EJS templates: How to generate an HTML tree structure in the most elegant and handy way

Question

I have this nested Array of Objects:

var tree = [
    {
        name: "item 1",
        link: "#link-1",
        children: [
            {
                name: "item 1.1",
                link: "#link-11",
                children: [
                    {
                        name: "item 1.1.1",
                        link: "#link-111",
                        children: []
                    }
                ]
            },
            {
                name: "item 1.2",
                link: "#link-12",
                children: []
            }
        ]
    },
    {
        name: "item 2",
        children: []
    }
];

I would like to generate an HTML ul li tree structure from this model.

The only solution I found is just below (via a recursive function). But I would like to avoid string concatenation, because in my real situation I have more markup to add on each rows of li (and this is really not handy).

<%
var markup = '';
function htmlTreeBuilder(items) {
    if (items.length) {
        markup += '<ul>';
    }
    for (var i = 0; i < items.length; i++) {
        markup += '<li>';
        markup += '<a href="' + items[i].link + '">' + items[i].name + '</a>';

        // Children
        htmlTreeBuilder(items[i].children);

        markup += '</li>';
    }
    if (items.length) {
        markup += '</ul>';
    }
}
htmlTreeBuilder(tree);
%>

<%- markup %>

Answer 1

I found a better approach, but it need a separate EJS file.

In my main.ejs:

<%- partial('treeView', {items: tree}) %>

In the treeView.ejs:

<% if (items.length) { %>
<ul>
<% } %>

    <% items.forEach(function(item){ %>
    <li>
        <a href="<%= item.link %>"><%= item.name %></a>
        <%- partial('treeView', {items: item.children}) %>
    </li>
    <% }) %>

<% if (items.length) { %>
</ul>
<% } %>