Key-Based Config

A script for interfacing with my Key-Based Config UI.

As of 2021-01-11. See the latest version.

This script should not be not be installed directly. It is a library for other scripts to include with the meta directive // @require https://update.greasyfork.org/scripts/419978/889804/Key-Based%20Config.js

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Wrap lines

// ==UserScript==
// @name        Key-Based Config
// @author      Callum Latham <[email protected]> (https://github.com/ctl2/key-based-config)
// @exclude     *
// @description A script for interfacing with my Key-Based Config UI.
// ==/UserScript==

let iframeExists = false;

function kbcConfigure(storageKey, title, metaTree) {

    return new Promise((resolve, reject) => {

        if (iframeExists) {
            reject(new Error("A key-based-config iFrame already exists."));
        } else if (typeof GM.getValue !== "function" || typeof GM.setValue !== "function") {
            reject(new Error("The key-based config script requires GM.getValue and GM.setValue permissions."));
        } else {

            iframeExists = true;
            const kbcSrc = "http://ctl-bucket-1.s3-website.eu-west-2.amazonaws.com/key-based-config";

            // Make iFrame
            let iframe = document.createElement("iframe");
            iframe.src = kbcSrc;
            iframe.style.position = "fixed";
            iframe.style.height = "100vh";
            iframe.style.width = "100vw";

            // Listen for iFrame communication
            window.addEventListener("message", async (message) => {
                switch (message.data.event) {
                    case "open":
                        // Pass initilisation data
                        const valueForest = await GM.getValue(storageKey);
                        iframe.contentWindow.postMessage({
                            title: title,
                            metaTree: metaTree,
                            valueForest: valueForest === undefined ? [] : valueForest
                        }, "*");
                        break;
                    case "change":
                        // Update stored value
                        GM.setValue(storageKey, message.data.valueForest);
                        break;
                    case "close":
                        // Close iFrame
                        iframeExists = false;
                        iframe.remove();
                        // Resolve promise
                        resolve(message.data.valueForest);
                        break;
                    default:
                        // No need to error the promise here; I'm probably just observing a message from another script
                        console.error("Unrecognised message 'event' value observed by key-based config script: '" + message.data.type + "'");
                }
            });

        }

    });

}