Tahinli/forge
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| 1 | // Soft navigation. Same-app links and form posts are fetched and swapped into the page in place, |
| 2 | // so a button press no longer reloads the whole document. Progressive enhancement: without this |
| 3 | // script (or on any failure) the browser's own navigation runs. Forms marked `data-hard` (sign-in, |
| 4 | // sign-out, enrolment, password and account changes) always post natively. |
| 5 | (function () { |
| 6 | 'use strict'; |
| 7 | if (window.__forgeSoft) { return; } |
| 8 | window.__forgeSoft = true; |
| 9 | |
| 10 | var root = document.documentElement; |
| 11 | var latest = 0; // id of the newest request; older responses are dropped |
| 12 | var inFlight = 0; // requests on the wire, drives aria-busy |
| 13 | var pending = new WeakSet(); // forms with a request on the wire: a second submit is ignored |
| 14 | var shown = location.pathname + location.search; |
| 15 | var GET_INIT = { headers: { accept: 'text/html' } }; |
| 16 | |
| 17 | // Files, not pages: static assets, the JSON api, archives, raw and LFS objects and release |
| 18 | // downloads. These always take the browser's own path. |
| 19 | var FILE_PATH = /^\/(assets|api)\/|^\/[^\/]+\/[^\/]+\/(archive|raw|info\/lfs|-\/media|releases\/download)(\/|$)/; |
| 20 | |
| 21 | function busyStart() { |
| 22 | inFlight += 1; |
| 23 | root.setAttribute('aria-busy', 'true'); |
| 24 | } |
| 25 | |
| 26 | function busyEnd() { |
| 27 | inFlight = Math.max(0, inFlight - 1); |
| 28 | if (inFlight === 0) { root.removeAttribute('aria-busy'); } |
| 29 | } |
| 30 | |
| 31 | // The URL to fetch for `href`, or null when the browser should handle it: another origin, a file |
| 32 | // route, or a value that does not parse. |
| 33 | function pageUrl(href) { |
| 34 | var url; |
| 35 | try { url = new URL(href, location.href); } catch (err) { return null; } |
| 36 | if (url.origin !== location.origin || FILE_PATH.test(url.pathname)) { return null; } |
| 37 | return url; |
| 38 | } |
| 39 | |
| 40 | function withoutHash(url) { |
| 41 | var out = new URL(url.href); |
| 42 | out.hash = ''; |
| 43 | return out; |
| 44 | } |
| 45 | |
| 46 | // Field preservation: a dirty or focused field keeps its value, and the caret offsets come along. |
| 47 | function fieldKey(el) { |
| 48 | var form = el.form ? (el.form.getAttribute('action') || '') : ''; |
| 49 | return form + '|' + (el.name || '') + '|' + (el.type || '') + '|' + el.tagName; |
| 50 | } |
| 51 | |
| 52 | function savable(el) { |
| 53 | return el.type !== 'hidden' && el.type !== 'password' && el.type !== 'file'; |
| 54 | } |
| 55 | |
| 56 | function captureFields() { |
| 57 | var active = document.activeElement; |
| 58 | var out = []; |
| 59 | document.querySelectorAll('input, textarea, select').forEach(function (el) { |
| 60 | if (!savable(el)) { return; } |
| 61 | var moved; |
| 62 | if (el.type === 'checkbox' || el.type === 'radio') { |
| 63 | moved = el.checked !== el.defaultChecked; |
| 64 | } else if (el.tagName === 'SELECT') { |
| 65 | var def = -1; |
| 66 | for (var j = 0; j < el.options.length; j++) { |
| 67 | if (el.options[j].defaultSelected) { def = j; break; } |
| 68 | } |
| 69 | if (def < 0) { def = 0; } |
| 70 | moved = el.selectedIndex !== def; |
| 71 | } else { |
| 72 | moved = el.value !== el.defaultValue; |
| 73 | } |
| 74 | var focused = el === active; |
| 75 | if (!moved && !focused) { return; } |
| 76 | var start = -1, end = -1; |
| 77 | try { |
| 78 | if (el.selectionStart != null) { start = el.selectionStart; end = el.selectionEnd; } |
| 79 | } catch (err) { } |
| 80 | out.push({ k: fieldKey(el), v: el.value, c: el.checked, i: el.selectedIndex, f: focused, s: start, e: end }); |
| 81 | }); |
| 82 | return out; |
| 83 | } |
| 84 | |
| 85 | function restoreFields(saved) { |
| 86 | if (!saved || !saved.length) { return; } |
| 87 | var fields = document.querySelectorAll('input, textarea, select'); |
| 88 | saved.forEach(function (was) { |
| 89 | var el = null; |
| 90 | for (var i = 0; i < fields.length; i++) { |
| 91 | if (fieldKey(fields[i]) === was.k) { el = fields[i]; break; } |
| 92 | } |
| 93 | if (!el) { return; } |
| 94 | if (el.type === 'checkbox' || el.type === 'radio') { el.checked = was.c; } |
| 95 | else if (el.tagName === 'SELECT') { el.selectedIndex = was.i; } |
| 96 | else { el.value = was.v; } |
| 97 | if (was.f) { |
| 98 | try { |
| 99 | el.focus({ preventScroll: true }); |
| 100 | if (was.s >= 0 && el.setSelectionRange) { el.setSelectionRange(was.s, was.e); } |
| 101 | } catch (err) { } |
| 102 | } |
| 103 | }); |
| 104 | } |
| 105 | |
| 106 | // Stylesheets in <head> follow the new page: missing ones are added, extra ones removed. Matched by |
| 107 | // href, so main.css and the highlight sheet stay in place when they are the same. |
| 108 | function syncStyles(doc) { |
| 109 | var sheets = 'link[rel="stylesheet"]'; |
| 110 | var wanted = {}; |
| 111 | doc.head.querySelectorAll(sheets).forEach(function (l) { wanted[l.getAttribute('href') || ''] = true; }); |
| 112 | var have = {}; |
| 113 | document.head.querySelectorAll(sheets).forEach(function (l) { have[l.getAttribute('href') || ''] = true; }); |
| 114 | doc.head.querySelectorAll(sheets).forEach(function (l) { |
| 115 | var href = l.getAttribute('href') || ''; |
| 116 | if (!have[href]) { |
| 117 | have[href] = true; |
| 118 | document.head.appendChild(document.importNode(l, true)); |
| 119 | } |
| 120 | }); |
| 121 | document.head.querySelectorAll(sheets).forEach(function (l) { |
| 122 | if (!wanted[l.getAttribute('href') || '']) { l.remove(); } |
| 123 | }); |
| 124 | } |
| 125 | |
| 126 | function adopt(doc, keepFields) { |
| 127 | document.title = doc.title; |
| 128 | ['lang', 'data-theme', 'data-ui'].forEach(function (name) { |
| 129 | if (doc.documentElement.hasAttribute(name)) { root.setAttribute(name, doc.documentElement.getAttribute(name)); } |
| 130 | else { root.removeAttribute(name); } |
| 131 | }); |
| 132 | syncStyles(doc); |
| 133 | var kept = keepFields ? captureFields() : null; |
| 134 | var nodes = Array.prototype.map.call(doc.body.childNodes, function (n) { return document.importNode(n, true); }); |
| 135 | document.body.replaceChildren.apply(document.body, nodes); |
| 136 | // Re-create scripts so they run (a parsed-in script does not). The guard above keeps this file |
| 137 | // from starting twice. |
| 138 | document.body.querySelectorAll('script').forEach(function (old) { |
| 139 | var s = document.createElement('script'); |
| 140 | Array.prototype.forEach.call(old.attributes, function (a) { s.setAttribute(a.name, a.value); }); |
| 141 | s.textContent = old.textContent; |
| 142 | old.replaceWith(s); |
| 143 | }); |
| 144 | if (kept) { restoreFields(kept); } |
| 145 | } |
| 146 | |
| 147 | function focusMain() { |
| 148 | var main = document.querySelector('main'); |
| 149 | if (main && main.focus) { main.focus({ preventScroll: true }); } |
| 150 | } |
| 151 | |
| 152 | // Scrolls to the fragment's element when there is one. Returns false when there is nothing to scroll to. |
| 153 | function placeHash(hash) { |
| 154 | if (!hash || hash.length < 2) { return false; } |
| 155 | var id; |
| 156 | try { id = decodeURIComponent(hash.slice(1)); } catch (err) { id = hash.slice(1); } |
| 157 | var el = document.getElementById(id); |
| 158 | if (!el) { return false; } |
| 159 | el.scrollIntoView(); |
| 160 | return true; |
| 161 | } |
| 162 | |
| 163 | // how: 'nav' (link or GET form: push, top), 'pop' (history: push nothing, restore scroll), |
| 164 | // 'post' (form post: replace, keep scroll), 'query' (in place: replace, keep scroll). |
| 165 | function swap(html, dest, how, keepFields) { |
| 166 | var doc = new DOMParser().parseFromString(html, 'text/html'); |
| 167 | if (!doc.body) { location.assign(dest.href); return; } |
| 168 | var x = window.scrollX, y = window.scrollY; |
| 169 | var saved = history.state; |
| 170 | adopt(doc, keepFields); |
| 171 | if (how === 'nav') { history.pushState(null, '', dest.href); } |
| 172 | else if (how === 'post' || how === 'query') { history.replaceState(null, '', dest.href); } |
| 173 | shown = dest.pathname + dest.search; |
| 174 | if (how === 'nav' || how === 'pop') { focusMain(); } |
| 175 | if (placeHash(dest.hash)) { return; } |
| 176 | if (how === 'post' || how === 'query') { window.scrollTo(x, y); } |
| 177 | else if (how === 'pop') { window.scrollTo(0, saved && typeof saved.y === 'number' ? saved.y : 0); } |
| 178 | else { window.scrollTo(0, 0); } |
| 179 | } |
| 180 | |
| 181 | // The browser takes over where a soft request cannot: a non-HTML answer, or another origin. |
| 182 | // A GET re-requests the page itself. A POST is never sent again (that would repeat the action): |
| 183 | // a redirect is followed as a GET, anything else reloads the current page. |
| 184 | function leave(res, o) { |
| 185 | if (o.post) { |
| 186 | if (res.redirected) { location.assign(res.url.href); } else { location.reload(); } |
| 187 | return; |
| 188 | } |
| 189 | var sameOrigin = res.url.origin === location.origin; |
| 190 | location.assign(sameOrigin && !res.redirected ? o.dest.href : res.url.href); |
| 191 | } |
| 192 | |
| 193 | // One request for a page. `o` carries target (fetched, no hash), dest (shown, with hash), init, |
| 194 | // how, keep (keep fields on a re-render of the same path), post, and the form for a POST or GET form. |
| 195 | function load(o) { |
| 196 | var mark = ++latest; |
| 197 | busyStart(); |
| 198 | fetch(o.target.href, o.init).then(function (r) { |
| 199 | var final = new URL(r.url || o.target.href); |
| 200 | var html = /^\s*text\/html/i.test(r.headers.get('content-type') || ''); |
| 201 | if (final.origin !== location.origin || !html) { |
| 202 | return { leave: true, url: final, redirected: r.redirected }; |
| 203 | } |
| 204 | return r.text().then(function (text) { return { html: text, url: final }; }); |
| 205 | }).then(function (res) { |
| 206 | if (mark !== latest) { return; } |
| 207 | if (res.leave) { leave(res, o); return; } |
| 208 | var dest = new URL(res.url.href); |
| 209 | dest.hash = o.dest.hash; |
| 210 | swap(res.html, dest, o.how, !!o.keep && res.url.pathname === o.target.pathname); |
| 211 | }).catch(function () { |
| 212 | if (mark !== latest) { return; } |
| 213 | if (o.post) { o.form.submit(); } else { location.assign(o.dest.href); } |
| 214 | }).then(function () { |
| 215 | busyEnd(); |
| 216 | if (o.form) { pending.delete(o.form); } |
| 217 | }); |
| 218 | } |
| 219 | |
| 220 | function saveScroll() { |
| 221 | try { history.replaceState({ y: window.scrollY }, '', location.href); } catch (err) { } |
| 222 | } |
| 223 | |
| 224 | document.addEventListener('click', function (e) { |
| 225 | if (e.defaultPrevented || e.button !== 0 || e.metaKey || e.ctrlKey || e.shiftKey || e.altKey) { return; } |
| 226 | var a = e.target && e.target.closest ? e.target.closest('a[href]') : null; |
| 227 | if (!a || a.target || a.hasAttribute('download') || a.hasAttribute('data-hard')) { return; } |
| 228 | var href = a.getAttribute('href') || ''; |
| 229 | // Same-app paths only: `//host` is protocol-relative, another origin, and goes the browser's way. |
| 230 | if (href.charAt(0) !== '/' || href.charAt(1) === '/') { return; } |
| 231 | var url = pageUrl(href); |
| 232 | if (!url) { return; } |
| 233 | // A fragment on the page already shown: the browser scrolls by itself. |
| 234 | if (url.pathname + url.search === shown && url.hash) { return; } |
| 235 | e.preventDefault(); |
| 236 | saveScroll(); |
| 237 | load({ target: withoutHash(url), dest: url, init: GET_INIT, how: 'nav', keep: false, post: false, form: null }); |
| 238 | }, true); |
| 239 | |
| 240 | document.addEventListener('submit', function (e) { |
| 241 | var form = e.target; |
| 242 | if (!form || form.tagName !== 'FORM' || form.hasAttribute('data-hard') || form.getAttribute('target')) { return; } |
| 243 | var submitter = e.submitter || null; |
| 244 | // Per-button overrides other than the action are rare: the browser handles those. |
| 245 | if (submitter && (submitter.hasAttribute('formmethod') || submitter.hasAttribute('formenctype') || |
| 246 | submitter.hasAttribute('formtarget') || submitter.hasAttribute('data-hard'))) { return; } |
| 247 | var action = (submitter && submitter.getAttribute('formaction')) || form.getAttribute('action') || location.href; |
| 248 | var url = pageUrl(action); |
| 249 | if (!url) { return; } |
| 250 | e.preventDefault(); |
| 251 | if (pending.has(form)) { return; } |
| 252 | pending.add(form); |
| 253 | |
| 254 | var data = new FormData(form); |
| 255 | if (submitter && submitter.name) { data.append(submitter.name, submitter.value); } |
| 256 | var method = (form.getAttribute('method') || 'get').toLowerCase(); |
| 257 | |
| 258 | if (method === 'get') { |
| 259 | var q = new URLSearchParams(data).toString(); |
| 260 | var dest = withoutHash(url); |
| 261 | dest.search = q ? '?' + q : ''; |
| 262 | saveScroll(); |
| 263 | load({ target: dest, dest: dest, init: GET_INIT, how: 'nav', keep: false, post: false, form: form }); |
| 264 | return; |
| 265 | } |
| 266 | |
| 267 | var multipart = (form.enctype || '').toLowerCase().indexOf('multipart') === 0; |
| 268 | load({ |
| 269 | target: withoutHash(url), |
| 270 | dest: url, |
| 271 | init: { |
| 272 | method: 'POST', |
| 273 | headers: { accept: 'text/html' }, |
| 274 | body: multipart ? data : new URLSearchParams(data) |
| 275 | }, |
| 276 | how: 'post', |
| 277 | keep: true, |
| 278 | post: true, |
| 279 | form: form |
| 280 | }); |
| 281 | }, false); |
| 282 | |
| 283 | window.addEventListener('popstate', function () { |
| 284 | var here = location.pathname + location.search; |
| 285 | if (here === shown) { placeHash(location.hash); return; } |
| 286 | var url = pageUrl(location.href); |
| 287 | if (!url) { location.reload(); return; } |
| 288 | load({ target: withoutHash(url), dest: url, init: GET_INIT, how: 'pop', keep: false, post: false, form: null }); |
| 289 | }); |
| 290 | |
| 291 | // Filter controls submit their form on change. |
| 292 | document.addEventListener('change', function (e) { |
| 293 | var c = e.target && e.target.closest ? e.target.closest('[data-autosubmit]') : null; |
| 294 | if (!c || !c.form) { return; } |
| 295 | if (c.form.requestSubmit) { c.form.requestSubmit(); } else { c.form.submit(); } |
| 296 | }); |
| 297 | |
| 298 | // A filtered view asked for in place: the URL is replaced (no history entry per change), fields |
| 299 | // and caret come through the swap, and the scroll stays put. |
| 300 | window.__forgeQuery = function (href) { |
| 301 | var url = pageUrl(href); |
| 302 | if (!url) { location.assign(href); return; } |
| 303 | load({ target: withoutHash(url), dest: url, init: GET_INIT, how: 'query', keep: true, post: false, form: null }); |
| 304 | }; |
| 305 | })(); |