78-helmet 中文文档教程
React Helmet
这个可重用的 React 组件将管理您对文档头部的所有更改。
Helmet 采用 纯 HTML 标签并输出 纯 HTML 标签。 它非常简单,并且对 React 初学者友好。
Example
import React from "react";
import {Helmet} from "react-helmet";
class Application extends React.Component {
render () {
return (
<div className="application">
<Helmet>
<meta charSet="utf-8" />
<title>My Title</title>
<link rel="canonical" href="http://mysite.com/example" />
</Helmet>
...
</div>
);
}
};
嵌套或后面的组件将覆盖重复的更改:
<Parent>
<Helmet>
<title>My Title</title>
<meta name="description" content="Helmet application" />
</Helmet>
<Child>
<Helmet>
<title>Nested Title</title>
<meta name="description" content="Nested component" />
</Helmet>
</Child>
</Parent>
输出:
<head>
<title>Nested Title</title>
<meta name="description" content="Nested component">
</head>
请参阅下面的完整参考指南。
Features
- Supports all valid head tags:
title
,base
,meta
,link
,script
,noscript
, andstyle
tags. - Supports attributes for
body
,html
andtitle
tags. - Supports server-side rendering.
- Nested components override duplicate head changes.
- Duplicate head changes are preserved when specified in the same component (support for tags like "apple-touch-icon").
- Callback for tracking DOM changes.
Compatibility
Helmet 5 与以前的 Helmet 版本完全向后兼容,因此您可以随时升级而不必担心破坏性更改。 我们鼓励您将您的代码更新为我们更具语义的 API,但请按照您自己的节奏随意进行。
Installation
Yarn:
yarn add react-helmet
npm:
npm install --save react-helmet
Server Usage
在服务端使用,在ReactDOMServer.renderToString
或ReactDOMServer.renderToStaticMarkup
之后调用Helmet.renderStatic()
获取头部数据用于您的预渲染。
因为此组件会跟踪安装的实例,您必须确保在服务器上调用 renderStatic
,否则会发生内存泄漏。
ReactDOMServer.renderToString(<Handler />);
const helmet = Helmet.renderStatic();
此 helmet
实例包含以下属性:
base
bodyAttributes
htmlAttributes
link
meta
noscript
script
style
title
每个属性包含 toComponent()
和 toString()
方法。 使用适合您的环境的任何一个。 对于属性,在 toComponent()
返回的对象上使用 JSX 扩展运算符。 例如:
As string output
const html = `
<!doctype html>
<html ${helmet.htmlAttributes.toString()}>
<head>
${helmet.title.toString()}
${helmet.meta.toString()}
${helmet.link.toString()}
</head>
<body ${helmet.bodyAttributes.toString()}>
<div id="content">
// React stuff here
</div>
</body>
</html>
`;
As React components
function HTML () {
const htmlAttrs = helmet.htmlAttributes.toComponent();
const bodyAttrs = helmet.bodyAttributes.toComponent();
return (
<html {...htmlAttrs}>
<head>
{helmet.title.toComponent()}
{helmet.meta.toComponent()}
{helmet.link.toComponent()}
</head>
<body {...bodyAttrs}>
<div id="content">
// React stuff here
</div>
</body>
</html>
);
}
Reference Guide
<Helmet
{/* (optional) set to false to disable string encoding (server-only) */}
encodeSpecialCharacters={true}
{/*
(optional) Useful when you want titles to inherit from a template:
<Helmet
titleTemplate="%s | MyAwesomeWebsite.com"
>
<title>Nested Title</title>
</Helmet>
outputs:
<head>
<title>Nested Title | MyAwesomeWebsite.com</title>
</head>
*/}
titleTemplate="MySite.com - %s"
{/*
(optional) used as a fallback when a template exists but a title is not defined
<Helmet
defaultTitle="My Site"
titleTemplate="My Site - %s"
/>
outputs:
<head>
<title>My Site</title>
</head>
*/}
defaultTitle="My Default Title"
{/* (optional) callback that tracks DOM changes */}
onChangeClientState={(newState, addedTags, removedTags) => console.log(newState, addedTags, removedTags)}
>
{/* html attributes */}
<html lang="en" amp />
{/* body attributes */}
<body className="root" />
{/* title attributes and value */}
<title itemProp="name" lang="en">My Plain Title or {`dynamic`} title</title>
{/* base element */}
<base target="_blank" href="http://mysite.com/" />
{/* multiple meta elements */}
<meta name="description" content="Helmet application" />
<meta property="og:type" content="article" />
{/* multiple link elements */}
<link rel="canonical" href="http://mysite.com/example" />
<link rel="apple-touch-icon" href="http://mysite.com/img/apple-touch-icon-57x57.png" />
<link rel="apple-touch-icon" sizes-"72x72" href="http://mysite.com/img/apple-touch-icon-72x72.png" />
{locales.map((locale) => {
<link rel="alternate" href="http://example.com/{locale}" hrefLang={locale} key={locale}/>
})}
{/* multiple script elements */}
<script src="http://include.com/pathtojs.js" type="text/javascript" />
{/* inline script elements */}
<script type="application/ld+json">{`
{
"@context": "http://schema.org"
}
`}</script>
{/* noscript elements */}
<noscript>{`
<link rel="stylesheet" type="text/css" href="foo.css" />
`}</noscript>
{/* inline style elements */}
<style type="text/css">{`
body {
background-color: blue;
}
p {
font-size: 12px;
}
`}</style>
</Helmet>
Contributing to this project
请花点时间查看贡献指南。
License
麻省理工学院
React Helmet
This reusable React component will manage all of your changes to the document head.
Helmet takes plain HTML tags and outputs plain HTML tags. It's dead simple, and React beginner friendly.
Example
import React from "react";
import {Helmet} from "react-helmet";
class Application extends React.Component {
render () {
return (
<div className="application">
<Helmet>
<meta charSet="utf-8" />
<title>My Title</title>
<link rel="canonical" href="http://mysite.com/example" />
</Helmet>
...
</div>
);
}
};
Nested or latter components will override duplicate changes:
<Parent>
<Helmet>
<title>My Title</title>
<meta name="description" content="Helmet application" />
</Helmet>
<Child>
<Helmet>
<title>Nested Title</title>
<meta name="description" content="Nested component" />
</Helmet>
</Child>
</Parent>
outputs:
<head>
<title>Nested Title</title>
<meta name="description" content="Nested component">
</head>
See below for a full reference guide.
Features
- Supports all valid head tags:
title
,base
,meta
,link
,script
,noscript
, andstyle
tags. - Supports attributes for
body
,html
andtitle
tags. - Supports server-side rendering.
- Nested components override duplicate head changes.
- Duplicate head changes are preserved when specified in the same component (support for tags like "apple-touch-icon").
- Callback for tracking DOM changes.
Compatibility
Helmet 5 is fully backward-compatible with previous Helmet releases, so you can upgrade at any time without fear of breaking changes. We encourage you to update your code to our more semantic API, but please feel free to do so at your own pace.
Installation
Yarn:
yarn add react-helmet
npm:
npm install --save react-helmet
Server Usage
To use on the server, call Helmet.renderStatic()
after ReactDOMServer.renderToString
or ReactDOMServer.renderToStaticMarkup
to get the head data for use in your prerender.
Because this component keeps track of mounted instances, you have to make sure to call renderStatic
on server, or you'll get a memory leak.
ReactDOMServer.renderToString(<Handler />);
const helmet = Helmet.renderStatic();
This helmet
instance contains the following properties:
base
bodyAttributes
htmlAttributes
link
meta
noscript
script
style
title
Each property contains toComponent()
and toString()
methods. Use whichever is appropriate for your environment. For attributes, use the JSX spread operator on the object returned by toComponent()
. E.g:
As string output
const html = `
<!doctype html>
<html ${helmet.htmlAttributes.toString()}>
<head>
${helmet.title.toString()}
${helmet.meta.toString()}
${helmet.link.toString()}
</head>
<body ${helmet.bodyAttributes.toString()}>
<div id="content">
// React stuff here
</div>
</body>
</html>
`;
As React components
function HTML () {
const htmlAttrs = helmet.htmlAttributes.toComponent();
const bodyAttrs = helmet.bodyAttributes.toComponent();
return (
<html {...htmlAttrs}>
<head>
{helmet.title.toComponent()}
{helmet.meta.toComponent()}
{helmet.link.toComponent()}
</head>
<body {...bodyAttrs}>
<div id="content">
// React stuff here
</div>
</body>
</html>
);
}
Reference Guide
<Helmet
{/* (optional) set to false to disable string encoding (server-only) */}
encodeSpecialCharacters={true}
{/*
(optional) Useful when you want titles to inherit from a template:
<Helmet
titleTemplate="%s | MyAwesomeWebsite.com"
>
<title>Nested Title</title>
</Helmet>
outputs:
<head>
<title>Nested Title | MyAwesomeWebsite.com</title>
</head>
*/}
titleTemplate="MySite.com - %s"
{/*
(optional) used as a fallback when a template exists but a title is not defined
<Helmet
defaultTitle="My Site"
titleTemplate="My Site - %s"
/>
outputs:
<head>
<title>My Site</title>
</head>
*/}
defaultTitle="My Default Title"
{/* (optional) callback that tracks DOM changes */}
onChangeClientState={(newState, addedTags, removedTags) => console.log(newState, addedTags, removedTags)}
>
{/* html attributes */}
<html lang="en" amp />
{/* body attributes */}
<body className="root" />
{/* title attributes and value */}
<title itemProp="name" lang="en">My Plain Title or {`dynamic`} title</title>
{/* base element */}
<base target="_blank" href="http://mysite.com/" />
{/* multiple meta elements */}
<meta name="description" content="Helmet application" />
<meta property="og:type" content="article" />
{/* multiple link elements */}
<link rel="canonical" href="http://mysite.com/example" />
<link rel="apple-touch-icon" href="http://mysite.com/img/apple-touch-icon-57x57.png" />
<link rel="apple-touch-icon" sizes-"72x72" href="http://mysite.com/img/apple-touch-icon-72x72.png" />
{locales.map((locale) => {
<link rel="alternate" href="http://example.com/{locale}" hrefLang={locale} key={locale}/>
})}
{/* multiple script elements */}
<script src="http://include.com/pathtojs.js" type="text/javascript" />
{/* inline script elements */}
<script type="application/ld+json">{`
{
"@context": "http://schema.org"
}
`}</script>
{/* noscript elements */}
<noscript>{`
<link rel="stylesheet" type="text/css" href="foo.css" />
`}</noscript>
{/* inline style elements */}
<style type="text/css">{`
body {
background-color: blue;
}
p {
font-size: 12px;
}
`}</style>
</Helmet>
Contributing to this project
Please take a moment to review the guidelines for contributing.
License
MIT