我正在尝试使用 ko.mapping plugin 在树上进行递归模板化,但我无法渲染它,除非我定义单独 每个级别的模板。
在以下情况下,我想重用mvvmTreeViewGroupTemplate 对于 mvvmTreeViewSubGroups 也是如此,但这没有被渲染,是 这是一个错误还是未实现的功能?
<div id="treeViewArea">
<ul data-bind='template: {
name: "mvvmTreeViewGroupTemplate",
foreach: MvvmTreeItemGroups,
beforeRemove: function(elem) { $(elem).slideUp() },
afterAdd: function(elem) { $(elem).hide().slideDown() }
}'>
</ul>
</div>
<script type="text/x-jquery-tmpl" id="mvvmTreeViewGroupTemplate"> <li>
<span data-bind="text: Title" class="mvvmTreeItemStyle"/></br/> <ul data-bind='template: {
name: "mvvmTreeViewItemTemplate",
foreach: MvvmTreeItems,
beforeRemove: function(elem) { $ (elem).slideUp() },
afterAdd: function(elem) { $ (elem).hide().slideDown() }
}'>
<ul data-bind='template: {
name: "mvvmTreeViewSubGroupTemplate",
foreach: this.MvvmTreeItemSubGroups,
beforeRemove: function(elem) { $ (elem).slideUp() },
afterAdd: function(elem) { $ (elem).hide().slideDown() }
}'>
</ul>
</ul>
</li>
</script>
<script type="text/x-jquery-tmpl" id="mvvmTreeViewSubGroupTemplate"> <li>
<span data-bind="text: Title" class="mvvmTreeItemStyle"/></br/>
<ul data-bind='template: {
name: "mvvmTreeViewItemTemplate",
foreach: MvvmTreeItems,
beforeRemove: function(elem) { $ (elem).slideUp() },
afterAdd: function(elem) { $ (elem).hide().slideDown() }
}'>
</ul>
</li>
</script>
JSON 和脚本如下所示,
var data = {
MvvmTreeItemGroups: [
{
Id: 1, Title: 'Group 1',
MvvmTreeItemSubGroups: [{
Id: 1, Title: 'Group 11',
MvvmTreeItems: [{ Id: 'i111', Title: 'Item 111' },
{ Id: 'i112', Title: 'Item 112'}]
},
{
Id: 1, Title: 'Group 121',
MvvmTreeItems: [{ Id: 'i121', Title: 'Item
121' }, { Id: 'i122', Title: 'Item 122'}]
}],
MvvmTreeItems: [{ Id: 'i11', Title: 'Item 11' }, { Id:
'i12', Title: 'Item 12'}]
},
{
Id: 2, Title: 'Group 2',
MvvmTreeItemSubGroups: [{
Id: 1, Title: 'Group 211',
MvvmTreeItems: [{ Id: 'i211', Title: 'Item
211' }, { Id: 'i212', Title: 'Item 212'}]
},
{
Id: 1, Title: 'Group 121',
MvvmTreeItems: [{ Id: 'i121', Title: 'Item
121' }, { Id: 'i122', Title: 'Item 122'}]
}],
MvvmTreeItems: [{ Id: 'i21', Title: 'Item 21' },
{ Id: 'i22', Title: 'Item 22'}]
}]
};
var viewModel = ko.mapping.fromJS(data);
console.log(viewModel);
ko.applyBindings(viewModel, treeViewArea);
最佳答案
我在 this google thread 中得到了问题的答案。这不完全是一个“递归模板”问题,这是因为如果没有该名称的数组,模板不知道如何渲染。
有两种方法可以解决此问题:
检查 MvvmTreeItemGroups 数组是否 在渲染之前实际存在 像这样的模板,
{{if $data.MvvmTreeItemGroups }} <ul data-bind='template: { name: "mvvmTreeViewGroupTemplate", foreach: MvvmTreeItemGroups }'> </ul> {{/if}}
使用in关键字检查 MvvmTreeItemGroups确实存在
{if 'MvvmTreeItemGroups' in $data}} <ul data-bind='template: { name: "mvvmTreeViewGroupTemplate", foreach: MvvmTreeItemGroups }'> </ul> {{/if}}
完整的 fiddle 位于 http://jsfiddle.net/mikekidder/Xs7sy/
关于javascript - 使用 KnockoutJs 映射插件进行递归模板化,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/4750516/