prettify

{{prettify}} handlebars helper for formatting (beautifying) HTML, JavaScript and CSS.

{{prettify}} handlebars helper for formatting (beautifying) HTML, JavaScript and CSS.

This helper depends on and extends js-beautify. Please visit and star that project to show your support.

Getting Started

In the root of the project in which you plan to use the helper, in the command line run:

npm i prettify --save

Use within your application with the following line of JavaScript:

var helpers = require('prettify');

Now your handlebars instance will have access to the {{prettify}} helper.

All options from js-beautify are available in this helper, as well as a few custom options that were specially created for this helper. The helper comes with some sensible defaults (in the humble opinion of the helper creator), but it's easy to customize them if you need to. Here are are two (convenient) ways to set options:

options hash: this is an easy way to set options on the helper, and it gives you the most granular control over how the helper renders content.
Assemble task options: if you use both Grunt and Assemble, you can define options in your project's Gruntfile.

options hash

By design, options define here will override options defined anywhere else.

{{#prettify indent=4}}
  {{> body }}
{{/prettify}}

"assemble" task options

The helper can be used without Grunt or Assemble. But if you happen to use these two awesome tools you can define options for the helper in your Gruntfile in the prettify sub-options for Assemble:

grunt.initConfig({
  assemble: {
    options: {
      prettify: {
        condense: true,
        padcomments: true,
        indent: 4
      }
    },
    ...
  }
});

Options defined in the Assemble task can be viewed as custom "global" defaults, which can be overridden by options defined in the options hash.

custom options

In addition to the options available from js-beautify, the following are custom options created specially for this helper.

mode

Type: String Default value: html (other options: js|css)

If you are formatting HTML, this does not need to be defined, but if you wish to format CSS or JavaScript you must specify either js or css respectively.

{{#prettify mode="js" indent=4}}
function foo(str) {return str;}
{{/prettify}}

Note that when you change the mode, the available and allowed options change as well. If you specify an option for the wrong mode, the helper may or may not throw an error, so be cautious. This can be a bit tricky if you're building a project that is using the {{prettify}} helper in several places with different modes. It's easy to forget that you have a layout wrapped like this:

{{#prettify indent=2}}
  {{> body }}
{{/prettify}}

and then do this on one of the pages that uses that layout:

{{#prettify mode="js" indent=4}}
function foo(str) {return str;}
{{/prettify}}

This won't throw an error, but the JavaScript inside the "js" block will be re-formatted by the outter instance of the helper. So based on this example the JavaScript in the "js" block will be indented to 2 spaces.

option defaults

Here are the available options and defaults for each mode.

"html" mode

These options are available by default.

{
  "indent_inner_html": false,   // Indent <head> and <body> sections 
  "indent_size": 2,             // Indentation size 
  "indent_char": " ",           // Indentation character. Can be an actual tab or space 
  "brace_style": "expand",      // collapse|expand|end-expand 
  "indent-scripts": "normal"    // keep|separate|normal 
  "wrap_line_length": 78,       // Maximum characters per line (0 disables this) 
  "unformatted": ["a", "sub", "sup", "b", "i", "u"], // List of tags that should not be reformatted (inline elements included by default) 
  "preserve_newlines": true,    // Preserve existing line-breaks 
  "max_preserve_newlines": 5,   // Maximum number of line-breaks to be preserved in one chunk 
 
  // custom options made for this helper 
  "indent": 2,          // convenience alias for indent_size 
  "contense": false,    // remove extra newlines missed by js-beautify. 
  "padcomments": false  // add an extra newline above each HTML code comment 
}

"js" mode

When mode is set to js, the following options are available:

{
  "indent_size": 2,
  "indent_char": " ",
  "indent_level": 0,
  "indent_with_tabs": false,
  "preserve_newlines": true,
  "max_preserve_newlines": 10,
  "jslint_happy": false,
  "brace_style": "collapse",
  "keep_array_indentation": false,
  "keep_function_indentation": false,
  "space_before_conditional": true,
  "break_chained_methods": false,
  "eval_code": false,
  "unescape_strings": false,
  "wrap_line_length": 0
}

"css" mode

When mode is set to css, the following options are available:

{
  "indent_size": 2,
  "indent_char": " "
}

<!DOCTYPE html>
<html lang="en">
  <head>
 
    <!-- code comment -->
    <meta charset="UTF-8">
    <title>Document</title>
  </head>
  <body>
    <h1>My Blog</h1>
    <h2>Post of the day</h2>
 
    <!-- scripts -->
    <a href="#">Read more...</a>
  </body>
</html>

Usage Examples

Usage with Assemble

Use this helper in a "parent" layout:

{{#prettify}}
  {{> body }}
{{/prettify}}

See nested layouts.

Indent Example

Before

Using the indent option:

Template: index.hbs

{{#prettify indent="2"}}
<!DOCTYPE html>
<html lang="en">
<head>
<meta charset="UTF-8">
<title>Document</title>
</head>
<body>
<h1>My Blog</h1>
<h2>Post of the day</h2>
<p>
Vestibulum posuere, quam sed bibendum posuere
Pellentesque habitant morbi tristique senectus
Pellentesque nulla augue, volutpat vitae
</p>
<a href="#">Read more...</a>
</body>
</html>
{{/prettify}}

After

Renders to:

<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8">
    <title>Document</title>
  </head>
  <body>
    <h1>My Blog</h1>
    <h2>Post of the day</h2>
    <p>
      Vestibulum posuere, quam sed bibendum posuere
      Pellentesque habitant morbi tristique senectus
      Pellentesque nulla augue, volutpat vitae
    </p>
    <a href="#">Read more...</a>
  </body>
</html>

Condense Example

Before

<!DOCTYPE html>
<html lang="en">
  <head>
 
    <!-- code comment -->
    <meta charset="UTF-8">
    <title>Document</title>
 
 
  </head>
 
 
  <body>
    <h1>My Blog</h1>
    <h2>Post of the day</h2>
 
 
    <!-- scripts -->
    <a href="#">Read more...</a>
 
 
  </body>
</html>

Example output with condensed: true:

After

<!DOCTYPE html>
<html lang="en">
  <head>
    <!-- code comment -->
    <meta charset="UTF-8">
    <title>Document</title>
  </head>
  <body>
    <h1>My Blog</h1>
    <h2>Post of the day</h2>
    <!-- scripts -->
    <a href="#">Read more...</a>
  </body>
</html>

Newlines

When used with condense, defining newlines: true will result in something like this:

<!DOCTYPE html>
<html lang="en">
  <head>
 
    <!-- code comment -->
    <meta charset="UTF-8">
    <title>Document</title>
  </head>
  <body>
    <h1>My Blog</h1>
    <h2>Post of the day</h2>
 
    <!-- scripts -->
    <a href="#">Read more...</a>
  </body>
</html>

Contributing

Please see the Contributing to Assemble guide for information on contributing to this project.

Author

handlebars-helpers
helpers: some great handlebars helpers that we decided not to include in the handlebars-helpers project, most likely because the code footprint was too big or the helper wasn't generic enough.
grunt-prettify