knockout binding a One-to-Many relationship on self (Recursion in knockout)

问题

So in my database I have a model that has a one to many relationship with itself. A good example of this is a comments system like on reddit.

I currently am doing something like this:

<div class="body" data-bind="foreach: { data: Comments}">
    <span data-bind="text: '(' + OrderQualifier + ') ' + Text"></span>
    <!-- ko foreach: { data: Children } -->
        <span data-bind="text: '(' + OrderQualifier + ') ' + Text"></span> 
    <!-- /ko -->
</div>

which obviously only supports one level of children. Is there a clean way to structure this when a Child (Children[i]) may or may not also have a Children array that needs to be looped over. In my example there could technically be infinite levels like this (it won't be).

I'm pretty sure I could come up with something hacky but I think there may be a better way. Thanks.

Edit:

Data that I would want to map:

{  
   "@odata.context":"http://localhost:3080/odata/$metadata#SectionApi(*)/$entity",
   "SectionID":4,
   "Text":"Text",
   "Html":null,
   "OrderQualifier":"1",
   "IsUserCreated":false,
   "Children":[  
      {  
         "@odata.context":"http://localhost:3080/odata/$metadata#SectionApi(*)/$entity",
         "SectionID":4,
         "Text":"Text",
         "Html":null,
         "OrderQualifier":"1",
         "IsUserCreated":false,
         "Children":[  
            {  
               "@odata.context":"http://localhost:3080/odata/$metadata#SectionApi(*)/$entity",
               "SectionID":4,
               "Text":"Text",
               "Html":null,
               "OrderQualifier":"1",
               "IsUserCreated":false,
               "Children":[  
                  {  
                     "@odata.context":"http://localhost:3080/odata/$metadata#SectionApi(*)/$entity",
                     "SectionID":4,
                     "Text":"Text",
                     "Html":null,
                     "OrderQualifier":"1",
                     "IsUserCreated":false,
                     "Children":[  

                     ]
                  }
               ]
            }
         ]
      }
   ]
}

As you can see this contains 3 levels of child comment but I need to be able to handle an unknown number of child comments.

回答1:

knockout template supports recursion. http://jsfiddle.net/m812qjeq/2/

<div class="body" data-bind="foreach: Comments">
    <div data-bind="template: { name: 'childTemplate', data: $data }"></div>
</div>

<script type="text/html" id="childTemplate">
    <span data-bind="text: '(' + OrderQualifier + ') ' + Text"></span>
    <!-- ko if: $data.Children -->
        <!-- ko foreach: Children -->
            <div data-bind="template: { name: 'childTemplate', data: $data }"></div>
        <!-- /ko -->
    <!-- /ko -->
</script>

回答2:

You can use template for this

<div class="body" data-bind="foreach: comments">
    <div data-bind="template: { name: 'childTemplate', data: $data }"></div>
</div>

<script type="text/html" id="childTemplate">
    <span data-bind="text:comment"></span>
    <!-- ko if: $data.childrenLength > 0 -->
        <!-- ko foreach: children -->
            <div data-bind="template: { name: 'childTemplate', data: $data }" style="padding-left:35px;"></div>
        <!-- /ko -->
    <!-- /ko -->
</script>

sample Viewmodel

var comments = [{
    id: 1,
    comment: 'How can i use knockoutjs?',
    childrenLength: 3,
    children: [{
        id: 2,
        comment: 'Please seach before asking',
        childrenLength: 0,
        children: []
    }, {
        id: 3,
        comment: 'Please read the documentation',
        childrenLength: 0,
        children: []
    }, {
        id: 4,
        comment: 'You can see the blog posts on this',
        childrenLength: 2,
        children: [{
            id: 5,
            comment: 'Please seach before asking',
            childrenLength: 0,
            children: []
        }, {
            id: 6,
            comment: 'Please seach before asking',
            childrenLength: 0,
            children: []
        }]
    }]
}, {
    id: 7,
    comment: 'You question is not sufficient to be asked here?',
    childrenLength: 3,
    children: [{
        id: 8,
        comment: 'Please seach before asking',
        childrenLength: 0,
        children: []
    }, {
        id: 9,
        comment: 'Please read the documentation',
        childrenLength: 0,
        children: []
    }, {
        id: 10,
        comment: 'You can see the blog posts on this',
        childrenLength: 0,
        children: []
    }]
}]

var vm = function(){
    var self = this
    self.comments = ko.observableArray(comments)
}

$('document').ready(function () {
    ko.applyBindings(new vm())
})

Fiddle Demo

来源：https://stackoverflow.com/questions/25217649/knockout-binding-a-one-to-many-relationship-on-self-recursion-in-knockout