Reusing templates with partials in Handlebars
Handlebars partials are templates which can be invoked from other templates with a certain context.
One example use of a partial template is a user login box. Such a box would display the username, the number of unread notifications, and a logout link if the user is logged in; otherwise it would display regular login options which are available while using Facebook and Twitter.
Partial templates can be used instead of helpers when there are no parameters to be passed to the helper or when no complex logic is necessary. They're particularly useful when the amount of dynamically generated content is small and the amount of HTML is large. This is because inside partial templates, HTML can be written directly without the need to convert it to strings.
In this recipe, we're going to use partial templates to render a threaded conversation model. This example also demonstrates that partial templates can be re-used recursively from within themselves.