Mercurial > urweb
view lib/js/urweb.js @ 712:915ec60592d4
More flexible foreign keying
author | Adam Chlipala <adamc@hcoop.net> |
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date | Thu, 09 Apr 2009 13:59:34 -0400 |
parents | a5d8b470d7ca |
children | 6fc633d990e7 |
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// Lists function cons(v, ls) { return { next : ls, data : v }; } function concat(ls1, ls2) { return (ls1 ? cons(ls1.data, concat(ls1.next, ls2)) : ls2); } function member(x, ls) { for (; ls; ls = ls.next) if (ls.data == x) return true; return false; } function remove(x, ls) { return (ls ? (ls.data == x ? ls.next : cons(ls.data, remove(x, ls.next))) : null); } function union(ls1, ls2) { return (ls1 ? (member(ls1.data, ls2) ? union(ls1.next, ls2) : cons(ls1.data, union(ls1.next, ls2))) : ls2); } function length(ls) { return (ls ? 1 + length(ls.next) : 0); } // Embedding closures in XML strings function cs(f) { return {closure: f}; } function isWeird(v) { return v.closure != null || v.cat1 != null; } function cat(s1, s2) { if (isWeird(s1) || isWeird(s2)) return {cat1: s1, cat2: s2}; else return s1 + s2; } var closures = []; var freeClosures = null; function newClosure(f) { var n; if (freeClosures == null) { n = closures.length; } else { n = freeClosures.data; freeClosures = freeClosures.next; } closures[n] = f; return n; } function freeClosure(n) { closures[n] = null; freeClosures = cons(n, freeClosures); } function cr(n) { return closures[n](); } function flatten(cls, tr) { if (tr.cat1 != null) return flatten(cls, tr.cat1) + flatten(cls, tr.cat2); else if (tr.closure != null) { var cl = newClosure(tr.closure); cls.v = cons(cl, cls.v); return "cr(" + cl + ")"; } else return tr; } // Dynamic tree management function populate(node) { var s = node.signal; var oldSources = node.sources; var sr = s(); var newSources = sr.sources; for (var sp = oldSources; sp; sp = sp.next) if (!member(sp.data, newSources)) sp.data.dyns = remove(node, sp.data.dyns); for (var sp = newSources; sp; sp = sp.next) if (!member(sp.data, oldSources)) sp.data.dyns = cons(node, sp.data.dyns); node.sources = newSources; node.recreate(sr.data); } function sc(v) { return {data : v, dyns : null}; } function sv(s, v) { s.data = v; for (var ls = s.dyns; ls; ls = ls.next) if (!ls.dead) populate(ls.data); } function sg(s) { return s.data; } function ss(s) { return function() { return {sources : cons(s, null), data : s.data } }; } function sr(v) { return function() { return {sources : null, data : v } }; } function sb(x,y) { return function() { var xr = x(); var yr = y(xr.data)(); return {sources : union(xr.sources, yr.sources), data : yr.data}; }; } function lastParent() { var pos = document; while (pos.lastChild && pos.lastChild.nodeType == 1) pos = pos.lastChild; return pos.parentNode; } function addNode(node) { if (thisScript) { thisScript.parentNode.appendChild(node); thisScript.parentNode.removeChild(thisScript); } else lastParent().appendChild(node); } var thisScript = null; function runScripts(node) { var savedScript = thisScript; var scripts = node.getElementsByTagName("script"), scriptsCopy = []; var len = scripts.length; for (var i = 0; i < len; ++i) scriptsCopy[i] = scripts[i]; for (var i = 0; i < len; ++i) { thisScript = scriptsCopy[i]; eval(thisScript.textContent); } thisScript = savedScript; } // Dynamic tree entry points var dynDepth = 0; function dyn(s) { var x = document.createElement("span"); x.dead = false; x.signal = s; x.sources = null; x.closures = null; x.recreate = function(v) { for (var ls = x.closures; ls; ls = ls.next) freeClosure(ls.data); var spans = x.getElementsByTagName("span"); for (var i = 0; i < spans.length; ++i) { var span = spans[i]; span.dead = true; for (var ls = span.sources; ls; ls = ls.next) ls.data.dyns = remove(span, ls.data.dyns); for (var ls = span.closures; ls; ls = ls.next) freeClosure(ls.data); } var cls = {v : null}; x.innerHTML = flatten(cls, v); x.closures = cls.v; runScripts(x); }; addNode(x); populate(x); } function inp(t, s) { var x = document.createElement(t); x.dead = false; x.signal = ss(s); x.sources = null; x.recreate = function(v) { if (x.value != v) x.value = v; }; populate(x); addNode(x); x.onkeyup = function() { sv(s, x.value) }; return x; } // Basic string operations function eh(x) { return x.split("&").join("&").split("<").join("<").split(">").join(">"); } function ts(x) { return x.toString() } function bs(b) { return (b ? "True" : "False") } function pi(s) { var r = parseInt(s); if (r.toString() == s) return r; else throw "Can't parse int: " + s; } function pfl(s) { var r = parseFloat(s); if (r.toString() == s) return r; else throw "Can't parse float: " + s; } function uf(s) { return escape(s).replace(new RegExp ("/", "g"), "%2F"); } function uu(s) { return unescape(s).replace(new RegExp ("\\+", "g"), " "); } // Error handling function whine(msg) { alert(msg); throw msg; } function pf() { whine("Pattern match failure"); } // Remote calls var client_id = null; var client_pass = 0; var url_prefix = "/"; var timeout = 60; function getXHR(uri) { try { return new XMLHttpRequest(); } catch (e) { try { return new ActiveXObject("Msxml2.XMLHTTP"); } catch (e) { try { return new ActiveXObject("Microsoft.XMLHTTP"); } catch (e) { throw "Your browser doesn't seem to support AJAX."; } } } } function requestUri(xhr, uri) { xhr.open("GET", uri, true); if (client_id != null) { xhr.setRequestHeader("UrWeb-Client", client_id.toString()); xhr.setRequestHeader("UrWeb-Pass", client_pass.toString()); } xhr.send(null); } function rc(uri, parse, k) { var cls = {v : null}; uri = flatten(cls, uri); for (cl = cls.v; cl != null; cl = cl.next) freeClosure(cl.data); var xhr = getXHR(); xhr.onreadystatechange = function() { if (xhr.readyState == 4) { var isok = false; try { if (xhr.status == 200) isok = true; } catch (e) { } if (isok) k(parse(xhr.responseText)); else { whine("Error querying remote server!"); } } }; requestUri(xhr, uri); } function path_join(s1, s2) { if (s1.length > 0 && s1[s1.length-1] == '/') return s1 + s2; else return s1 + "/" + s2; } var channels = []; function newQueue() { return { front : null, back : null }; } function enqueue(q, v) { if (q.front == null) { q.front = cons(v, null); q.back = q.front; } else { var node = cons(v, null); q.back.next = node; q.back = node; } } function dequeue(q) { if (q.front == null) return null; else { var r = q.front.data; q.front = q.front.next; if (q.front == null) q.back = null; return r; } } function newChannel() { return { msgs : newQueue(), listeners : newQueue() }; } function listener() { var uri = path_join(url_prefix, ".msgs"); var xhr = getXHR(); var tid, orsc, onTimeout; var connect = function () { xhr.onreadystatechange = orsc; tid = window.setTimeout(onTimeout, timeout * 500); requestUri(xhr, uri); } orsc = function() { if (xhr.readyState == 4) { window.clearTimeout(tid); var isok = false; try { if (xhr.status == 200) isok = true; } catch (e) { } if (isok) { var lines = xhr.responseText.split("\n"); if (lines.length < 2) return; // throw "Empty message from remote server"; for (var i = 0; i+1 < lines.length; i += 2) { var chn = lines[i]; var msg = lines[i+1]; if (chn < 0) whine("Out-of-bounds channel in message from remote server"); var ch; if (chn >= channels.length || channels[chn] == null) { ch = newChannel(); channels[chn] = ch; } else ch = channels[chn]; var listener = dequeue(ch.listeners); if (listener == null) { enqueue(ch.msgs, msg); } else { listener(msg); } } connect(); } else { /*try { whine("Error querying remote server for messages! " + xhr.status); } catch (e) { }*/ } } }; onTimeout = function() { xhr.abort(); connect(); }; connect(); } function rv(chn, parse, k) { if (chn == null) return; if (chn < 0) whine("Out-of-bounds channel receive"); var ch; if (chn >= channels.length || channels[chn] == null) { ch = newChannel(); channels[chn] = ch; } else ch = channels[chn]; var msg = dequeue(ch.msgs); if (msg == null) { enqueue(ch.listeners, function(msg) { k(parse(msg))(null); }); } else { k(parse(msg))(null); } } // App-specific code