template.js
A fast django-like templating engine for node.js.
template.js is a templating engine inspired by the django syntax. It has a few extensions and the templates are compiled to native javascript functions which make them really fast. For now it's synchronous, but once a template is read and compiled, it is cached in memory.
Example template code
<html>
<body>
<h1>Example</h1>
{% for name in names %}
<p>
{{forloop.counter}}
{# This is a comment #}
{{name}}{% if name == "Django" %} Reinhardt{% end %}
</p>
{% end %}
</body>
</html>
Example node code
var template = require('template.js');
var tmpl = template.fromFile("/path/to/template.html");
console.log(tmpl.render({names: ["Duke", "Django", "Louis"]}));
How it works
template.js reads template files and translates them into javascript functions using the Function constructor. When we later render a template we call the evaled function passing a context object as an argument. This makes the rendering very fast. The template tags are defined as strings of Javascript code - which is a bit ugly, but there are helpers that will make writing tags easier for you.
The slots system will allow you to define your own HTML snippets that will be rendered with a special context.
The API
You have 2 methods for creating a template object:
var template = require('node-slots');
template.fromFile("path/to/template/file.html");
template.fromString("Template string here");
Both of them will give you a template object on which you call the render method passing it a map of context values.
var tmpl = template.fromFile("path/to/template/file.html");
var renderdHtml = tmpl.render({});
Template syntax
You should be familiar with the Django template syntax. Here I'll just sum up the diferences:
- There are no filters implemented yet
- Tags like {% for %} and {% if %} are closed with a simple {% end %} tag
- Not all tags are implemented
- Some extra tags are implemented
- Syntax for some tags is a bit different.
Here's a list of currently implemented tags:
Variable tags
Used to print a variable to the template. If the variable is not in the context we don't get an error, rather an empty string. You can use dot notation to access object proerties or array memebers.
<p>First Name: {{users.0.first_name}}</p>
Variable Filters
Used to modify variables. Filters are added directly after variable names, separated by the pipe (|) character. You can chain multiple filters together, applying one after the other in succession.
{{ foo|reverse|join(' ')|title }}
default(default_value)
If the variable is undefined, null, or false, a default return value can be specified.
{{ foo|default('foo is not defined') }}
lower
Return the variable in all lowercase letters.
upper
Return the variable in all uppercase letters
capitalize
Capitalize the first character in the string.
title
Change the output to title case–the first letter of every word will uppercase, while all the rest will be lowercase.
join
If the value is an Array, you can join each value with a delimiter and return it as a string.
{{ authors|join(', ') }}
reverse
If the value is an Array, this filter will reverse all items in the array.
length
Return the length property of the value.
url_encode
Encode a URI component.
url_decode
Decode a URI component.
json_encode
Return a JSON string of the variable.
striptags
Strip all HTML/XML tags.
date
Convert a valid date into a format as specified. Mostly conforms to (php.net's date formatting)[http://php.net/date].
{{ post.created|date('F jS, Y') }}
Comment tags
Comment tags are simply ignored. Comments can't span multitple lines.
{# This is a comment #}
Logic tags
extends / block
Check django's template inheritance system for more info. Unlike django, the block tags are terminated with {% end %}, not with {% endblock %}
include
Includes a template in it's place. The template is rendered within the current context. Does not requre closing with {% end %}.
{% include template_path %}
{% include "path/to/template.js" %}
for
You can iterate arrays and objects. Access the current iteration index through 'forloop.index' which is available inside the loop.
{% for x in y %}
<p>{% forloop.index %}</p>
{% end %}
if
Supports the following expressions. No else tag yet.
{% if x %}{% end %}
{% if !x %}{% end %}
{% if x operator y %}
Operators: ==, !=, <, <=, >, >=, ===, !==, in
The 'in' operator checks for presence in arrays too.
{% end %}
{% if x == 'five' %}
The operands can be also be string or number literals
{% end %}
slot
Use slots where you want highly customized content that depends heavily on dynamic data. They work in pair with widget functions that you can write yourself.
Template code
<div>
{% slot main %}
</div>
<div>
{% slot sidebar %}
</div>
Node.js code
context.slots = {
main: [
"<h1>This is a paragraph as a normal string.</h1>", // String
{ tagname: 'analytics', // Widget object
uaCode: 'UA-XXXXX-X' },
],
sidebar: [
"<h3>Navigation</h3>", // String
{ tagname: 'navigation', // Widget object
links: [
'/home',
'/about',
'/kittens'
]}
]
}
context.widgets = {
analytics: function (context) {
// this inside widget functions is bound to the widget object
return "<script>..." + this.uaCode + "...</script>";
},
navigation: function (context) {
var i, html = "";
for (i=0; i<this.links; i++)
html += "<a href='" + links[i] + "'>" + links[i] + "</a>";
return html;
}
}
template.render(context)
Result
<div>
<h1>This is a paragraph as a normal string.</h1>
<script>...UA-XXXXX-X...</script>
</div>
<div>
<h3>Navigation</h3>
<a href='/home'>/home</a>
<a href='/about'>/about</a>
<a href='/kittens'>/kittens</a>
</div>
License
(The MIT License)
Copyright (c) 2010 Dusko Jordanovski
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the 'Software'), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED 'AS IS', WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.