Lib.rs

› Rust 模式 › unhtml
#html #deserializer #unhtml

nightly unhtml_util

为 unhtml 提供一些实用特性和函数

由 xixi 和 2 位贡献者 编写

1 个不稳定版本

0.1.0 2018年11月28日

37 in #deserializer

MIT 许可证

15KB
431 行

一个魔法 HTML 解析器。

Stable Test Rust Docs Crate version Download License: MIT

目录

派生目标

结构体

基本用法

#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
#[html(selector = "#test")]
struct SingleUser {
    #[html(selector = "p:nth-child(1)", attr = "inner")]
    name: String,

    #[html(selector = "p:nth-child(2)", attr = "inner")]
    age: u8,

    #[html(selector = "p:nth-child(3)", attr = "inner")]
    like_lemon: bool,
}

let user = SingleUser::from_html(r#"<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div id="test">
        <div>
            <p>Hexilee</p>
            <p>20</p>
            <p>true</p>
        </div>
    </div>
</body>
</html>"#).unwrap();
assert_eq!("Hexilee", &user.name);
assert_eq!(20, user.age);
assert!(user.like_lemon);

属性

html

目标

derive target 或 field

规范

#[html(选择器= "...",attr= "...",默认= ...)]

selector、attr、default 或 html 本身可能是多余的。

这是有效的

#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};


#[derive(FromHtml)]
struct SingleString {
    value: String,
}

选择器

目标

derive target 或 field

文字类型

字符串

规范

选择器必须是一个有效的 CSS 选择器，无效的选择器将导致编译时恐慌

// panic
#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
#[html(selector = "<>")]
struct SingleUser {}

// panic
#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::*;

#[derive(FromHtml)]
struct SingleUser {
    #[html(selector = "<>", attr = "inner")]
    name: String,
}

如果选择多个元素且字段类型不是 Vec，则选择第一个


#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
#[html(selector = "a")]
struct Link {
    #[html(attr = "href")]
    href: String,

    #[html(attr = "inner")]
    value: String,
}

let link = Link::from_html(r#"
<a href="https://github.com">Github</a> 
<a href="https://google.com">Google</a> 
"#).unwrap();
assert_eq!("https://github.com", &link.href);
assert_eq!("Github", &link.value);
默认行为

根元素的 HTML


#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Link {
    #[html(attr = "href")]
    href: String,

    #[html(attr = "inner")]
    value: String,
}

let link = Link::from_html(r#"<a href="https://github.com">Github</a>"#).unwrap();
assert_eq!("https://github.com", &link.href);
assert_eq!("Github", &link.value);

attr

目标

字段

文字类型

字符串

规范
  • inner 指的是 innerHtml
  • 任何其他 attr 指的是 html 元素属性
#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Link {
    #[html(attr = "href")]
    href: String,

    #[html(attr = "inner")]
    value: String,
}

let link = Link::from_html(r#"<a href="https://github.com">Github</a>"#).unwrap();
assert_eq!("https://github.com", &link.href);
assert_eq!("Github", &link.value);
默认行为

整个元素的 HTML（不是 innerHtml！）

#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Link {
    #[html(attr = "href")]
    href: String,

    #[html(attr = "inner")]
    value: String,
    
    source: String,
}

let link = Link::from_html(r#"<a href="https://github.com">Github</a>"#).unwrap();
assert_eq!("https://github.com", &link.href);
assert_eq!("Github", &link.value);
assert_eq!(r#"<a href="https://github.com">Github</a>"#, &link.source);

默认

目标

字段

文字类型

任何 literal 类型

规范
  • 与 field 相同的类型
#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct DefaultUser {
    // invoke String::from_html
    #[html(selector = "#non-exist", default = "Hexilee")]
    name: String,

    // invoke u8::from<u8>
    #[html(default = 20)]
    age: u8,

    #[html(default = true)]
    like_lemon: bool,
}

let user = DefaultUser::from_html("<p></p>").unwrap();
assert_eq!("Hexilee", &user.name);
assert_eq!(20, user.age);
assert_eq!(-1000, user.assets);
assert!(user.like_lemon);
  • 字符串
#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Link {
    #[html(attr = "href")]
    href: String,

    #[html(attr = "inner")]
    value: String,
}

#[derive(FromHtml)]
struct Website {
    #[html(default = "10")]
    age: u8,

    #[html(default = "<a href='https://github.com'>Github</a>")]
    link: Link,
}

let website = Website::from_html("<p></p>").unwrap();
let link = website.link;
assert_eq!(10u8, website.age);
assert_eq!("https://github.com", &link.href);
assert_eq!("Github", &link.value);
默认行为

当选择无内容时返回 Err(unhtml::failure::Error)

// panic
#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Link {
    // no default
    #[html(attr = "href")]
    href: String,

    #[html(attr = "inner")]
    value: String,
}

let link = Link::from_html(r#"<a>Github</a>"#).unwrap();

字段类型

实现 FromHtml 的任何类型，不使用泛型
// panic
#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Link {
    // no default
    #[html(attr = "href")]
    href: &str,
}

// panic
#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Website {
    // no default
    #[html(attr = "href")]
    hrefs: std::collections::LinkedList<String>,
}

// panic
#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Website {
    // no default
    #[html(attr = "href")]
    hrefs: [String],
}
Vec

应使用 use unhtml::VecFromHtml

extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml, VecFromHtml};

#[derive(FromHtml)]
struct TestUser {
    #[html(selector = "p:nth-child(1)", attr = "inner")]
    name: String,

    #[html(selector = "p:nth-child(2)", attr = "inner")]
    age: u8,

    #[html(selector = "p:nth-child(3)", attr = "inner")]
    like_lemon: bool,
}

#[derive(FromHtml)]
#[html(selector = "#test")]
struct TestUsers {
    #[html(selector = "div")]
    users: Vec<TestUser>,
}

let users = TestUsers::from_html(r#"<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div id="test">
        <div>
            <p>Hexilee</p>
            <p>20</p>
            <p>true</p>
        </div>
        <div>
            <p>BigBrother</p>
            <p>21</p>
            <p>false</p>
        </div>
    </div>
</body>
</html>"#).unwrap();
let hexilee = &users.users[0];
let big_brother = &users.users[1];
assert_eq!("Hexilee", &hexilee.name);
assert_eq!(20, hexilee.age);
assert!(hexilee.like_lemon);
assert_eq!("BigBrother", &big_brother.name);
assert_eq!(21, big_brother.age);
assert!(!big_brother.like_lemon);

如 crate unhtml 的文档所示，如果您想直接使用 Vec<TestUser>，则可以这样做：

extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, VecFromHtml};

#[derive(FromHtml)]
struct TestUser {
    #[html(selector = "p:nth-child(1)", attr = "inner")]
    name: String,

    #[html(selector = "p:nth-child(2)", attr = "inner")]
    age: u8,

    #[html(selector = "p:nth-child(3)", attr = "inner")]
    like_lemon: bool,
}

let users = Vec::<TestUser>::from_html("#test > div", r#"<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div id="test">
        <div>
            <p>Hexilee</p>
            <p>20</p>
            <p>true</p>
        </div>
        <div>
            <p>BigBrother</p>
            <p>21</p>
            <p>false</p>
        </div>
    </div>
</body>
</html>"#).unwrap();
let hexilee = &users[0];
let big_brother = &users[1];
assert_eq!("Hexilee", &hexilee.name);
assert_eq!(20, hexilee.age);
assert!(hexilee.like_lemon);
assert_eq!("BigBrother", &big_brother.name);
assert_eq!(21, big_brother.age);
assert!(!big_brother.like_lemon);

源 HTML

带有顶级选择器

所有源 HTML 都将被解析为 fragment。顶级元素是 html，并且没有 DOCTYPE、head 或 body。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div id="test">
        <div>
            <p>Hexilee</p>
            <p>20</p>
            <p>true</p>
        </div>
    </div>
</body>
</html>

将被解析为

<html lang="en">
    <meta charset="UTF-8">
    <title>Title</title>
    <div id="test">
        <div>
            <p>Hexilee</p>
            <p>20</p>
            <p>true</p>
        </div>
    </div>
</html>

和

<p>Hexilee</p>

将被解析为

<html>
    <p>Hexilee</p>
</html>    


// panic

extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Document {
    // no default
    #[html(selector = "head")]
    head: String,

    #[html(selector = "body")]
    body: String,
}

let dicument = Document::from_html(r#"<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div id="test">
        <div>
            <p>Hexilee</p>
            <p>20</p>
            <p>true</p>
        </div>
    </div>
</body>
</html>"#).unwrap();
没有顶级选择器

当派生结构体没有 top selector 时，所有源 HTML 都将被解析为 纯 fragment。没有 DOCTYPE、html、head 或 body。

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>
    <div id="test">
        <div>
            <p>Hexilee</p>
            <p>20</p>
            <p>true</p>
        </div>
    </div>
</body>
</html>

将被解析为

<meta charset="UTF-8">
<title>Title</title>
<div id="test">
   <div>
       <p>Hexilee</p>
       <p>20</p>
       <p>true</p>
   </div>
</div>

和

<p>Hexilee</p>

将被解析为

<p>Hexilee</p>

#[macro_use]
extern crate unhtml_derive;
extern crate unhtml;
use unhtml::{self, FromHtml};

#[derive(FromHtml)]
struct Link {
    #[html(attr = "href")]
    href: String,

    #[html(attr = "inner")]
    value: String,
}

let link = Link::from_html(r#"<a href="https://github.com">Github</a>"#).unwrap();
assert_eq!("https://github.com", &link.href);
assert_eq!("Github", &link.value);

依赖项

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