Shows the official website link directly on AlternativeTo software pages
// ==UserScript==
// @name AlternativeTo Homepage Up Top
// @namespace https://greasyfork.org/en/users/1337417-mevanlc
// @version 1.0
// @description Shows the official website link directly on AlternativeTo software pages
// @author You
// @match https://alternativeto.net/software/*
// @match http://alternativeto.net/software/*
// @license MIT
// @grant none
// ==/UserScript==
(function() {
'use strict';
const DEBUG = false;
const SCRIPT_NAME =
(typeof GM_info !== 'undefined' && GM_info.script && GM_info.script.name)
? GM_info.script.name
: 'AlternativeTo Homepage Injector';
function logd(...args) {
if (!DEBUG) return;
console.log(`${SCRIPT_NAME}:`, ...args);
}
const state = {
currentProductId: null,
container: null,
observer: null,
navigationTimer: null,
navigationListenersAttached: false,
};
logd('Script booted', { href: window.location.href });
setupNavigationListeners();
handleNavigation();
function handleNavigation() {
const pathname = window.location.pathname;
const pageInfo = extractPageInfo(pathname);
const productId = pageInfo ? pageInfo.productId : null;
logd('Handling navigation', {
pathname,
productId,
currentProductId: state.currentProductId,
isAboutPage: pageInfo ? pageInfo.isAboutPage : false,
});
if (!pageInfo) {
logd('Current page does not match software detail; performing cleanup');
cleanupContainer();
state.currentProductId = null;
return;
}
if (state.currentProductId === productId && state.container) {
logd('Product unchanged; ensuring container presence');
if (pageInfo.isAboutPage) {
populateHomepageFromDocument(document, productId, state.container);
}
insertHomepageContainer(state.container);
return;
}
logd('Product changed; rebuilding container and data', {
previous: state.currentProductId,
next: productId,
});
cleanupContainer();
state.currentProductId = productId;
state.container = createHomepageContainer(productId);
insertHomepageContainer(state.container);
state.observer = setupMutationObserver(state.container);
if (pageInfo.isAboutPage) {
populateHomepageFromDocument(document, productId, state.container);
} else {
fetchHomepage(productId, state.container);
}
}
function extractPageInfo(pathname) {
const aboutMatch = pathname.match(/^\/software\/([^\/]+)\/about\/?$/);
if (aboutMatch) {
return {
productId: aboutMatch[1],
isAboutPage: true,
};
}
const productMatch = pathname.match(/^\/software\/([^\/]+)\/?$/);
if (productMatch) {
return {
productId: productMatch[1],
isAboutPage: false,
};
}
return null;
}
function cleanupContainer() {
if (state.observer) {
state.observer.disconnect();
state.observer = null;
}
if (state.container) {
if (state.container.isConnected) {
state.container.remove();
}
state.container = null;
}
}
function fetchHomepage(productId, homepageContainer) {
const aboutUrl = `https://alternativeto.net/software/${productId}/about/`;
logd('Initiating fetch to about page', { aboutUrl, productId });
fetch(aboutUrl)
.then(response => {
logd('Received about page response', { status: response.status, ok: response.ok, productId });
if (!response.ok) {
throw new Error(`HTTP error! status: ${response.status}`);
}
return response.text();
})
.then(html => {
if (state.container !== homepageContainer || state.currentProductId !== productId) {
logd('Ignoring fetch result for stale product', {
productId,
currentProductId: state.currentProductId,
});
return;
}
logd('Parsing about page HTML', { productId });
const parser = new DOMParser();
const doc = parser.parseFromString(html, 'text/html');
applyHomepageToContainer({
homepageContainer,
homepageUrl: resolveHomepageUrlFromDocument(doc, productId),
productId,
});
})
.catch(error => {
if (state.container !== homepageContainer || state.currentProductId !== productId) {
logd('Fetch rejected for stale product', { error, productId });
return;
}
logd('Error fetching or processing about page', { error, productId });
homepageContainer.innerHTML = '<span style="color: #ff6b6b;">Error loading website info</span>';
console.error('AlternativeTo Homepage Injector error:', error);
});
}
function populateHomepageFromDocument(doc, productId, homepageContainer) {
logd('Populating homepage from current document', { productId });
applyHomepageToContainer({
homepageContainer,
homepageUrl: resolveHomepageUrlFromDocument(doc, productId),
productId,
});
}
function resolveHomepageUrlFromDocument(doc, productId) {
logd('Executing strategy 1: links with nearby "official" text', { productId });
const allLinks = doc.querySelectorAll('a[href^="http"]:not([href*="alternativeto"])');
for (const link of allLinks) {
const prevText = (link.previousSibling && link.previousSibling.textContent) || '';
const parentText = (link.parentElement && link.parentElement.textContent) || '';
if (prevText.toLowerCase().includes('official') || parentText.toLowerCase().includes('official website')) {
logd('Strategy 1 matched candidate link', { homepageUrl: link.href, productId });
return link.href;
}
}
logd('Strategy 1 failed, trying strategy 2: containers mentioning Website/Homepage', { productId });
const possibleContainers = doc.querySelectorAll('div, p, li, td');
for (const elem of possibleContainers) {
const text = elem.textContent || '';
if (text.includes('Website') || text.includes('Homepage')) {
const link = elem.querySelector('a[href^="http"]:not([href*="alternativeto"])');
if (link) {
logd('Strategy 2 matched candidate link', { homepageUrl: link.href, productId });
return link.href;
}
}
}
logd('Strategy 2 failed, trying strategy 3: first non-social external link', { productId });
for (const link of allLinks) {
const href = link.href;
const text = link.textContent || '';
if (!href.includes('facebook') &&
!href.includes('twitter') &&
!href.includes('youtube') &&
!href.includes('github.com/sponsors') &&
!href.includes('patreon') &&
!href.includes('instagram') &&
!href.includes('linkedin') &&
text.length > 0) {
logd('Strategy 3 matched candidate link', { homepageUrl: href, productId });
return href;
}
}
logd('All strategies failed to locate homepage URL', { productId });
return null;
}
function applyHomepageToContainer({ homepageContainer, homepageUrl, productId }) {
if (state.container !== homepageContainer || state.currentProductId !== productId) {
logd('Container changed during processing; abandoning update', {
productId,
currentProductId: state.currentProductId,
});
return;
}
if (!homepageUrl) {
homepageContainer.innerHTML = '<span style="color: #999;">Official website not available</span>';
return;
}
logd('Homepage URL determined', { homepageUrl, productId });
try {
const url = new URL(homepageUrl);
const cleanUrl = url.origin + url.pathname;
logd('Normalized homepage URL', { cleanUrl, productId });
homepageContainer.innerHTML = `
<span style="font-weight: bold;">Official Website:</span>
<a href="${homepageUrl}" target="_blank" rel="noopener noreferrer"
style="color: #0099ff; text-decoration: none; font-weight: 500;">
${cleanUrl}
<span style="font-size: 12px; vertical-align: super;">↗</span>
</a>
`;
} catch (e) {
logd('Failed to normalize URL, falling back to raw href', { error: e, productId });
homepageContainer.innerHTML = `
<span style="font-weight: bold;">Official Website:</span>
<a href="${homepageUrl}" target="_blank" rel="noopener noreferrer"
style="color: #0099ff; text-decoration: none; font-weight: 500;">
${homepageUrl}
<span style="font-size: 12px; vertical-align: super;">↗</span>
</a>
`;
}
}
function createHomepageContainer(productId) {
logd('Creating homepage container element', { productId });
const el = document.createElement('div');
el.id = 'homepage-injector';
el.dataset.productId = productId;
el.style.cssText = `
background: #f0f8ff;
border: 2px solid #0099ff;
border-radius: 8px;
padding: 12px;
margin: 15px 0;
display: flex;
align-items: center;
gap: 10px;
font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
`;
el.innerHTML = '<span style="font-weight: bold;">Official Website:</span> <span style="color: #666;">Loading...</span>';
return el;
}
function insertHomepageContainer(homepageContainer) {
if (!homepageContainer) {
return;
}
if (homepageContainer.isConnected) {
logd('Homepage container already connected; skipping insert', { productId: homepageContainer.dataset.productId });
return;
}
const existing = document.getElementById(homepageContainer.id);
if (existing && existing !== homepageContainer) {
logd('Replacing foreign element using homepage container id');
existing.replaceWith(homepageContainer);
return;
}
const titleElement = document.querySelector('h1');
if (titleElement && titleElement.parentElement) {
logd('Injecting container after title element');
titleElement.parentElement.insertAdjacentElement('afterend', homepageContainer);
return;
}
const mainContent = document.querySelector('main') || document.querySelector('[role="main"]') || document.body;
if (mainContent) {
logd('Title element not found; inserting container at beginning of main content');
mainContent.insertAdjacentElement('afterbegin', homepageContainer);
} else if (state.container === homepageContainer) {
logd('No insertion target found; retrying shortly');
setTimeout(() => {
if (state.container === homepageContainer) {
insertHomepageContainer(homepageContainer);
}
}, 100);
}
}
function setupMutationObserver(homepageContainer) {
logd('Setting up mutation observer to protect container', { productId: homepageContainer.dataset.productId });
const observer = new MutationObserver(() => {
const pageInfo = extractPageInfo(window.location.pathname);
const activeProductId = pageInfo ? pageInfo.productId : null;
if (activeProductId !== state.currentProductId) {
logd('Observer noticed product id change; scheduling navigation handling', {
activeProductId,
currentProductId: state.currentProductId,
});
scheduleNavigationCheck('observer-product-change');
return;
}
const current = document.getElementById(homepageContainer.id);
if (current === homepageContainer) {
return;
}
if (current && current !== homepageContainer) {
logd('Observer detected foreign element with homepage id; replacing');
current.replaceWith(homepageContainer);
return;
}
if (!homepageContainer.isConnected) {
logd('Observer detected missing container; re-inserting');
insertHomepageContainer(homepageContainer);
}
});
(function startObserving() {
const target = document.body || document.documentElement;
if (!target) {
logd('Observer target unavailable; retrying in 100ms');
setTimeout(() => {
if (state.container === homepageContainer) {
startObserving();
}
}, 100);
return;
}
observer.observe(target, { childList: true, subtree: true });
logd('Mutation observer attached');
})();
return observer;
}
function scheduleNavigationCheck(reason) {
logd('Scheduling navigation check', {
reason,
existingTimer: Boolean(state.navigationTimer),
});
if (state.navigationTimer) {
clearTimeout(state.navigationTimer);
}
state.navigationTimer = setTimeout(() => {
state.navigationTimer = null;
handleNavigation();
}, 50);
}
function setupNavigationListeners() {
if (state.navigationListenersAttached) {
return;
}
state.navigationListenersAttached = true;
const wrapHistory = method => {
const original = history[method];
if (typeof original !== 'function') {
return;
}
history[method] = function(...args) {
const result = original.apply(this, args);
logd(`Detected ${method} navigation`, { args });
scheduleNavigationCheck(method);
return result;
};
};
wrapHistory('pushState');
wrapHistory('replaceState');
window.addEventListener('popstate', () => scheduleNavigationCheck('popstate'));
window.addEventListener('hashchange', () => scheduleNavigationCheck('hashchange'));
}
})();