Checks whether dead Imgur links and images are archived and replaces them.
// ==UserScript==
// @name Imgur Archivist
// @namespace https://reddit.com/u/VladVV/
// @version 0.12
// @description Checks whether dead Imgur links and images are archived and replaces them.
// @author /u/VladVV
// @match *://*/*
// @icon https://www.google.com/s2/favicons?sz=64&domain=archive.org
// @grant none
// @license EUPL v1.2
// ==/UserScript==
(function () {
'use strict';
// Configuration options for the script:
const scriptConfig = {
DOMElements: {
// Any DOM element can be added in the format 'tagName' : 'attribute'
// The attribute will be treated as a URL and replaced with archived URLs
'A' : 'href',
'IMG' : 'src'
},
archiveIcon: '', //TODO: implement little icon to display inside archived elements
linkTooltips: {
// Tooltips when hovering over links. Set to a blank string ("") for nothing.
available: "Archived image available. (Imgur link is dead)",
unavailable: "No archived image available. (Imgur link is dead)"
},
changeLinkStyleOnHover: true, // Archived links will become green/red; set to false to disable
};
// A dictionary to store the dead Imgur URLs and their archived versions
var imgurArchive = {};
// A function to check if an Imgur URL is dead or alive
function checkImgurURL(url) {
// Force HTTPS to prevent cross-domain request issues
url = url.replace('http://','https://');
if (url in imgurArchive) return; //Abort if url has already been checked
var xhr = new XMLHttpRequest();
xhr.open('HEAD', url);
xhr.onreadystatechange = function () {
if (this.readyState === this.DONE) {
if (this.responseURL.indexOf('removed.png') !== -1 || this.status === 404) {
// Imgur image is removed or deleted
// Setup a GET request to the archive.org API
var archiveUrl = 'https://archive.org/wayback/available?url=' + url;
var archiveXhr = new XMLHttpRequest();
archiveXhr.open('GET', archiveUrl);
archiveXhr.onreadystatechange = function () {
if (this.readyState === this.DONE) {
var response = JSON.parse(this.responseText);
if (response.archived_snapshots.closest) {
// Archived image found
// Add the dead link and the archived link to the dictionary
imgurArchive[url] = response.archived_snapshots.closest.url;
} else {
// The removed image is not archived :(
imgurArchive[url] = false;
}
}
};
archiveXhr.send();
} else {
// Imgur image is live; our services aren't needed.
imgurArchive[url] = true;
}
}
};
xhr.send();
}
const archive_org_re = /^(?:https?:\/\/)?(?:web\.archive\.org\/web\/\d+\/)/
// A function to replace an Imgur link with its archived version if it exists in the dictionary
function replaceImgurLink(link) {
var url = link.href.replace(archive_org_re, '');
if (url in imgurArchive) {
if (imgurArchive[url] !== true && imgurArchive[url] !== false) {
// Set archive link if not already set
if (url in imgurArchive) link.setAttribute('href', imgurArchive[url]);
if (scriptConfig.changeLinkStyleOnHover) {
// Save old element attributes to be restored
let old_style = link.style; let old_title = link.title;
// Set temporary element attributes
link.style.color = 'green';
link.style.outline = 'thin dotted green';
link.title = scriptConfig.linkTooltips.available;
// Add event listener to restore old element attributes
link.addEventListener('mouseleave', function () {
link.style = old_style; link.title = old_title;
}, { once: true });
}
} else if (imgurArchive[url] === false && scriptConfig.changeLinkStyleOnHover) {
// Save old element attributes to be restored
let old_style = link.style; let old_title = link.title;
// Set temporary element attributes
link.style.color = 'red';
link.style.outline = 'thin dotted red';
link.title = scriptConfig.linkTooltips.unavailable;
// Add event listener to restore old element attributes
link.addEventListener('mouseleave', function () {
link.style = old_style; link.title = old_title;
}, { once: true });
}
}
}
// A list of elements that have already been processed (for dynamic content loading)
var processed_elements = {};
function updateURLs() {
// Get all the relevant elements in the document
var elements = {};
for (let el in scriptConfig.DOMElements) {
elements[el] = Array.from(document.getElementsByTagName(el));
}
//var links = Array.from(document.getElementsByTagName('a'));
// Filter out link tags that have already been processed
if (processed_elements !== {}) {
for (let el in elements) {
for (let i = 0; i < elements[el].length; i++) {
if (elements[el][i] in processed_elements) {
elements[el].splice(i, 1);
} else {
if (!processed_elements[el]) processed_elements[el] = [];
processed_elements[el].push(elements[el][i]);
}
}
}
} else {
processed_elements = elements;
}
// Loop through the elements and check if they are associated with Imgur links
for (let el in elements) {
for (let i = 0; i < elements[el].length; i++) {
let elementURL = elements[el][i][scriptConfig.DOMElements[el]];
if (elementURL.indexOf('imgur') !== -1 && elementURL.indexOf('archive.org') === -1) {
checkImgurURL(elementURL);
if (elementURL in imgurArchive) {
elements[el][i].setAttribute(scriptConfig.DOMElements[el], imgurArchive[elementURL]);
}
}
}
}
}
updateURLs();
// Create an observer instance to respond to new content loaded dynamically by the page
var observer = new MutationObserver (function (mutations) {
mutations.forEach (function (mutation) {
if (mutation.type === "childList") {
mutation.addedNodes.forEach (function (node) {
var elements = {};
if (node.tagName in scriptConfig.DOMElements) {
elements[node.tagName] = [node];
} else if (node.childNodes && String(node) !== '[object Text]') {
for (let el in scriptConfig.DOMElements) {
elements[el] = node.querySelectorAll(el);
}
} else return;
for (let el in elements) {
for (let i = 0; i < elements[el].length; i++) {
let elementURL = elements[el][i][scriptConfig.DOMElements[el]].replace('http://','https://');
if (elementURL.indexOf('imgur') !== -1 && elementURL.indexOf('archive.org') === -1) {
checkImgurURL(elementURL);
if (elementURL in imgurArchive) {
elements[el][i].setAttribute(scriptConfig.DOMElements[el], imgurArchive[elementURL]);
}
if (!processed_elements[el]) processed_elements[el] = [];
processed_elements[el].push(elements[el][i]);
}
}
}
});
}
});
});
observer.observe(document.documentElement || document.body, {childList: true, subtree: true});
// Add an event listener to the whole document that waits for hovers on links
document.addEventListener('mouseover', function (event) {
// Get the target element of the hover event
var target = event.target;
//Traverse the DOM tree until we find a link (or not)
while (target && target.tagName !== 'A') {
target = target.parentNode;
}
// If a link is found, replace it with its archived version if possible
if (target) {
replaceImgurLink(target);
}
});
})();