[][src]Crate html_minifier

HTML Minifier

This library can help you generate and minify your HTML code at the same time. It also supports to minify JS and CSS in <style>, <script> elements, and ignores the minification of <pre>, <code> and <textarea> elements.

HTML is minified by the following rules:

  • ASCII control characters (0x00-0x08, 0x11-0x1F, 0x7F) are always removed.
  • Comments can be optionally removed. (removed by default)
  • Useless whitespaces (spaces, tabs and newlines) are removed.
  • Whitespaces (spaces, tabs and newlines) are converted to a single '\x20' or a single '\n', if possible.
  • Empty attribute values are collapsed. (e.g <input readonly=""> => <input readonly> )
  • The inner HTML of all elements is minified except for the following elements:
    • <pre>
    • <textarea>
    • <code> (optionally, minified by default)
    • <style> (if the type attribute is unsupported)
    • <script> (if the type attribute is unsupported)
  • JS code and CSS code in <script> and <style> elements are minified by minifier.

The original (non-minified) HTML doesn't need to be completely generated before using this library because this library doesn't do any deserialization to create DOMs.

In earier versions, this libaray tried to make HTML inline (e.g. <a>1</a>\n /\n <a>2</a> => <a>1</a> / <a>2</a>). With this feature, CJ characters need to be checked, otherwise 中\n文 will be minified to 中 文, which is incorrect.

After version 3.0.0, this libaray doesn't try to make HTML inline anymore in favor of better performance by removing UTF-8 calculation. Moreover, with this change, it allows the input texts to be encoded not only in ASCII or UTF-8 but also in any other self-synchronizing encoding.

Examples

extern crate html_minifier;

use html_minifier::HTMLMinifier;

let mut html_minifier = HTMLMinifier::new();

html_minifier.digest("<!DOCTYPE html>   <html  ").unwrap();
html_minifier.digest("lang=  en >").unwrap();
html_minifier.digest("
<head>
    <meta name=viewport>
</head>
").unwrap();
html_minifier.digest("
<body class=' container   bg-light '>
    <input type='text' value='123   456' readonly=''  />

    123456
    <b>big</b> 789
    ab
    c
    中文
    字
</body>
").unwrap();
html_minifier.digest("</html  >").unwrap();

assert_eq!("<!DOCTYPE html> <html lang=en>
<head>
<meta name=viewport>
</head>
<body class='container bg-light'>
<input type='text' value='123   456' readonly/>
123456
<b>big</b> 789
ab
c
中文
字
</body>
</html>".as_bytes(), html_minifier.get_html());
extern crate html_minifier;

use html_minifier::HTMLMinifier;

let mut html_minifier = HTMLMinifier::new();

html_minifier.digest("<pre  >   Hello  world!   </pre  >").unwrap();

assert_eq!(b"<pre>   Hello  world!   </pre>", html_minifier.get_html());
extern crate html_minifier;

use html_minifier::HTMLMinifier;

let mut html_minifier = HTMLMinifier::new();

html_minifier.digest("<script type='  application/javascript '>   alert('Hello!')    ;   </script>").unwrap();

assert_eq!("<script type='application/javascript'>alert('Hello!')</script>".as_bytes(), html_minifier.get_html());

Write HTML to a Writer

If you don't want to store your HTML in memory (e.g. writing to a file instead), you can use the HTMLMinifierHelper struct which provides a low-level API that allows you to pass your output instance when invoking the digest method.

extern crate html_minifier;

use html_minifier::HTMLMinifierHelper;

use std::fs::File;
use std::io::Read;

let mut input_file = File::open("tests/data/w3schools.com_tryhow_css_example_website.htm").unwrap();
let mut output_file = File::create("tests/data/index.min.html").unwrap();

let mut buffer = [0u8; 256];

let mut html_minifier_helper = HTMLMinifierHelper::new();

loop {
    let c = input_file.read(&mut buffer).unwrap();

    if c == 0 {
        break;
    }

    html_minifier_helper.digest(&buffer[..c], &mut output_file).unwrap();
}

No Std

Disable the default features to compile this crate without std.

[dependencies.html-minifier]
version = "*"
default-features = false

Modules

css
js

Structs

HTMLMinifier

This struct helps you generate and minify your HTML code in the same time. The output destination is inside this struct.

HTMLMinifierHelper

This struct helps you generate and minify your HTML code in the same time. The output destination is outside this struct.

Enums

HTMLMinifierError

Errors for HTMLMinifier.

Traits

HTMLWriter

Implement this trait to build a HTML writer.

Functions

minify

Minify HTML.