pushState based navigation between map-based layouts

app/assets/javascripts/router.js

@@ -0,0 +1,78 @@
+OSM.Router = function(rts) {
+  var escapeRegExp  = /[\-{}\[\]+?.,\\\^$|#\s]/g;
+  var optionalParam = /\((.*?)\)/g;
+  var namedParam    = /(\(\?)?:\w+/g;
+  var splatParam    = /\*\w+/g;
+
+  function Route(path, controller) {
+    var regexp = new RegExp('^' +
+      path.replace(escapeRegExp, '\\$&')
+        .replace(optionalParam, '(?:$1)?')
+        .replace(namedParam, function(match, optional){
+          return optional ? match : '([^\/]+)';
+        })
+        .replace(splatParam, '(.*?)') + '(?:$|[?#])');
+
+    var route = {};
+
+    route.match = function(path) {
+      return regexp.test(path);
+    };
+
+    route.run = function(action, path) {
+      var params = [];
+
+      if (path) {
+        params = regexp.exec(path).map(function(param, i) {
+          return (i > 0 && param) ? decodeURIComponent(param) : param;
+        });
+      }
+
+      (controller[action] || $.noop).apply(controller, params);
+    };
+
+    return route;
+  }
+
+  var routes = [];
+  for (var r in rts)
+    routes.push(Route(r, rts[r]));
+
+  routes.recognize = function(path) {
+    for (var i = 0; i < this.length; i++) {
+      if (this[i].match(path)) return this[i];
+    }
+  };
+
+  var currentPath = window.location.pathname,
+    currentRoute = routes.recognize(currentPath);
+
+  currentRoute.run('load', currentPath);
+
+  if (window.history && window.history.pushState) {
+    $(window).on('popstate', function() {
+      var path = window.location.pathname;
+      if (path === currentPath) return;
+      currentRoute.run('unload');
+      currentPath = path;
+      currentRoute = routes.recognize(currentPath);
+      currentRoute.run('popstate', currentPath);
+    });
+
+    return function (url) {
+      var path = url.replace(/#.*/, ''),
+        route = routes.recognize(path);
+      if (!route) return false;
+      window.history.pushState({}, document.title, url);
+      currentRoute.run('unload');
+      currentPath = path;
+      currentRoute = route;
+      currentRoute.run('pushstate', currentPath);
+      return true;
+    }
+  } else {
+    return function (url) {
+      window.location.assign(url);
+    }
+  }
+};