javascript - Gridstack 在删除时不更新

Question

这是我使用 Knockout 绑定(bind)的 Gridstack 布局示例。问题是我的 View 没有在应该更新的时候根据模型更新。

按下 Delete me 后，控制台输出显示 widgets 可观察数组得到正确更新，而 View 没有。原因似乎在这一行(未被调用):

ko.utils.domNodeDisposal.addDisposeCallback(item, function () { 
    self.grid.removeWidget(item); 
});

据我所知，foreach 绑定(bind)应该自动更新，为什么不呢？

var ViewModel = function() {
  var self = this;
  self.grid = null;
  self.widgets = ko.observableArray([{
    x: 0,
    y: 0,
    width: 1,
    height: 1
  }, {
    x: 0,
    y: 1,
    width: 1,
    height: 1
  }]);
  self.deleteWidget = function(item) {
    console.log("widgets before", self.widgets());
    self.widgets.remove(item);
    console.log("widgets after", self.widgets());
    return false;
  };
  self.afterAddWidget = function(items) {
    if (self.grid == null) {
      self.grid = $('.grid-stack').gridstack({
        auto: false
      }).data('gridstack');
    }
    var item = _.find(items, function(i) {
      return i.nodeType == 1
    });
    self.grid.addWidget(item);
    ko.utils.domNodeDisposal.addDisposeCallback(item, function() {
      self.grid.removeWidget(item);
    });
  };
};
ko.applyBindings(new ViewModel());

.grid-stack {
  background: lightgoldenrodyellow;
}
.grid-stack-item-content {
  color: #2c3e50;
  text-align: center;
  background-color: #18bc9c;
}

<link rel="stylesheet" href="https://raw.githubusercontent.com/troolee/gridstack.js/master/dist/gridstack.css" />
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js" type="text/javascript"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.11.0/jquery-ui.js" type="text/javascript"></script>
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js" type="text/javascript"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/lodash.js/3.5.0/lodash.min.js" type="text/javascript"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js" type="text/javascript"></script>
<script type="text/javascript" src="https://rawgit.com/troolee/gridstack.js/master/dist/gridstack.js"></script>

<div class="grid-stack" data-bind="foreach: {data: widgets, afterRender: afterAddWidget}">
  <div class="grid-stack-item" data-bind="attr: {'data-gs-x': $data.x, 'data-gs-y': $data.y, 'data-gs-width': $data.width, 'data-gs-height': $data.height, 'data-gs-auto-position': $data.auto_position}">
    <div class="grid-stack-item-content">
      <button data-bind="click: $root.deleteWidget">Delete me</button>
    </div>
  </div>
</div>

Answer 1

问题其实是</div>之间多了一个空格引起的关闭标签。 example对此发出警告。在我的例子中，它是由代码格式化程序自动插入的，因此没有引起注意。 HTML 模板中的行应为 </div></div><!-- <---- NO SPACE BETWEEN THESE CLOSING TAGS --> </div></div> 之间没有空格

var ViewModel = function() {
  var self = this;
  self.grid = null;
  self.widgets = ko.observableArray([{
    x: 0,
    y: 0,
    width: 1,
    height: 1
  }, {
    x: 0,
    y: 1,
    width: 1,
    height: 1
  }]);
  self.deleteWidget = function(item) {
    console.log("widgets before", self.widgets());
    self.widgets.remove(item);
    console.log("widgets after", self.widgets());
    return false;
  };
  self.afterAddWidget = function(items) {
    if (self.grid == null) {
      self.grid = $('.grid-stack').gridstack({
        auto: false
      }).data('gridstack');
    }
    var item = _.find(items, function(i) {
      return i.nodeType == 1
    });
    self.grid.addWidget(item);
    ko.utils.domNodeDisposal.addDisposeCallback(item, function() {
      self.grid.removeWidget(item);
    });
  };
};
ko.applyBindings(new ViewModel());

.grid-stack {
  background: lightgoldenrodyellow;
}
.grid-stack-item-content {
  color: #2c3e50;
  text-align: center;
  background-color: #18bc9c;
}

<link rel="stylesheet" href="https://raw.githubusercontent.com/troolee/gridstack.js/master/dist/gridstack.css" />
<script src="//ajax.googleapis.com/ajax/libs/jquery/1.11.1/jquery.min.js" type="text/javascript"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jqueryui/1.11.0/jquery-ui.js" type="text/javascript"></script>
<script src="//maxcdn.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js" type="text/javascript"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/lodash.js/3.5.0/lodash.min.js" type="text/javascript"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/knockout/3.2.0/knockout-min.js" type="text/javascript"></script>
<script type="text/javascript" src="https://rawgit.com/troolee/gridstack.js/master/dist/gridstack.js"></script>

<div class="grid-stack" data-bind="foreach: {data: widgets, afterRender: afterAddWidget}">
  <div class="grid-stack-item" data-bind="attr: {'data-gs-x': $data.x, 'data-gs-y': $data.y, 'data-gs-width': $data.width, 'data-gs-height': $data.height, 'data-gs-auto-position': $data.auto_position}">
    <div class="grid-stack-item-content">
      <button data-bind="click: $root.deleteWidget">Delete me</button>
    </div>
  </div></div><!-- <---- NO SPACE BETWEEN THESE CLOSING TAGS -->