How to use if statements in underscore.js templates?

javascript templates backbone.js underscore.js

This should do the trick:

<% if (typeof(date) !== "undefined") { %>    <span class="date"><%= date %></span><% } %>

Remember that in underscore.js templates if and for are just standard javascript syntax wrapped in <% %> tags.

javascript templates backbone.js underscore.js

If you prefer shorter if else statement, you can use this shorthand:

<%= typeof(id)!== 'undefined' ?  id : '' %>

It means display the id if is valid and blank if it wasn't.

javascript templates backbone.js underscore.js

Depending on the situation and or your style, you might also wanna use print inside your <% %> tags, as it allows for direct output. Like:

<% if (typeof(id) != "undefined") {     print(id);}else {    print('new Model');} %>

And for the original snippet with some concatenation:

<% if (typeof(date) != "undefined") {    print('<span class="date">' + date + '</span>');} %>

CodeHunter