects options from dropdown menu
    $scope.$watch 'PODLocation', (value) ->
        console.log "In Search Location Watch"
        console.log "Inside Watch"
        switch value
          when "filter"
            $scope.search.location = region
          when "no-filter"
            $scope.search.location = ""

但似乎无论我如何调试它，$ scope。$ watch在每次单击复选框时都不会被调用（IE：每次点击时都不显示Console.log消息）。此外，似乎我可以同时选择多个复选框（由于angular将它们绑定到相同的PODLocation变量，因此不应该出现。）

有没有人有任何想法如何解决这个问题？