Embedded JavaScript templates


Embedded JavaScript templates

$ npm install ejs
  • Control flow with <% %>
  • Escaped output with <%= %>
  • Unescaped raw output with <%- %>
  • Trim-mode ('newline slurping') with -%> ending tag
  • Custom delimiters (e.g., use '' instead of '<% %>')
  • Includes
  • Client-side support
  • Static caching of intermediate JavaScript
  • Static caching of templates
  • Complies with the Express view system
<% if (user) { %>
  <h2><%= user.name %></h2>
<% } %>
var template = ejs.compile(str, options);
// => Rendered HTML string 
ejs.render(str, data, options);
// => Rendered HTML string 

You can also use the shortcut ejs.render(dataAndOptions); where you pass everything in a single object. In that case, you'll end up with local variables for all the passed options.

  • cache Compiled functions are cached, requires filename
  • filename Used by cache to key caches, and for includes
  • context Function execution context
  • compileDebug When false no debug instrumentation is compiled
  • client Returns standalone compiled function
  • delimiter Character to use with angle brackets for open/close
  • debug Output generated function body
  • _with Whether or not to use with() {} constructs. If false then the locals will be stored in the locals object.
  • rmWhitespace Remove all safe-to-remove whitespace, including leading and trailing whitespace. It also enables a safer version of -%> line slurping for all scriptlet tags (it does not strip new lines of tags in the middle of a line).
  • <% 'Scriptlet' tag, for control-flow, no output
  • <%= Outputs the value into the template (HTML escaped)
  • <%- Outputs the unescaped value into the template
  • <%# Comment tag, no execution, no output
  • <%% Outputs a literal '<%'
  • %> Plain ending tag
  • -%> Trim-mode ('newline slurp') tag, trims following newline

Includes either have to be an absolute path, or, if not, are assumed as relative to the template with the include call. (This requires the filename option.) For example if you are including ./views/user/show.ejs from ./views/users.ejs you would use <%- include('user/show') %>.

You'll likely want to use the raw output tag (<%-) with your include to avoid double-escaping the HTML output.

  <% users.forEach(function(user){ %>
    <%- include('user/show', {user: user}) %>
  <% }); %>

Includes are inserted at runtime, so you can use variables for the path in the include call (for example <%- include(somePath) %>). Variables in your top-level data object are available to all your includes, but local variables need to be passed down.

NOTE: Include preprocessor directives (<% include user/show %>) are still supported.

Custom delimiters can be applied on a per-template basis, or globally:

var ejs = require('ejs'),
    users = ['geddy', 'neil', 'alex'];
// Just one template 
ejs.render('<?= users.join(" | "); ?>', {users: users}, {delimiter: '?'});
// => 'geddy | neil | alex' 
// Or globally 
ejs.delimiter = '$';
ejs.render('<$= users.join(" | "); $>', {users: users});
// => 'geddy | neil | alex' 

EJS ships with a basic in-process cache for caching the intermediate JavaScript functions used to render templates. It's easy to plug in LRU caching using Node's lru-cache library:

var ejs = require('ejs')
  , LRU = require('lru-cache');
ejs.cache = LRU(100); // LRU cache with 100-item limit 

If you want to clear the EJS cache, call ejs.clearCache. If you're using the LRU cache and need a different limit, simple reset ejs.cache to a new instance of the LRU.

EJS does not specifically support blocks, but layouts can be implemented by including headers and footers, like so:

<%- include('header') -%>
  My page
<%- include('footer') -%>

Go to the Latest Release, download ./ejs.js or ./ejs.min.js.

Include one of these on your page, and ejs.render(str).

There are a number of implementations of EJS:

  • TJ's implementation, the v1 of this library: https://github.com/tj/ejs
  • Jupiter Consulting's EJS: http://www.embeddedjs.com/
  • EJS Embedded JavaScript Framework on Google Code: https://code.google.com/p/embeddedjavascript/
  • Sam Stephenson's Ruby implementation: https://rubygems.org/gems/ejs
  • Erubis, an ERB implementation which also runs JavaScript: http://www.kuwata-lab.com/erubis/users-guide.04.html#lang-javascript

Licensed under the Apache License, Version 2.0 (http://www.apache.org/licenses/LICENSE-2.0)

EJS Embedded JavaScript templates copyright 2112 mde@fleegix.org.