117 lines
4.1 KiB
JavaScript
117 lines
4.1 KiB
JavaScript
const swap_event = new Event("swap");
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let caches = {};
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async function cached_fetch(url) {
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let cached = caches[url];
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console.log("cache: " + cached);
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const res = cached === undefined ? await fetch(url) : await fetch(url, {
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headers: {
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"If-Modified-Since": cached.last_modified
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}
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});
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if (res.status === 304 && cached !== undefined) {
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return cached.content;
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}
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if (res.status !== 200) return;
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if (!res.headers.get("content-type").startsWith("text/html")) return;
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const text = await res.text();
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if (res.headers.get("last-modified")) {
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caches[url] = {
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content: text,
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last_modified: res.headers.get("last-modified")
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}
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}
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return text;
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}
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async function swap(url, stateful) {
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if (typeof url !== 'string') return;
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const segments = window.location.href.split("/");
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if (url.startsWith(window.location.origin) && segments[segments.length - 1].includes("#")) {
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window.location.href = url;
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return;
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}
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if (stateful && window.location.href.endsWith(url)) return;
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const text = await cached_fetch(url);
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const content = new DOMParser().parseFromString(text, "text/html");
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const stylesheets = [...content.querySelectorAll("link[rel='stylesheet']")];
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// swap title
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document.title = content.title;
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// swap body html
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document.body.innerHTML = content.body.innerHTML;
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// swap stylesheets
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const old_sheets = document.head.querySelectorAll("link[rel='stylesheet']");
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stylesheets.forEach(stylesheet => {
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let exists = false;
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old_sheets.forEach(old_sheet => {
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if (old_sheet.href === stylesheet.href) exists = true;
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});
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if (!exists) document.head.appendChild(stylesheet);
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});
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old_sheets.forEach(old_sheet => {
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let exists = false;
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stylesheets.forEach(stylesheet => {
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if (stylesheet.href === old_sheet.href) exists = true;
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});
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if (!exists) old_sheet.remove();
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});
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// push history
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if (stateful) history.pushState(url, "", url);
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bind(document.body);
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}
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function bind(content) {
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if (typeof content !== 'object' || content.nodeType !== Node.ELEMENT_NODE) return;
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content.querySelectorAll("[swap-url]").forEach(element => {
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const href = element.attributes.getNamedItem('swap-url').value;
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element.addEventListener("click", event => {
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event.preventDefault();
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swap(href, true);
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});
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[...element.querySelectorAll("a[href], [swap-url]")].forEach(element => {
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if (element.href) {
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if (!element.href.endsWith(href)) return;
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element.attributes.removeNamedItem("href");
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}
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const swap_url = element.attributes.getNamedItem("swap-url");
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if (swap_url) {
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if (!swap_url.endsWith(href)) return;
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element.attributes.removeNamedItem("swap-url");
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}
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});
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});
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content.querySelectorAll("a[href]:not([swap-url])").forEach(element => {
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if (element.href.includes("#")) return;
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if (!element.href.startsWith(window.location.origin)) return;
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const href = element.href.substring(window.location.origin.length);
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if (href.includes(".")) return;
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element.addEventListener("click", event => {
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event.preventDefault();
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swap(element.href, true);
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});
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});
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document.dispatchEvent(swap_event);
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}
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window.addEventListener("popstate", event => {
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swap(event.state, false);
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});
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bind(document.body);
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