Add international links to Amazon product pages
// ==UserScript==
// @name Amazon International Links
// @description Add international links to Amazon product pages
// @author chocolateboy
// @copyright chocolateboy
// @version 4.1.1
// @namespace https://github.com/chocolateboy/userscripts
// @license GPL
// @include https://smile.amazon.tld/*
// @include https://www.amazon.tld/*
// @require https://code.jquery.com/jquery-3.7.1.slim.min.js
// @require https://cdn.jsdelivr.net/gh/sizzlemctwizzle/GM_config@43fd0fe4de1166f343883511e53546e87840aeaf/gm_config.js
// @grant GM_registerMenuCommand
// @grant GM_getValue
// @grant GM_setValue
// ==/UserScript==
// XXX GM_getValue and GM_setValue are used by GM_config
/*
*
* further reading:
*
* https://helpful.knobs-dials.com/index.php/Amazon_notes#Links
*/
/*********************** Constants ********************************/
/*
* a map from the Amazon TLD to the corresponding two-letter country code
*
* XXX technically, UK should be GB: https://en.wikipedia.org/wiki/ISO_3166-1_alpha-2
*/
const SITES = {
'com.au': 'AU', // Australia
'com.be': 'BE', // Belgium
'com.br': 'BR', // Brazil
'ca': 'CA', // Canada
'cn': 'CN', // China
'fr': 'FR', // France
'de': 'DE', // Germany
'in': 'IN', // India
'ie': 'IE', // Ireland
'it': 'IT', // Italy
'co.jp': 'JP', // Japan
'com.mx': 'MX', // Mexico
'nl': 'NL', // Netherlands
'es': 'ES', // Spain
'se': 'SE', // Sweden
'com.tr': 'TR', // Turkey
'ae': 'AE', // UAE
'co.uk': 'UK', // UK
'com': 'US', // US
}
/*
* Amazon TLDs which support the "smile.amazon" subdomain
*/
const SMILE = new Set(['com', 'co.uk', 'de'])
/*********************** Functions and Classes ********************************/
/*
* A class which encapsulates the logic for creating and updating cross-site links
*/
class Linker {
/*
* get the unique identifier (ASIN - Amazon Standard Identification Number)
* for this product, or return a falsey value if it's not found
*/
static getASIN () {
const $asin = $('input#ASIN, input[name="ASIN"], input[name="ASIN.0"]')
let asin
if ($asin.length) {
asin = $asin.val()
} else { // if there's a canonical link, try to retrieve the ASIN from its URI
// <link rel="canonical" href="https://www.amazon.com/Follows-Movie-Poster-18-28/dp/B01BKUBARA" />
const canonical = $('link[rel="canonical"][href]').attr('href')
let match
if (canonical && (match = canonical.match('/dp/(\\w+)$'))) {
asin = match[1]
}
}
return asin
}
constructor (asin) {
// the unique Amazon identifier for this product
this.asin = asin
// the navbar to add the cross-site links to
this.navbar = $('#nav-xshop .nav-ul')
// an array of our added elements - jQuery wrappers of child elements of
// the cross-site links navbar
//
// we keep a reference to these elements so we can easily remove them
// from the DOM (and replace them with new elements) whenever the
// country selection changes
this.links = []
// extract and store 1) the subdomain (e.g. "www.amazon") and 2) the TLD
// (e.g. "co.uk") of the current site
const parts = location.hostname.split('.')
// 1) the subdomain (part before the TLD) of the current site, e.g.
// "www.amazon" or "smile.amazon"
this.subdomain = parts.slice(0, 2).join('.')
// 2) the TLD of the current site, e.g. "co.uk" or "com"
this.tld = parts.slice(2).join('.')
}
/*
* add a child element to the internal `links` array
*/
addLink (tld, country) {
const attrs = {
class: 'nav-a',
title: `amazon.${tld}`
}
// XXX we can't always preserve the "smile.amazon" subdomain as it's not
// available for most Amazon TLDs
const subdomain = SMILE.has(tld) ? this.subdomain : 'www.amazon'
let tag
if (tld === this.tld) {
tag = 'strong'
} else {
tag = 'a'
attrs.href = `//${subdomain}.${tld}/dp/${this.asin}`
}
// serialize the attributes, e.g. { title: 'amazon.com' } -> `title="amazon.com"`
const $attrs = Object.entries(attrs)
.map(([key, value]) => `${key}=${JSON.stringify(value)}`)
.join(' ')
const link =
`<li class="nav-li">
<div class="nav-div">
<${tag} ${$attrs}>${country}</${tag}>
</div>
</li>`
this.links.push($(link))
}
/*
* populate the array of links and display them by prepending them to the
* body of the cross-site navigation bar
*/
addLinks () {
// create the subset of the TLD -> country-code map (SITES)
// corresponding to the enabled sites
const sites = Object.entries(SITES)
.filter(([tld]) => GM_config.get(tld))
.reduce((obj, [key, val]) => { return obj[key] = val, obj }, {})
if ($.isEmptyObject(sites)) {
return
}
// sort the sites by the country code (e.g. AU) rather than the TLD
// (e.g. com.au)
// const tlds = sortBy(Object.keys(sites), tld => sites[tld])
const tlds = Object.keys(sites).sort((a, b) => sites[a].localeCompare(sites[b]))
// populate the `links` array with jQuery wrappers for each link
// element (e.g. <li>...</li>)
for (const tld of tlds) {
this.addLink(tld, sites[tld])
}
// prepend the cross-site links to the body of the navbar
this.navbar.prepend(...this.links)
}
/*
* build the underlying data model used by the GM_config utility
*/
initializeConfig () {
const checkboxes = {}
// sort by country code
for (const tld of Object.keys(SITES).sort((a, b) => SITES[a].localeCompare(SITES[b]))) {
const country = SITES[tld]
checkboxes[tld] = {
type: 'checkbox',
label: country,
title: `amazon.${tld}`,
default: (country === 'UK' || country === 'US')
}
}
// re-render the links when the settings are updated
const save = () => {
this.removeLinks()
this.addLinks()
GM_config.close()
}
const callbacks = { save }
GM_config.init('Amazon International Links Settings', checkboxes, callbacks)
}
/*
* remove all added links from the DOM and clear the array referencing them
*/
removeLinks () {
const { links } = this
for (const $link of links) {
$link.remove() // remove from the DOM...
}
links.length = 0 // ...and empty the array
}
}
/*********************** Main ********************************/
const run = () => {
const asin = Linker.getASIN()
if (!asin) {
return
}
const showConfig = () => GM_config.open() // display the settings manager
const linker = new Linker(asin)
linker.initializeConfig()
linker.addLinks()
GM_registerMenuCommand('Configure Amazon International Links', showConfig)
}
run()