javascript - knockout JS : adding forms in foreach bindings

Question

我想添加一个“删除评论”按钮作为表单，该按钮会在使用 knockout 的 foreach 绑定(bind)生成的每个评论旁边触发 ajax 请求。 comments是一个可观察数组，每条评论都是一个 username 的对象, text , timestamp和commentID成员。加载以下内容而不使用 <form>元素工作正常:

<ul data-bind="foreach: comments">
    <li>
        <span data-bind="text: username"></span>
        <ul>
            <li data-bind="text: text"></li>
            <li data-bind="text: timestamp"></li>
            <form data-bind="if: sameUser" method="post" action="deleteComment.php">
                <input data-bind="attr: {id: commentID}, click: deleteComment" type="submit" value="Delete comment">
            </form>
        </ul>
    </li>
</ul>

但是，包括 <form>元素打破了 foreach 循环，仅加载一条注释。

我想使用if: sameUser数据绑定(bind)，以便删除按钮仅对发布评论的用户可见，并且 attr: {id: commentID} data-bind 在单击按钮时将要删除的正确评论 ID 发送到服务器，但现在我主要关心的是首先加载表单/按钮。

正确的方法是什么？

Answer 1

Not sure if you are writing delete function on comment level or its list level but if are binding the function use $parent to get out of foreach context.

以下是工作示例

function viewModel() {
  var self = this;
  
  self.comments = ko.observableArray([]);
  self.isDataLoaded = ko.observable(false);
  
  self.loadData = function(){
    setTimeout(function(){ 
      self.comments.push({username:"A", sameUser:true, commentID:1, text:"This is comment from A"});
      self.comments.push({username:"B", sameUser:true, commentID:2, text:"This is comment from B"});
      self.comments.push({username:"C", sameUser:false, commentID:3, text:"This is comment from C"});
      self.comments.push({username:"D", sameUser:true, commentID:4, text:"This is comment from D"});
      self.isDataLoaded(true);
    }, 2000);
  }
  self.deleteComment = function(data){
    self.comments.remove(data);
  }
}

var vm = new viewModel();
vm.loadData();
ko.applyBindings(vm);

<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.2/knockout-min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<ul data-bind="foreach: comments">
    <li>
        <span data-bind="text: username"></span>
        <ul>
            <li data-bind="text: text"></li>
            <!--<li data-bind="text: timestamp"></li> -->
            <form data-bind="if: sameUser" method="post">
                <input data-bind="attr: {id: commentID}, click: $parent.deleteComment" type="submit"        value="Delete comment">
            </form>
        </ul>
    </li>
</ul>