HTML Minifier
====================
[](https://travis-ci.org/magiclen/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 between CJ characters are checked)
* 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](https://crates.io/crates/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.
## Examples
```rust
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());
```
```rust
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());
```
```rust
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.
```rust
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.
```toml
[dependencies.html-minifier]
version = "*"
default-features = false
```
## Crates.io
https://crates.io/crates/html-minifier
## Documentation
https://docs.rs/html-minifier
## License
[MIT](LICENSE)