AngularJS $ watch樹數組

Question

我有一個像這樣的樹數組：

Array
(
    [attributes] => Array
        (
            [attribute_group_id_6] => Array
                (
                    [id] => 6
                    [name] => Processor
                    [items] => Array
                        (
                            [0] => Array
                                (
                                    [product_id] => 40
                                    [attr_id] => 1
                                    [attr_text] => demo
                                    [attr_group_id] => 6
                                    [attr_group_order] => 1
                                    [attr_group_name] => Processor
                                )

                            [1] => Array
                                (
                                    [product_id] => 28
                                    [attr_id] => 2
                                    [attr_text] => 10
                                    [attr_group_id] => 6
                                    [attr_group_order] => 5
                                    [attr_group_name] => Processor
                                )

                            [2] => Array
                                (
                                    [product_id] => 28
                                    [attr_id] => 3
                                    [attr_text] => 777
                                    [attr_group_id] => 6
                                    [attr_group_order] => 3
                                    [attr_group_name] => Processor
                                )

                        )

                )

        )
    )

目標是購買items.[N].product_id .product_id更改。

該代碼可以看到更改，但是可以一次看到所有3個更改。

$scope.$watch('filterData.attributes.items', function(val, old) {
   console.log('watch');
}, true);

console:
watch
watch
watch

值通過文本字段更改：

問題是-如何僅觀看一項更改？ (attributes.attribute_group_id_6.items.[N].product_id)

Answer 1

您的回調會觸發整個items Array中的每次更改。 您真正需要的是每個項目的偵聽器，您可以在循環中創建該偵聽器-盡管JSHint可能不喜歡這樣。

for (var i = 0; i < $scope.filterData.attributes.items.length; i++) {
  $scope.$watch('filterData.attributes.items[' + i + ']', function(val, old) {
    console.log('watch');
  }, true);
}