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    Inject Custom JavaScript Into a Gatsby Site

    Steven MercatanteSteven Mercatante

    Learn how to add custom JavaScript to your Gatsby's main HTML.



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    Instructor: We need to make a copy of the html JavaScript file from Gatsby's cache and move it into our source directory. Open up html.js. You'll see that this is what Gatsby auto-generates for us.

    For this example, I just want to add a basic console log just so we can see our custom JavaScript being injected. When I refresh my site, I expect to see the new console log statement, but it's not showing up. The reason is because we're not working with an actual html file here. We're still working with a JavaScript file.

    We need to inject the JavaScript in a way that React allows us to. We can do that by using React's dangerouslySetinnerHTML attribute on the script tag.

    Now, when we refresh our site, we see our custom JavaScript.