Redirect specific sites by replacing part of the URL.
// ==UserScript==
// @name URL Replacer/Redirector
// @namespace https://github.com/theborg3of5/Userscripts/
// @version 2.0
// @description Redirect specific sites by replacing part of the URL.
// @author Gavin Borg
// @require https://openuserjs.org/src/libs/sizzle/GM_config.js
// @match https://greasyfork.org/en/scripts/403100-url-replacer-redirector
// @grant GM_registerMenuCommand
// @grant GM_getValue
// @grant GM_setValue
// @grant GM_deleteValue
// @grant GM.getValue
// @grant GM.setValue
// ==/UserScript==
// Grant GM_*value for legacy Greasemonkey, GM.*value for Greasemonkey 4+
// Settings conversion should be removed after a while, including:
// - convertOldStyleSettings()
// - Grant for GM_deleteValue
// Our configuration instance - this loads/saves settings and handles the config popup.
const Config = new GM_config();
(async function ()
{
'use strict';
// Find the site that we matched
const startURL = window.location.href;
const currentSite = getUserSiteForURL(startURL);
// Add a menu item to the menu to launch the config
GM_registerMenuCommand('Configure redirect settings', () => Config.open());
// Set up and load config
let configSettings = buildConfigSettings(currentSite);
await initConfigAsync(configSettings); // await because we need to read from the resulting (async-loaded) values
// Convert old-style settings if we find them.
await convertOldStyleSettings(configSettings);
// Get replacement settings for the current URL
const replaceSettings = getSettingsForSite(currentSite);
if (!replaceSettings)
{
return;
}
// Build new URL
const newURL = transformURL(startURL, replaceSettings);
// Redirect to the new URL
if (startURL === newURL)
{
logToConsole("Current URL is same as redirection target: " + newURL);
return
}
window.location.replace(newURL);
})();
// Get the site (entry from user includes/matches) that matches the current URL.
function getUserSiteForURL(startURL)
{
for (const site of getUserSites())
{
// Use a RegExp so we check case-insensitively
let siteRegex = "";
if (site.startsWith("/"))
{
siteRegex = new RegExp(site.slice(1, -1), "i"); // If the site starts with a /, treat it as a regex (but remove the leading/trailing /)
}
else
{
siteRegex = new RegExp(site.replace(/\*/g, "[^ ]*"), "i"); // Otherwise replace * wildcards with regex-style [^ ]* wildcards
}
if (siteRegex.test(startURL)) {
return site; // First match always wins
}
}
}
// We support both includes and matches, but only the user-overridden ones of each.
function getUserSites()
{
return GM_info.script.options.override.use_matches.concat(GM_info.script.options.override.use_includes);
}
// Perform the replacements specified by the given settings.
function transformURL(startURL, siteSettings)
{
const { prefix, suffix, targetStrings, replacementStrings } = siteSettings;
// Transform the URL
let newURL = startURL;
for (let i = 0; i < targetStrings.length; i++)
{
let toReplace = prefix + targetStrings[i] + suffix;
const replaceWith = prefix + replacementStrings[i] + suffix;
// Use a RegEx to allow case-insensitive matching
toReplace = new RegExp(escapeRegex(toReplace), "i"); // Escape any regex characters - we don't support actual regex matching.
newURL = newURL.replace(toReplace, replaceWith);
}
return newURL;
}
// From https://stackoverflow.com/questions/3561493/is-there-a-regexp-escape-function-in-javascript/3561711#3561711
function escapeRegex(string)
{
return string.replace(/[-[\]{}()*+!<=:?.\/\\^$|#\s,]/g, '\\$&');
}
// Log a message to the console with a prefix so we know it's from this script.
function logToConsole(message)
{
console.log("URL Replacer/Redirector: " + message);
}
//#region Config handling
// Build the settings object for GM_config.init()
function buildConfigSettings(currentSite)
{
// Build fields for each site
const fields = buildSiteFields(currentSite);
const styles = `
/* Float the target strings fields to the left so that they can line up with their corresponding replacements */
div[id*=${fieldTargetStrings("")}] {
float: left;
}
/* We use one section sub-header on the current site to call it out. We're overriding the
default settings from the framework (which include the ID), so !important is needed for
most of these properties. */
.section_desc {
float: right !important;
background: #00FF00 !important;
color: black !important;
width: fit-content !important;
font-weight: bold !important;
padding: 4px !important;
margin: 0px auto !important;
border-top: none !important;
border-radius: 0px 0px 10px 10px !important;
}";
`.replaceAll("\n", ""); // This format is nicer to read but the newlines cause issues in the config framework, so remove them
return {
id: "URLReplacerRedirectorConfig",
title: "URL Replacer/Redirector Config",
fields: fields,
css: styles,
};
}
// Build the specific fields in the config
function buildSiteFields(currentSite)
{
let fields = {};
for (const site of getUserSites())
{
// Section headers are the site URL as the user entered them
const sectionName = [site];
if (currentSite === site)
{
sectionName.push("This site"); // If this is the matched site, add a subheader to call it out
}
fields[fieldPrefix(site)] = {
section: sectionName, // Section definition just goes on the first field inside
type: "text",
label: "Prefix",
labelPos: "left",
size: 75,
title: "This string (if set) must appear directly before the target string in the URL.",
}
fields[fieldSuffix(site)] = {
type: "text",
label: "Suffix",
labelPos: "left",
size: 75,
title: "This string (if set) must appear directly after the target string in the URL.",
}
fields[fieldTargetStrings(site)] = {
type: "textarea",
label: "Targets",
labelPos: "above",
title: "Enter one target per line. Each target will be replaced by its corresponding replacement.",
}
fields[fieldReplacementStrings(site)] = {
type: "textarea",
label: "Replacements",
labelPos: "above",
title: "Enter one replacement per line. Each replacement with replace its corresponding target.",
}
fields[fieldClearSite(site)] = {
type: "button",
label: "Clear redirects for this site",
title: "Clear all fields for this site, removing all redirection.",
save: false, // Don't save this field, it's just a button
click: function (siteToClear)
{
return () => {
Config.set(fieldPrefix(siteToClear), "");
Config.set(fieldSuffix(siteToClear), "");
Config.set(fieldTargetStrings(siteToClear), "");
Config.set(fieldReplacementStrings(siteToClear), "");
}
}(site), // Immediately invoke this wrapper with the current site so the inner function can capture it
}
}
return fields;
}
// This is just a Promise wrapper for GM_config.init that allows us to await initialization.
async function initConfigAsync(settings)
{
return new Promise((resolve) =>
{
// Have the init event (which should fire once config is done loading) resolve the promise
settings["events"] = {init: resolve};
Config.init(settings);
});
}
// Get the settings for the given site.
function getSettingsForSite(site)
{
if (!site)
{
console.log("No matching site found for URL");
return null;
}
// Retrieve and return the settings
return {
prefix: Config.get(fieldPrefix(site)),
suffix: Config.get(fieldSuffix(site)),
targetStrings: Config.get(fieldTargetStrings(site)).split("\n"),
replacementStrings: Config.get(fieldReplacementStrings(site)).split("\n"),
}
}
//#region Field name "constants" based on their corresponding sites
// These are also the keys used with [GM_]Config.get/set.
function fieldPrefix(site)
{
return "Prefix_" + site;
}
function fieldSuffix(site)
{
return "Suffix_" + site;
}
function fieldTargetStrings(site)
{
return "TargetString_" + site;
}
function fieldReplacementStrings(site)
{
return "ReplacementString_" + site;
}
function fieldClearSite(site)
{
return "ClearSite_" + site;
}
//#endregion Field name "constants" based on their corresponding sites
//#endregion Config handling
// Convert settings from the old style (simple GM_setValue/GM_getValue storage, 1 config for all
// sites) to the new style (GM_config, one set of settings per site).
async function convertOldStyleSettings(gmConfigSettings)
{
// Check the only really required setting (for the script to do anything)
const replaceAry = GM_getValue("replaceTheseStrings");
if (!replaceAry)
{
return; // No old settings to convert, done.
}
logToConsole("Old-style settings found");
// Safety check: if we ALSO have new-style settings, leave it alone.
if (GM_getValue("URLReplacerRedirectorConfig"))
{
logToConsole("New-style settings already exist, not converting old settings.");
return;
}
const replacePrefix = GM_getValue("replacePrefix");
const replaceSuffix = GM_getValue("replaceSuffix");
// Old style: 1 config for ALL sites
// New style: 1 config PER site
// So, the conversion is just to copy the config onto each site.
logToConsole("Starting settings conversion...");
for (const site of getUserSites())
{
// Split replaceAry into targets (keys) and replacements (values)
let targetsAry = [];
let replacementsAry = [];
for (const target in replaceAry)
{
targetsAry.push(target);
replacementsAry.push(replaceAry[target]);
}
Config.set(fieldPrefix(site), replacePrefix);
Config.set(fieldSuffix(site), replaceSuffix);
Config.set(fieldTargetStrings(site), targetsAry.join("\n"));
Config.set(fieldReplacementStrings(site), replacementsAry.join("\n"));
}
// Save new settings
Config.save();
logToConsole("New-style settings saved.");
// Remove the old-style settings so we don't do this again each time.
GM_deleteValue("replaceTheseStrings");
GM_deleteValue("replacePrefix");
GM_deleteValue("replaceSuffix");
logToConsole("Old-style settings removed.");
logToConsole("Conversion complete.");
}