Mustache templates: How to output a block only once for non-empty lists

Question

If my list is empty, I want to output this:

If my list i

Answer 1

If you don't want to or can't reformat your data or templating engine, you can also just check items.length before rendering the <ul> tags. Some people frown upon this, but it's definitely an alternative to Max's answer.

{{#items.length}}
    <ul>
        {{items}}
            <li>{{name}}</li>
        {{/items}}
    </ul>
{{/items.length}}

Answer 2

You could use non-false values of a section. name would have to be an object inside of items

data = { 'items' : { 'name' : ["Item 1", "Item 2", "etc"] } };

You template would look like:

<div id="some-id">
    {{#items}}
    <ul>
        {{#name}}
        <li>{{.}}</li>
        {{/name}}
    </ul>
    {{/items}}
</div>

Here's an example on jsFiddle showing the rendering of an items object with names and without -- http://jsfiddle.net/maxbeatty/fpQwk/

Answer 3

The other two answers do not work for the Ruby implementation of Mustache. My solution was to send an additional parameter as part of the template context; e.g.

template = <<EOF
{{#has_items}}
<ul>
    {{#items}}
        <li>{{.}}</li>
    {{/items}}
</ul>
{{/has_items}}
EOF
items = ['one', 'two', 'three']
context = { items: items, has_items: items.any? }
Mustache.render(template, context)