aboutCfg.uc.js

// ==UserScript==
// @name           about:cfg
// @version        1.2.2
// @author         aminomancer
// @homepage       https://github.com/aminomancer/uc.css.js
// @description    Registers the old-school about:config page to the URL about:cfg. Intended for use with earthlng's aboutconfig module. That module restores the old about:config page, but gives it a long-winded URL like "chrome://userchromejs/content/aboutconfig/config.xhtml" which takes a lot longer to type in and doesn't look very elegant. This script finds the URL for that module and registers it to an about: URL so it counts as a chrome UI page. We're not just faking it, this makes it a bona-fide about: page. That means you can navigate to it by just typing about:cfg in the urlbar, and also means the identity icon will show it as a secure system page rather than a local file. It even means about:cfg will show up on the about:about page! This technically also makes using the aboutconfig module safer, because it denies the document access to some privileged stuff that it would have with a chrome:// URI. For instructions on installing earthlng's aboutconfig module for fx-autoconfig, please see the script description for App Menu about:config Button. This has only been tested with fx-autoconfig, but it may work with xiaoxiaoflood's loader. I don't think it will work with Alice0775's loader but I haven't tested it. Compatible with my appMenuAboutConfigButton.uc.js script. That button will automatically navigate to about:cfg if this script is installed. I recommend editing earthlng's config.xhtml file to remove line 13: title="about:config" This sets the tab title to about:config, which isn't necessary or desirable since we're changing the URL to about:cfg. Without the title attribute, firefox will automatically set the title to the tab's URL, which (with this script) is about:cfg.
// @license        This Source Code Form is subject to the terms of the Creative Commons Attribution-NonCommercial-ShareAlike International License, v. 4.0. If a copy of the CC BY-NC-SA 4.0 was not distributed with this file, You can obtain one at http://creativecommons.org/licenses/by-nc-sa/4.0/ or send a letter to Creative Commons, PO Box 1866, Mountain View, CA 94042, USA.
// @backgroundmodule
// ==/UserScript==

// user configuration
const config = {
    // the value to put after "about:" — if this is "cfg" then the final URl will be "about:cfg". if
    // you use this and my appMenuAboutConfigButton.uc.js script, and you want to change this
    // address for whatever reason, be sure to edit the urlOverride setting in that script so it
    // says "about:your-new-address"
    address: "cfg",

    // the script tries to automatically find earthlng's aboutconfig URL, e.g.
    // "chrome://userchrome/content/aboutconfig/config.xhtml" if you followed the instructions on my
    // repo for making it compatible with fx-autoconfig. alternatively, it should also be able to
    // find the URL if you use earthlng's autoconfig loader or xiaoxiaoflood's, and didn't modify
    // anything. if it's unable to find the URL for your particular setup, please find it yourself
    // and paste it here, *inside the quotes*
    pathOverride: "",
};

let { Services } = ChromeUtils.import("resource://gre/modules/Services.jsm");
let { classes: Cc, interfaces: Ci, manager: Cm, utils: Cu, results: Cr } = Components;
let registrar = Cm.QueryInterface(Ci.nsIComponentRegistrar);

function findAboutConfig() {
    if (config.pathOverride) return config.pathOverride;
    let dir = Services.dirsvc.get("UChrm", Ci.nsIFile);
    let appendFn = (nm) => dir.append(nm);

    // fx-autoconfig
    ["resources", "aboutconfig", "config.xhtml"].forEach(appendFn);
    if (dir.exists()) return "chrome://userchrome/content/aboutconfig/config.xhtml";

    // earthlng's loader
    dir = Services.dirsvc.get("UChrm", Ci.nsIFile);
    ["utils", "aboutconfig", "config.xhtml"].forEach(appendFn);
    if (dir.exists()) return "chrome://userchromejs/content/aboutconfig/config.xhtml";

    // xiaoxiaoflood's loader
    dir = Services.dirsvc.get("UChrm", Ci.nsIFile);
    ["utils", "aboutconfig", "aboutconfig.xhtml"].forEach(appendFn);
    if (dir.exists()) return "chrome://userchromejs/content/aboutconfig/aboutconfig.xhtml";

    // no about:config replacement found
    return false;
}

// generate a unique ID on every app launch. protection against the very unlikely possibility that a
// future update adds a component with the same class ID, which would break the script.
function generateFreeCID() {
    let uuid = Components.ID(
        Cc["@mozilla.org/uuid-generator;1"]
            .getService(Ci.nsIUUIDGenerator)
            .generateUUID()
            .toString()
    );
    // I can't tell whether generateUUID is guaranteed to produce a unique ID, or just a random ID.
    // so I add this loop to regenerate it in the extremely unlikely (or potentially impossible)
    // event that the UUID is already registered as a CID.
    while (registrar.isCIDRegistered(uuid)) {
        uuid = Components.ID(
            Cc["@mozilla.org/uuid-generator;1"]
                .getService(Ci.nsIUUIDGenerator)
                .generateUUID()
                .toString()
        );
    }
    return uuid;
}

function VintageAboutConfig() {}

let urlString = findAboutConfig();

VintageAboutConfig.prototype = {
    get uri() {
        if (!urlString) return null;
        return this._uri || (this._uri = Services.io.newURI(urlString));
    },
    newChannel: function (_uri, loadInfo) {
        const ch = Services.io.newChannelFromURIWithLoadInfo(this.uri, loadInfo);
        ch.owner = Services.scriptSecurityManager.getSystemPrincipal();
        return ch;
    },
    getURIFlags: function (_uri) {
        return Ci.nsIAboutModule.ALLOW_SCRIPT | Ci.nsIAboutModule.IS_SECURE_CHROME_UI;
    },
    getChromeURI: function (_uri) {
        return this.uri;
    },
    QueryInterface: ChromeUtils.generateQI(["nsIAboutModule"]),
};

var AboutModuleFactory = {
    createInstance(aOuter, aIID) {
        if (aOuter) {
            throw Components.Exception("", Cr.NS_ERROR_NO_AGGREGATION);
        }
        return new VintageAboutConfig().QueryInterface(aIID);
    },
    QueryInterface: ChromeUtils.generateQI(["nsIFactory"]),
};

if (urlString)
    registrar.registerFactory(
        generateFreeCID(),
        `about:${config.address}`,
        `@mozilla.org/network/protocol/about;1?what=${config.address}`,
        AboutModuleFactory
    );

let EXPORTED_SYMBOLS = [];