caolan/pithy

Pithy.js

An internal DSL for generating HTML in JavaScript.

Examples

Basic elements

html.div('#main', [
    html.h1(null, 'Hello, world!'),
    html.img({src: 'foo.jpg'})
]);

<div id="main">
    <h1>Hello, world!</h1>
    <img src="foo.jpg"/>
</div>

Loops etc.

Using Underscore.js or similar:

function todoItem(item) {
    return html.li({rel: item.id}, [
        html.div('.title', item.title),
        html.button('.destroy', 'delete')
    ]);
}

function todoList(list) {
    return html.ul('.todo-list', _.map(list, todoItem));
}

todoList([
    {id: 1, title: 'item one'},
    {id: 2, title: 'item two'},
    {id: 3, title: 'item three'}
]);

<ul class="todo-list">
    <li rel="1">
        <div class="title">item one</div>
        <button class="destroy">delete</button>
    </li>
    <li rel="2">
        <div class="title">item two</div>
        <button class="destroy">delete</button>
    </li>
    <li rel="3">
        <div class="title">item three</div>
        <button class="destroy">delete</button>
    </li>
</div>

Why use an internal DSL?

• It's a more convenient and safer alternative to string contatenation
• Very flexible, you can use all the power of JavaScript functions and control structures
• For small bits of HTML you might not want to switch contexts from code to a template
• Easier to debug than a templating engine
• You get full tool-chain support:
  • editor support: syntax highlighting, code tools etc etc
  • code analyzers: jslint, jshint
  • testing/coverage tools

When to use?

• Consider using where you might currently use string concatenation
• Avoid using for large HTML documents or in places where speed is critical
• Good for small snippets used for client-side page updates
• Bad for generating huge amounts of HTML on the server

Usage

I like to alias the 'pithy' library as 'html':

var html = require('pithy');

You can then just use html.tagname as a function to create the appropriate element. Please note, you actually get a html.SafeString object back, not a native JavaScript String. This might mess up your isString() tests. If you have a workaround please send a pull-request.

There is also a html.escape() function for escaping HTML (returns a html.SafeString). It will not escape a value that is already a html.SafeString object.