A React hook that lets you add script tags to a component. Useful when needing to load scripts for components in Framer X.

useScript.tsx

import * as React from "react"
import { useState, useEffect } from "react"

// Hook
let cachedScripts = []

export function useScript(src) {
    // Keeping track of script loaded and error state
    const [state, setState] = useState({
        loaded: false,
        error: false,
    })

    useEffect(() => {
        // If cachedScripts array already includes src that means another instance ...
        // ... of this hook already loaded this script, so no need to load again.
        if (cachedScripts.includes(src)) {
            setState({
                loaded: true,
                error: false,
            })
        } else {
            cachedScripts.push(src)

            // Create script
            let script = document.createElement("script")
            script.src = src
            script.async = true

            // Script event listener callbacks for load and error
            const onScriptLoad = () => {
                setState({
                    loaded: true,
                    error: false,
                })
            }

            const onScriptError = () => {
                // Remove from cachedScripts we can try loading again
                const index = cachedScripts.indexOf(src)
                if (index >= 0) cachedScripts.splice(index, 1)
                script.remove()

                setState({
                    loaded: true,
                    error: true,
                })
            }

            script.addEventListener("load", onScriptLoad)
            script.addEventListener("error", onScriptError)

            // Add script to document body
            document.body.appendChild(script)

            // Remove event listeners on cleanup
            return () => {
                script.removeEventListener("load", onScriptLoad)
                script.removeEventListener("error", onScriptError)
            }
        }
    }, [src]) // Only re-run effect if script src changes

    return [state.loaded, state.error]
}

What's the best way to execute a function after the script is loaded?

@AndrewTraub I would suggest using it in the useEffect from the example above. It returns a boolean if it's loaded, and if so, you can then do what you'd like from there.

what if the script exists as a project file and not a url? how would you modify the hook?

@ridhwaans I have a Framer Example that lets you choose either a URL or a local file using a property control in the component itself :)

You can see how it's set up here: https://github.com/framer/framer-bridge-stencil-kit/tree/master/code/utils

You can look into constants.tsx to see the actual util