feat(regex_url_paths): add regex_group_names to handle consistency with serializers

By adding `regex_named_groups` to regex route configurations we can consistently map
regex matching groups to component parameters.

This should fix #7554.

Closes #7694

modules/@angular/router-deprecated/src/route_config/route_config_impl.ts

@@ -22,14 +22,17 @@ export abstract class AbstractRoute implements RouteDefinition {
   useAsDefault: boolean;
   path: string;
   regex: string;
+  regex_group_names: string[];
   serializer: RegexSerializer;
   data: {[key: string]: any};
 
-  constructor({name, useAsDefault, path, regex, serializer, data}: RouteDefinition) {
+  constructor({name, useAsDefault, path, regex, regex_group_names, serializer,
+               data}: RouteDefinition) {
     this.name = name;
     this.useAsDefault = useAsDefault;
     this.path = path;
     this.regex = regex;
+    this.regex_group_names = regex_group_names;
     this.serializer = serializer;
     this.data = data;
   }
@@ -62,12 +65,14 @@ export class Route extends AbstractRoute {
   component: any;
   aux: string = null;
 
-  constructor({name, useAsDefault, path, regex, serializer, data, component}: RouteDefinition) {
+  constructor({name, useAsDefault, path, regex, regex_group_names, serializer, data,
+               component}: RouteDefinition) {
     super({
       name: name,
       useAsDefault: useAsDefault,
       path: path,
       regex: regex,
+      regex_group_names: regex_group_names,
       serializer: serializer,
       data: data
     });
@@ -99,12 +104,14 @@ export class Route extends AbstractRoute {
 export class AuxRoute extends AbstractRoute {
   component: any;
 
-  constructor({name, useAsDefault, path, regex, serializer, data, component}: RouteDefinition) {
+  constructor({name, useAsDefault, path, regex, regex_group_names, serializer, data,
+               component}: RouteDefinition) {
     super({
       name: name,
       useAsDefault: useAsDefault,
       path: path,
       regex: regex,
+      regex_group_names: regex_group_names,
       serializer: serializer,
       data: data
     });
@@ -141,12 +148,14 @@ export class AsyncRoute extends AbstractRoute {
   loader: () => Promise<Type>;
   aux: string = null;
 
-  constructor({name, useAsDefault, path, regex, serializer, data, loader}: RouteDefinition) {
+  constructor({name, useAsDefault, path, regex, regex_group_names, serializer, data,
+               loader}: RouteDefinition) {
     super({
       name: name,
       useAsDefault: useAsDefault,
       path: path,
       regex: regex,
+      regex_group_names: regex_group_names,
       serializer: serializer,
       data: data
     });
@@ -179,12 +188,14 @@ export class AsyncRoute extends AbstractRoute {
 export class Redirect extends AbstractRoute {
   redirectTo: any[];
 
-  constructor({name, useAsDefault, path, regex, serializer, data, redirectTo}: RouteDefinition) {
+  constructor({name, useAsDefault, path, regex, regex_group_names, serializer, data,
+               redirectTo}: RouteDefinition) {
     super({
       name: name,
       useAsDefault: useAsDefault,
       path: path,
       regex: regex,
+      regex_group_names: regex_group_names,
       serializer: serializer,
       data: data
     });

modules/@angular/router-deprecated/src/route_definition.dart

@@ -5,6 +5,7 @@ abstract class RouteDefinition {
   final String name;
   final bool useAsDefault;
   final String regex;
+  final List<String> regex_group_names;
   final Function serializer;
-  const RouteDefinition({this.path, this.name, this.useAsDefault : false, this.regex, this.serializer});
+  const RouteDefinition({this.path, this.name, this.useAsDefault : false, this.regex, this.regex_group_names, this.serializer});
 }

modules/@angular/router-deprecated/src/route_definition.ts

@@ -16,6 +16,7 @@ export interface RouteDefinition {
   path?: string;
   aux?: string;
   regex?: string;
+  regex_group_names?: string[];
   serializer?: RegexSerializer;
   component?: Type | ComponentDefinition;
   loader?: () => Promise<Type>;

modules/@angular/router-deprecated/src/rules/route_paths/regex_route_path.ts

@@ -1,10 +1,21 @@
 import {RegExpWrapper, RegExpMatcherWrapper, isBlank} from '../../../src/facade/lang';
+import {BaseException} from '@angular/core';
 import {Url} from '../../url_parser';
 import {RoutePath, GeneratedUrl, MatchedUrl} from './route_path';
 
 
 export interface RegexSerializer { (params: {[key: string]: any}): GeneratedUrl; }
 
+function computeNumberOfRegexGroups(regex: string): number {
+  // cleverly compute regex groups by appending an alternative empty matching
+  // pattern and match against an empty string, the resulting match still
+  // receives all the other groups
+  var test_regex = RegExpWrapper.create(regex + "|");
+  var matcher = RegExpWrapper.matcher(test_regex, '');
+  var match = RegExpMatcherWrapper.next(matcher);
+  return match.length;
+}
+
 export class RegexRoutePath implements RoutePath {
   public hash: string;
   public terminal: boolean = true;
@@ -12,9 +23,19 @@ export class RegexRoutePath implements RoutePath {
 
   private _regex: RegExp;
 
-  constructor(private _reString: string, private _serializer: RegexSerializer) {
+  constructor(private _reString: string, private _serializer: RegexSerializer,
+              private _groupNames?: Array<string>) {
     this.hash = this._reString;
     this._regex = RegExpWrapper.create(this._reString);
+    if (this._groupNames != null) {
+      var groups = computeNumberOfRegexGroups(this._reString);
+      if (groups != _groupNames.length) {
+        throw new BaseException(
+            `Regex group names [${this._groupNames.join(',')}] must contain names for \
+each matching group and a name for the complete match as its first element of regex \
+'${this._reString}'. ${groups} group names are expected.`);
+      }
+    }
   }
 
   matchUrl(url: Url): MatchedUrl {
@@ -28,7 +49,7 @@ export class RegexRoutePath implements RoutePath {
     }
 
     for (let i = 0; i < match.length; i += 1) {
-      params[i.toString()] = match[i];
+      params[this._groupNames != null ? this._groupNames[i] : i.toString()] = match[i];
     }
 
     return new MatchedUrl(urlPath, [], params, [], null);

modules/@angular/router-deprecated/src/rules/rule_set.ts

@@ -169,7 +169,7 @@ export class RuleSet {
   private _getRoutePath(config: RouteDefinition): RoutePath {
     if (isPresent(config.regex)) {
       if (isFunction(config.serializer)) {
-        return new RegexRoutePath(config.regex, config.serializer);
+        return new RegexRoutePath(config.regex, config.serializer, config.regex_group_names);
       } else {
         throw new BaseException(
             `Route provides a regex property, '${config.regex}', but no serializer property`);