How to include local javascript on a Gatsby page?

Question

I\'m a total React newbie and I guess there is something fundamental I don\'t quite understand here. A default Gatsby page looks like this. Is there a way to use a local .js

Answer 1

There are many ways to add scripts in GatsbyJS...

To execute a script on a specific page

• create your script.js file and place it anywhere inside your /src folder.

• go to the page you want to excute the script in (e.g. /pages/myPage.js ), and use require() to execute it inside useEffect() like this:

   useEffect(() => {
     // This runs the script
     const myScript = require('../script.js')
   }, [])
  
   return <div />
  

• To run it on client-side, you could check the window object inside your script.js file:

   if(typeof window !== 'undefined' && window.document) {
      // Your script here...
   }
  

If you want to execute a script globally in (every component/page) you could use html.js file.

• first, you'll have to extract the file (in case you didn't) by running:

cp .cache/default-html.js src/html.js

• inside your html.js file:

<script dangerouslySetInnerHTML= {{ __html:`
  // your script here...
`}} />

Answer 2

After several hours of frustration I finally stumbled upon discussion on GitHub that solved this for me. In Gatsby, there is a thing called static folder, for which one use case is including a small script outside of the bundled code.

Anyone else in the same situation, try proceeding as follows:

1. Create a folder static to the root of your project.

2. Put your script script.js in the folder static.

3. Include the script in your react dom with react-helmet.

So in the case of the code I posted in my original question, for instance:

import React from "react"
import Helmet from "react-helmet"
import { withPrefix, Link } from "gatsby"

import Layout from "../components/layout"
import Image from "../components/image"
import SEO from "../components/seo"

const IndexPage = () => (
  <Layout>
    <Helmet>
        <script src={withPrefix('script.js')} type="text/javascript" />
    </Helmet>
    <SEO title="Home" keywords={[`gatsby`, `application`, `react`]} />
    <h1>Hi people</h1>
    <p>Welcome to your new Gatsby site.</p>
    <p>Now go build something great.</p>
    <div style={{ maxWidth: `300px`, marginBottom: `1.45rem` }}>
      <Image />
    </div>
    <Link to="/page-2/">Go to page 2</Link>
  </Layout>
)

Notice the imports

import Helmet from "react-helmet"
import { withPrefix, Link } from "gatsby"

and the script element.

<Helmet>
    <script src={withPrefix('script.js')} type="text/javascript" />
</Helmet>

This would have saved hours of my time, hopefully this does it for someone else.

Answer 3

React works with dynamic DOM. But for rendering it by browser, your web server should send a static index page, where React will be included as another script tag.

So, take a look on your index.html page, which you can find in public folder. There you could insert your script tag in the header section, for example.

Answer 4

You can do this very easily with the Gatsby plugin "gatsby-plugin-load-script."

Simply do this:

1. Create a folder named static at the root of your gatsby app
2. Place your script in it
3. Add the following configuration in gatsby-config.js

    {
      resolve: 'gatsby-plugin-load-script',
      options: {
        src: '/test-script.js', // Change to the script filename
      },
    },

Answer 5

Just create gatsby-ssr.js file on root folder

and add the following pattern for your scripts folder

import React from 'react'

export const onRenderBody = ({ setPostBodyComponents }) => {
  setPostBodyComponents([
    <script
      key="https://code.jquery.com/jquery-3.2.1.slim.min.js"
      src="https://code.jquery.com/jquery-3.2.1.slim.min.js"
      integrity="sha384-KJ3o2DKtIkvYIK3UENzmM7KCkRr/rE9/Qpg6aAZGJwFDMVNA/GpGFF93hXpG5KkN"
      crossOrigin="anonymous"
      defer
    />,
    <script
      key="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js"
      src="https://cdnjs.cloudflare.com/ajax/libs/popper.js/1.12.9/umd/popper.min.js"
      integrity="sha384-ApNbgh9B+Y1QKtv3Rn7W3mgPxhU9K/ScQsAP7hUibX39j7fakFPskvXusvfa0b4Q"
      crossOrigin="anonymous"
      defer
    />,
    <script
      key="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"
      src="https://maxcdn.bootstrapcdn.com/bootstrap/4.0.0/js/bootstrap.min.js"
      integrity="sha384-JZR6Spejh4U02d8jOt6vLEHfe/JQGiRRSQQxSfFWpi1MquVdAyjUar5+76PVCmYl"
      crossOrigin="anonymous"
      defer
    />
  ])
}

Then, you at the end of dom you'll see the links to scripts

Answer 6

Gatsby uses html.js in the src folder. Not index.html like most react projects.

Example html.js file:

import React from "react"
import PropTypes from "prop-types"

export default class HTML extends React.Component {
  render() {
    return (
      <html {...this.props.htmlAttributes}>
        <head>
          <meta charSet="utf-8" />
          <meta httpEquiv="x-ua-compatible" content="ie=edge" />
          <meta
            name="viewport"
            content="width=device-width, initial-scale=1, shrink-to-fit=no"
          />
          {this.props.headComponents}
        </head>
        <body {...this.props.bodyAttributes}>
          {this.props.preBodyComponents}
          <div
            key={`body`}
            id="___gatsby"
            dangerouslySetInnerHTML={{ __html: this.props.body }}
          />
          {this.props.postBodyComponents}
        </body>
      </html>
    )
  }
}

HTML.propTypes = {
  htmlAttributes: PropTypes.object,
  headComponents: PropTypes.array,
  bodyAttributes: PropTypes.object,
  preBodyComponents: PropTypes.array,
  body: PropTypes.string,
  postBodyComponents: PropTypes.array,
}

For adding custom Javascript using dangerouslySetInnerHTML inside src/html.js:

<script
  dangerouslySetInnerHTML={{
    __html: `
            var name = 'world';
            console.log('Hello ' + name);
        `,
  }}
/>

You can try adding your js there but, note that your js may not work as expected. You can always look into react-helmet for more dynamic apps and adding scripts to <head>.

Gatsby Documentation: https://www.gatsbyjs.org/docs/custom-html/