Skip to content

Latest commit

 

History

History
232 lines (171 loc) · 6.63 KB

README.md

File metadata and controls

232 lines (171 loc) · 6.63 KB
Raw

npm npm peer dependency version npm bundle size

React MetaTags Hook

React hook to manage HTML meta tags.

Supported Tags

  • title
  • description
  • charset
  • lang on the html tag
  • Any <meta> and <link>
  • Convenient way to set og:* and twitter:* meta tags

Features

  • Dependencies array, to better control the update of meta tags
  • When a component is unmounted, its meta tags are removed
  • When possible, existing tags are updated rather then re-created (even if created in different components)
  • DOM changes are debounced to avoid pointless consecutive updates
  • When used in sibling or nested components, meta tags are merged: last rendered components (i.e. the inner ones) overrides common meta tags.
  • Supports static HTML generation for Server Side Rendering
  • Typescript declarations

Install

  npm install react-metatags-hook

or

  yarn add react-metatags-hook

Example

import { useMetaTags } from 'react-metatags-hook';

const Component = ({ match }) => {
  const {
    params: { id },
    url,
  } = match;
  useMetaTags(
    {
      title: `Page Title`,
      description: `An interesting page description with id: ${id}`,
      charset: 'utf8',
      lang: 'en',
      metas: [
        { name: 'keywords', content: 'a, list, of, keywords' },
        { name: 'robots', content: 'index, follow' },
        { name: 'DC.Title', content: 'Dublin Core Title' },
        { name: 'url', content: `http://yourwebsite.com${url}` },
        { property: 'fb:app_id', content: '1234567890' },
        { 'http-equiv': 'Cache-Control', 'content': 'no-cache' },
      ],
      links: [
        { rel: 'canonical', href: 'http://yourwebsite.com' },
        { rel: 'icon', type: 'image/ico', href: '/favicon.ico' },
        {
          rel: 'apple-touch-icon',
          sizes: '72x72',
          type: 'image/png',
          href: '/apple-72.png',
        },
      ],
      openGraph: {
        title: 'Page Title',
        image: 'http://yourwebsite.com/ogimage.jpg',
        site_name: 'My Site',
      },
      twitter: {
        card: 'summary',
        creator: '@you',
        title: 'Page Title',
      },
    },
    [id, url]
  );
  return <>...</>;
};

Usage

useMetaTags(config: MetaTagsConfig, dependencies: any[])

MetaTagsConfig

interface MetaTagsConfig {
  title?: string;
  description?: string;
  lang?: string;
  charset?: string;
  metas?: MetaTag[];
  links?: LinkTag[];
  openGraph?: {
    [key: string]: string;
  };
  twitter?: {
    [key: string]: string;
  };
}

The config object accepts the following options:

title

Sets the <title> tag

description

Sets the <meta name="description" /> tag (convenient way, same as using metas)

lang

Sets <html> tag lang attribute

description

Sets the <meta charset="" /> tag (convenient way, same as using metas)

metas
interface MetaTag {
  'name'?: string;
  'property'?: string;
  'http-equiv'?: string;
  'content'?: string;
  [attributeKey: string]: string;
}

An array of object that represents the <meta /> tags

links
interface LinkTag {
  rel?: string;
  href?: string;
  size?: string;
  type?: string;
  media?: string;
  [attributeKey: string]: string;
}

An array of object that represents the <link /> tags

openGraph

A convenient method to set <meta property="og:*" /> meta tags. Accepts an object where the key is appended in the property attribute after the og: prefix, and the value is the content attribute of the meta.

twitter

A convenient method to set <meta property="twitter:*" /> meta tags. Accepts an object where the key is appended in the property attribute after the twitter: prefix, and the value is the content attribute of the meta.

What happens when used in multiple component or one component is unmounted

Nested and Sibling components

When used in nested components, metas defined in the children are merged with the ones defined in the parents. If the same meta are defined in both the parent and the children, children ones take precedence and overwrite parents ones. (see Tags creation and update for more details)

The same logic applies if used in sibling components: the last to render is the one that take precedence if same meta are defined.

Component unmount

When a component that uses this hook is unmounted, its metas definition are removed from a global list of metas and the metas definition is recalculated based on the definitions in other components. If some meta is not longer present in this resulting definition, the meta tag is removed from the DOM.

Tags creation and update

As just described, this library allows to overwrite tags in nested components, and updates existing tags if possible rather the creating new one. To do so, it has to identify when two tag definitions refers to the same tag (i.e. you want to change the <link rel='icon'/> when a component is mounted).

To identify when tags are unique, the following attributes are considered, and every time at least one of them is different, a new tag in the head is created.

Any Tag

  • id

<meta />

  • name
  • property
  • http-equiv
  • charset

<link />

  • rel
  • sizes

If this logic is unsatisfactory, please let me know and I'll be happy to improve it.

Server Side Rendering

This library exports the function generateStaticHtml that can be used to generate an HTML string of the meta tags created by this hook. Use it after ReactDOMServer.renderToString or ReactDOMServer.renderToStaticMarkup.

import { generateStaticHtml } from 'react-metatags-hook';

ReactDOMServer.renderToString(<App />);
const metaHTML = generateStaticHtml();

Is important to point out that the meta tags definitions are stored inside the library instance. This means that when different components are rendered into string in the same application instance (i.e. node server), the meta tags of the second render will add up to the definitions generated by the first render.

If this behavior is not the desired one, you can reset the meta tags definitions stored in the library instance using the resetMetaTags function.

import { generateStaticHtml, resetMetaTags } from 'react-metatags-hook';

ReactDOMServer.renderToString(<App />);
const metaHTML = generateStaticHtml();

resetMetaTags();
ReactDOMServer.renderToString(<AnotherApp />);
const anotherMetaHTML = generateStaticHtml();