Ur/Web: lib/js/urweb.js comparison

comparison lib/js/urweb.js @ 729:7c6b6c3c7b79

Some client-side error handling

author	Adam Chlipala <adamc@hcoop.net>
date	Thu, 16 Apr 2009 13:47:20 -0400
parents	2197f0e24a9f
children	796e42c93c48

comparison

equal deleted inserted replaced

-:2197f0e24a9f
+:7c6b6c3c7b79
 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);
+}
+// Error handling
+function whine(msg) {
+alert(msg);
+throw msg;
+}
+function pf() {
+whine("Pattern match failure");
+}
+function runHandlers(ls, arg) {
+for (; ls; ls = ls.next)
+try {
+ls.data(arg)(null);
+} catch (v) { }
+}
+var errorHandlers = null;
+function onError(f) {
+errorHandlers = cons(f, errorHandlers);
+}
+function er(s) {
+runHandlers(errorHandlers, s);
+throw {uw_error: s};
+}
+var failHandlers = null;
+function onFail(f) {
+failHandlers = cons(f, failHandlers);
+}
+function doExn(v) {
+if (v == null || v.uw_error == null) {
+var s = (v == null ? "null" : v.toString());
+runHandlers(failHandlers, s);
+}
+}
+var disconnectHandlers = null;
+function onDisconnect(f) {
+disconnectHandlers = cons(function (_){return f}, disconnectHandlers);
+}
+function discon() {
+runHandlers(disconnectHandlers, null);
+}
+var connectHandlers = null;
+function onConnectFail(f) {
+connectHandlers = cons(function (_){return f}, connectHandlers);
+}
+function conn() {
+runHandlers(connectHandlers, null);
+}
+var serverHandlers = null;
+function onServerError(f) {
+serverHandlers = cons(f, serverHandlers);
+}
+function servErr(s) {
+runHandlers(serverHandlers, s);
 }
 // Embedding closures in XML strings
 // Dynamic tree management
 function populate(node) {
 var s = node.signal;
 var oldSources = node.sources;
-var sr = s();
+try {
-var newSources = sr.sources;
+var sr = s();
+var newSources = sr.sources;
-for (var sp = oldSources; sp; sp = sp.next)
-if (!member(sp.data, newSources))
+for (var sp = oldSources; sp; sp = sp.next)
-sp.data.dyns = remove(node, sp.data.dyns);
+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))
+for (var sp = newSources; sp; sp = sp.next)
-sp.data.dyns = cons(node, sp.data.dyns);
+if (!member(sp.data, oldSources))
+sp.data.dyns = cons(node, sp.data.dyns);
-node.sources = newSources;
-node.recreate(sr.data);
+node.sources = newSources;
+node.recreate(sr.data);
+} catch (v) {
+doExn(v);
+}
 }
 function sc(v) {
 return {data : v, dyns : null};
 }
 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);
+try {
+eval(thisScript.textContent);
+} catch (v) {
+doExn(v);
+}
 }
 thisScript = savedScript;
 }
 function pi(s) {
 var r = parseInt(s);
 if (r.toString() == s)
 return r;
 else
-throw "Can't parse int: " + s;
+er("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;
+er("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");
-}
-var errorHandlers = null;
-function onError(f) {
-errorHandlers = cons(f, errorHandlers);
-}
-function er(s) {
-for (var ls = errorHandlers; ls; ls = ls.next)
-ls.data(s)(null);
-throw {uw_error: s};
-}
-var failHandlers = null;
-function onFail(f) {
-failHandlers = cons(f, failHandlers);
-}
-function doExn(v) {
-if (v == null || v.uw_error == null) {
-var s = (v == null ? "null" : v.toString());
-for (var ls = failHandlers; ls; ls = ls.next)
-ls.data(s)(null);
-}
-}
 // Remote calls
 var client_id = null;
 try {
 if (xhr.status == 200)
 isok = true;
 } catch (e) { }
-if (isok)
+if (isok) {
-k(parse(xhr.responseText));
+try {
-else {
+k(parse(xhr.responseText));
-whine("Error querying remote server!");
+} catch (v) {
+doExn(v);
+}
+} else {
+conn();
 }
 }
 };
 requestUri(xhr, uri);
 isok = true;
 } catch (e) { }
 if (isok) {
 var lines = xhr.responseText.split("\n");
-if (lines.length < 2)
+if (lines.length < 2) {
-return; // throw "Empty message from remote server";
+discon();
+return;
+}
 for (var i = 0; i+1 < lines.length; i += 2) {
 var chn = lines[i];
 var msg = lines[i+1];
 }
 connect();
 }
 else {
-/*try {
+try {
-whine("Error querying remote server for messages! " + xhr.status);
+servError("Error querying remote server for messages: " + xhr.status);
-} catch (e) { }*/
+} catch (e) { servError("Error querying remote server for messages"); }
 }
 }
 };
 onTimeout = function() {