对象更改时绑定不会更新

Question

I have an array that is, basically, a subset of another array:

$scope.theFew = $scope.theMany.filter(function(obj, index, array) {
   return obj.IsVerySpecial;
});

Elsewhere in my controller, I have some functions that act on theMany array, changing the IsVerySpecial property.

I'd expect $scope.theFew to update when objects within $scope.theMany have their properties change, but that isn't the case. What's going on?

Answer 1

A quick discovery on this, but it worked. To be fair, this was some older code ;)

The code should instead read:

$scope.theFew = function() {
  return $scope.theMany.filter(function(obj, index, array) {
     return obj.IsVerySpecial;
  });
}

Answer 2

I too had a similar issue. I have used the $watch to update scope variables. Not sure if this is the best way.

    controller: ['$scope', function($scope) {
        updateVisualData();

        $scope.$watch("data", function(newData) {
            console.log("new Data in paContent");
            console.log(newData);
            updateVisualData();
        }, true);

        function updateVisualData() {
            var contentData = $scope.data.components && $scope.data.components.filter(function(item) {
                return item.type === "Layout";
            });
            if (contentData && contentData.length > 0) {
                contentData = contentData[0];
                $scope.graphType = contentData.graph.type;
                $scope.graphData = contentData.graph.graphData;
                -----
            }
        }
    }]