http://stackoverflow.com/questions/42781703/ko-visible-not-working-with-template

by jlspake

HTML

<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.1.1/jquery.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/knockout/3.4.2/knockout-debug.js"></script>
<script id="FileElement" type="text/html">
    <ul style="border: 1px dashed blue">
        <li>
            <a href="#" data-bind="click: toggle" class="action-link"><br/>
                <span data-bind="text: ppp_name"></span>
            </a>

        		<ul data-bind="visible: show, template: { name: 'FileElement', foreach: ppp_children }" ></ul>

        </li>
    </ul>
</script>    

<div id="resources-panel" data-bind="template: { name: 'FileElement', foreach: $data.treeRoot }"></div>

JavaScript

var viewModel = {
    treeRoot: ko.observableArray()
};

var FileElement = function(ppp_name, ppp_type, ppp_children) {
   var self = this;

   self.ppp_children = ko.observableArray(ppp_children);
   self.ppp_name = ko.observable(ppp_name);
   self.ppp_type = ko.observable(ppp_type);

   self.show = ko.observable(false);

    self.toggle=function() {
        self.show(!self.show());
    }

  }


var tree = [
    new FileElement("IT Dept", "folder",[
        new FileElement("IT Overview.docx", "file",[]),
        new FileElement("IT Server1", "folder",[
            new FileElement("IT Server1 Configuration Part 1.docx", "file", []),
            new FileElement("IT Server1 Configuration Part 2.docx", "file", []),
            ]),
        new FileElement("IT Server2", "folder",[])
        ]), 
    new FileElement("HR Dept", "folder", [])   
];

viewModel.treeRoot(tree);

ko.applyBindings(viewModel,document.getElementById('resources-panel'));