Crate h2s

Expand description

A declarative HTML parser library in Rust, that works like a deserializer from HTML to struct.

Example

use h2s::FromHtml;

#[derive(FromHtml, Debug, Eq, PartialEq)]
pub struct Page {
    #[h2s(select = "div > h1.blog-title")]
    blog_title: String,
    #[h2s(select = ".articles > div")]
    articles: Vec<Article>,
}

#[derive(FromHtml, Debug, Eq, PartialEq)]
pub struct Article {
    #[h2s(select = "h2 > a")]
    title: String,
    #[h2s(select = "div > span")]
    view_count: usize,
    #[h2s(select = "h2 > a", attr = "href")]
    url: String,
    #[h2s(select = "p.modified-date")]
    modified_date: Option<String>,
    #[h2s(select = "ul > li")]
    tags: Vec<String>,
}

let html = r#"
<html>
<body>
<div>
    <h1 class="blog-title">My tech blog</h1>
    <div class="articles">
        <div>
            <h2><a href="https://example.com/1">article1</a></h2>
            <div><span>901</span> Views</div>
            <ul><li>Tag1</li><li>Tag2</li></ul>
            <p class="modified-date">2020-05-01</p>
        </div>
        <div>
            <h2><a href="https://example.com/2">article2</a></h2>
            <div><span>849</span> Views</div>
            <ul></ul>
            <p class="modified-date">2020-03-30</p>
        </div>
        <div>
            <h2><a href="https://example.com/3">article3</a></h2>
            <div><span>103</span> Views</div>
            <ul><li>Tag3</li></ul>
        </div>
    </div>
</div>
</body>
</html>
"#;

let page: Page = h2s::parse(html).unwrap();
assert_eq!(page, Page {
    blog_title: "My tech blog".into(),
    articles: vec![
        Article {
            title: "article1".into(),
            url: "https://example.com/1".into(),
            view_count: 901,
            modified_date: Some("2020-05-01".into()),
            tags: vec!["Tag1".into(), "Tag2".into()]
        },
        Article {
            title: "article2".into(),
            url: "https://example.com/2".into(),
            view_count: 849,
            modified_date: Some("2020-03-30".into()),
            tags: vec![]
        },
        Article {
            title: "article3".into(),
            url: "https://example.com/3".into(),
            view_count: 103,
            modified_date: None,
            tags: vec!["Tag3".into()]
        },
    ]
});

Supported types

You can use the following types as a field value of the struct to parse.

Basic types

String
Numeric types ( usize, i64, NonZeroU32, … )
And more built-in supported types (List)
Or you can use any types by implementing yourself (Example)

Container types (where `T` is a basic type)

[T;N]
Option<T>
Vec<T>

Modules

backend

You can select backend HTML parser library to use, or you can also implement custom backend by yourself.

display

All implementations of Display trait. Defining human-readable string is a different context from HTML-parsing process, so we are separating it and aggregating implementations here

from_html

Implementations of FromHtml trait

from_text

macro_utils

A set of internal utility methods that will be used in the auto-generated code on FromHtml derive macro. These methods are shorthands to reduce codes in the quote! macro. It improves development experience with IDE. You wouldn’t call these methods directly in your code.

mapper

text_extractor

transformer