What
Is Metadata? The Metadata
is data (information) about data and the Meta
tag provides metadata about the HTML document.
As An Example in HTML,
The Metadata
will not be displayed on the page, but will be machine parsable.
The Meta
elements are typically used to specify the following points:
1. The
page description,
2. The
page keywords,
3. The
page author of the document
4. The
page last modified
5. The
page viewport
6. The
page other metadata
Notes
- The <meta> tags always
inside the <head> element and meta tags always passed as name/value
pairs.
As An Example in HTML,
<head>
<meta charset="UTF-8">
<meta name="description" content="Free Web tutorials">
<meta name="keywords" content="HTML,CSS,XML,React, JavaScript">
<meta name="author" content="John Doe">
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
Now come to the points,
Follow the below example step by step to do the
same.
Step
1 – Install below command Using NPM,
npm install react-meta-tags --save
Note: You can also achieve this using React Helmet (a third party library)
Step
2 – Use MetaTag Component in your class Component
import React from 'react';
import MetaTags from 'react-meta-tags';
class Component1 extends React.Component {
render() {
return (
<div className="wrapper">
<MetaTags>
<title>Your Page 1</title>
<meta name="description" content="Your description here.." />
<meta property="og:title" content="Your App" />
<meta property="og:image" content="Your path/to/image.jpg" />
</MetaTags>
<div className="content"> Your Content here... </div>
</div>
)
}
}
Note: Define id on tags so if you navigate to
other page, older meta tags will be replaced/update by new ones.
Step
3 - ReactTitle Component:
If you just want to add title on a page you can
use ReactTitle instead.
import React from 'react';
import {ReactTitle} from 'react-meta-tags';
class Component2 extends React.Component {
render() {
return (
<div className="wrapper">
<ReactTitle title="Your Page 2"/>
<div className="content"> Your Page 2 Content </div>
</div>
)
}
}
The
Server Usage Example -
import MetaTagsServer from 'react-meta-tags/server';
import {MetaTagsContext} from 'react-meta-tags';
/* Import other required modules */
/* some serve specific code */
app.use((req, res) => {
//make sure you get a new metatags instance for each request
const metaTagsInstance = MetaTagsServer();
//react router match
match({
routes, location: req.url
}, (error, redirectLocation, renderProps) => {
let reactString;
try{
reactString = ReactDomServer.renderToString(
<Provider store={store}>
{/*** If you are using redux ***/}
{/* You have to pass extract method through MetaTagsContext so it can catch meta tags */}
<MetaTagsContext extract = {metaTagsInstance.extract}>
<RouterContext {...renderProps}/>
</MetaTagsContext>
</Provider>
);
}
catch(e){
res.status(500).send(e.stack);
return;
}
//get all title and metatags as string
const meta = metaTagsInstance.renderToString();
//append metatag string to your layout
const htmlStr = (`
<!doctype html>
<html lang="en-us">
<head>
<meta charSet="utf-8"/>
${meta}
</head>
<body>
<div id="content">
${reactString}
</div>
</body>
</html>
`);
res.status(200).send(layout);
});
});
As per the above code we have to do following for
server rendering options -
1. Import
MetaTagsServer form server
2. Import
MetaTagsContext form server
3. Create
a new instance of MetaTagsServer
4. Wrap
your component inside MetaTagsContext and pass extract method as props
5. Extract
Meta string using renderToString of MetaTagsServer instance
6. Append
Meta string to your html template.
JSX
Layout:
You might also be using React to define your
layout, in which case you can use getTags
method from metaTagsInstance. The layout part of above server side example will
look like this.
//get all title and metatags as React elements
const metaTags = metaTagsInstance.getTags();
//append metatag string to your layout
const layout = (
<html lang="en-us">
<head>
<meta charSet="utf-8"/>
{metaTags}
</head>
<body>
<div id="app" dangerouslySetInnerHTML={{__html: reactString}} />
</body>
</html>
);
const htmlStr = ReactDomServer.renderToString(layout);
res.status(200).send(htmlStr);
Download
the Source code - https://github.com/s-yadav/react-meta-tags
Note: You can also achieve this using React Helmet (a third partylibrary)
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Anil Singh is an author, tech blogger, and software programmer. Book writing, tech blogging is something do extra and Anil love doing it. For more detail, kindly refer to this link..
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