1 files changed, 46 insertions, 0 deletions
diff --git a/src/UrlWatcher.js b/src/UrlWatcher.js
new file mode 100644
index 00000000..1b2a9cf0
--- /dev/null
+++ b/src/UrlWatcher.js
@@ -0,0 +1,46 @@
+
+// ////////////////////////////
+// UrlWatcher
+// ////////////////////////////
+
+function UrlWatcher(location) {
+  this.location = location;
+  this.delay = 25;
+  this.setTimeout = function(fn, delay) {
+    window.setTimeout(fn, delay);
+  };
+  this.expectedUrl = location.href;
+  this.listeners = [];
+}
+
+UrlWatcher.prototype = {
+  watch: function(fn){
+    this.listeners.push(fn);
+  },
+
+  start: function() {
+    var self = this;
+    (function pull () {
+      if (self.expectedUrl !== self.location.href) {
+        foreach(self.listeners, function(listener){
+          listener(self.location.href);
+        });
+        self.expectedUrl = self.location.href;
+      }
+      self.setTimeout(pull, self.delay);
+    })();
+  },
+
+  set: function(url) {
+    var existingURL = this.location.href;
+    if (!existingURL.match(/#/))
+      existingURL += '#';
+    if (existingURL != url)
+      this.location.href = url;
+    this.existingURL = url;
+  },
+
+  get: function() {
+    return this.location.href;
+  }
+};