Remove initialPath

This commit also changes the args that are passed to the dispatch
callback. Instead of passing the Transition object, the signature
is now callback(error, abortReason). Of course, both args are null/
undefined if there was neither an error or the transition was not
aborted.

This is going to give us a super-clean API for server-side rendering.

Author: mjackson

modules/components/Routes.js

@@ -3,7 +3,6 @@ var warning = require('react/lib/warning');
 var invariant = require('react/lib/invariant');
 var canUseDOM = require('react/lib/ExecutionEnvironment').canUseDOM;
 var copyProperties = require('react/lib/copyProperties');
-var PathStore = require('../stores/PathStore');
 var HashLocation = require('../locations/HashLocation');
 var reversedArray = require('../utils/reversedArray');
 var Transition = require('../utils/Transition');
@@ -264,13 +263,11 @@ function computeHandlerProps(matches, query) {
 
 var BrowserTransitionHandling = {
 
-  handleTransitionError: function (component, error) {
+  handleError: function (component, error) {
     throw error; // This error probably originated in a transition hook.
   },
 
-  handleAbortedTransition: function (component, transition) {
-    var reason = transition.abortReason;
-
+  handleAbort: function (component, reason) {
     if (reason instanceof Redirect) {
       component.replaceWith(reason.to, reason.params, reason.query);
     } else {
@@ -282,11 +279,11 @@ var BrowserTransitionHandling = {
 
 var ServerTransitionHandling = {
 
-  handleTransitionError: function (component, error) {
+  handleError: function (component, error) {
     // TODO
   },
 
-  handleAbortedTransition: function (component, transition) {
+  handleAbort: function (component, reason) {
     // TODO
   }
 
@@ -312,7 +309,6 @@ var Routes = React.createClass({
   mixins: [ ActiveContext, LocationContext, RouteContext, ScrollContext ],
 
   propTypes: {
-    initialPath: React.PropTypes.string,
     onChange: React.PropTypes.func
   },
 
@@ -322,44 +318,6 @@ var Routes = React.createClass({
     };
   },
 
-  componentWillMount: function () {
-    this.handlePathChange(this.props.initialPath);
-  },
-
-  componentDidMount: function () {
-    PathStore.addChangeListener(this.handlePathChange);
-  },
-
-  componentWillUnmount: function () {
-    PathStore.removeChangeListener(this.handlePathChange);
-  },
-
-  handlePathChange: function (_path) {
-    var path = _path || PathStore.getCurrentPath();
-    var actionType = PathStore.getCurrentActionType();
-
-    if (this.state.path === path)
-      return; // Nothing to do!
-
-    if (this.state.path)
-      this.recordScroll(this.state.path);
-
-    var self = this;
-
-    this.dispatch(path, function (error, transition) {
-      if (error) {
-        TransitionHandling.handleTransitionError(self, error);
-      } else if (transition.isAborted) {
-        TransitionHandling.handleAbortedTransition(self, transition);
-      } else {
-        self.updateScroll(path, actionType);
-
-        if (self.props.onChange)
-          self.props.onChange.call(self);
-      }
-    });
-  },
-
   /**
    * Performs a depth-first search for the first route in the tree that matches on
    * the given path. Returns an array of all routes in the tree leading to the one
@@ -381,10 +339,32 @@ var Routes = React.createClass({
     return findMatches(Path.withoutQuery(path), this.getRoutes(), this.props.defaultRoute, this.props.notFoundRoute);
   },
 
+  updateLocation: function (path, actionType) {
+    if (this.state.path === path)
+      return; // Nothing to do!
+
+    if (this.state.path)
+      this.recordScroll(this.state.path);
+
+    this.dispatch(path, actionType, function (error, abortReason) {
+      if (error) {
+        TransitionHandling.handleError(this, error);
+      } else if (abortReason) {
+        TransitionHandling.handleAbort(this, abortReason);
+      } else {
+        this.updateScroll(path, actionType);
+
+        if (this.props.onChange)
+          this.props.onChange.call(this);
+      }
+    }.bind(this));
+  },
+
   /**
-   * Performs a transition to the given path and calls callback(error, transition)
-   * with the Transition object when the transition is finished and the component's
-   * state has been updated accordingly.
+   * Performs a transition to the given path and calls callback(error, abortReason)
+   * when the transition is finished and the component's state has been updated. If
+   * there was an error, the first argument will not be null. Otherwise, if the
+   * transition was aborted for some reason, it will be given in the second arg.
    *
    * In a transition, the router first determines which routes are involved by
    * beginning with the current route, up the route tree to the first parent route
@@ -398,16 +378,13 @@ var Routes = React.createClass({
    */
   dispatch: function (path, callback) {
     var transition = new Transition(this, path);
-    var self = this;
 
     computeNextState(this, transition, function (error, nextState) {
-      if (error || nextState == null)
-        return callback(error, transition);
+      if (error || transition.isAborted || nextState == null)
+        return callback(error, transition.abortReason);
 
-      self.setState(nextState, function () {
-        callback(null, transition);
-      });
-    });
+      this.setState(nextState, callback);
+    }.bind(this));
   },
 
   /**

modules/mixins/LocationContext.js

@@ -61,8 +61,25 @@ var LocationContext = {
       'Cannot use location without a DOM'
     );
 
-    if (location)
+    if (location) {
       PathStore.setup(location);
+      this.handlePathChange();
+    }
+  },
+
+  componentDidMount: function () {
+    if (this.getLocation())
+      PathStore.addChangeListener(this.handlePathChange);
+  },
+
+  componentWillUnmount: function () {
+    if (this.getLocation())
+      PathStore.removeChangeListener(this.handlePathChange);
+  },
+
+  handlePathChange: function () {
+    if (this.updateLocation)
+      this.updateLocation(PathStore.getCurrentPath(), PathStore.getCurrentActionType());
   },
 
   /**