feat(router): implement recognizer

modules/angular2/src/alt_router/recognize.ts

@@ -0,0 +1,84 @@
+import {RouteSegment, UrlSegment, Tree} from './segments';
+import {RoutesMetadata, RouteMetadata} from './metadata/metadata';
+import {Type, isPresent, stringify} from 'angular2/src/facade/lang';
+import {PromiseWrapper} from 'angular2/src/facade/promise';
+import {BaseException} from 'angular2/src/facade/exceptions';
+import {ComponentResolver} from 'angular2/core';
+import {reflector} from 'angular2/src/core/reflection/reflection';
+
+export function recognize(componentResolver: ComponentResolver, type: Type,
+                          url: Tree<UrlSegment>): Promise<Tree<RouteSegment>> {
+  return _recognize(componentResolver, type, url, url.root)
+      .then(nodes => new Tree<RouteSegment>(nodes));
+}
+
+function _recognize(componentResolver: ComponentResolver, type: Type, url: Tree<UrlSegment>,
+                    current: UrlSegment): Promise<RouteSegment[]> {
+  let metadata = _readMetadata(type);  // should read from the factory instead
+
+  let matched;
+  try {
+    matched = _match(metadata, url, current);
+  } catch (e) {
+    return PromiseWrapper.reject(e, null);
+  }
+
+  return componentResolver.resolveComponent(matched.route.component)
+      .then(factory => {
+        let segment = new RouteSegment(matched.consumedUrlSegments, matched.parameters, "",
+                                       matched.route.component, factory);
+
+        if (isPresent(matched.leftOver)) {
+          return _recognize(componentResolver, matched.route.component, url, matched.leftOver)
+              .then(children => [segment].concat(children));
+        } else {
+          return [segment];
+        }
+      });
+}
+
+function _match(metadata: RoutesMetadata, url: Tree<UrlSegment>,
+                current: UrlSegment): _MatchingResult {
+  for (let r of metadata.routes) {
+    let matchingResult = _matchWithParts(r, url, current);
+    if (isPresent(matchingResult)) {
+      return matchingResult;
+    }
+  }
+  throw new BaseException("Cannot match any routes");
+}
+
+function _matchWithParts(route: RouteMetadata, url: Tree<UrlSegment>,
+                         current: UrlSegment): _MatchingResult {
+  let parts = route.path.split("/");
+  let parameters = {};
+  let consumedUrlSegments = [];
+
+  let u = current;
+  for (let i = 0; i < parts.length; ++i) {
+    consumedUrlSegments.push(u);
+    let p = parts[i];
+    if (p.startsWith(":")) {
+      let segment = u.segment;
+      parameters[p.substring(1)] = segment;
+    } else if (p != u.segment) {
+      return null;
+    }
+    u = url.firstChild(u);
+  }
+  return new _MatchingResult(route, consumedUrlSegments, parameters, u);
+}
+
+class _MatchingResult {
+  constructor(public route: RouteMetadata, public consumedUrlSegments: UrlSegment[],
+              public parameters: {[key: string]: string}, public leftOver: UrlSegment) {}
+}
+
+function _readMetadata(componentType: Type) {
+  let metadata = reflector.annotations(componentType).filter(f => f instanceof RoutesMetadata);
+  if (metadata.length === 0) {
+    throw new BaseException(
+        `Component '${stringify(componentType)}' does not have route configuration`);
+  }
+  return metadata[0];
+}