feat(router-store): add selectors for router state (#1874)

Closes #1854

modules/router-store/spec/router_selectors.spec.ts

@@ -0,0 +1,164 @@
+import { RouterReducerState, getSelectors } from '@ngrx/router-store';
+import { RouterStateSelectors } from '../src/models';
+
+const mockData = {
+  state: {
+    root: {
+      params: {},
+      paramMap: {
+        params: {},
+      },
+      data: {},
+      url: [],
+      outlet: 'primary',
+      routeConfig: null,
+      queryParams: {},
+      queryParamMap: {
+        params: {},
+      },
+      fragment: null,
+      firstChild: {
+        params: {},
+        paramMap: {
+          params: {},
+        },
+        data: {},
+        url: [
+          {
+            path: 'login',
+            parameters: {},
+          },
+        ],
+        outlet: 'primary',
+        routeConfig: {
+          path: 'login',
+        },
+        queryParams: {
+          id: 3,
+        },
+        queryParamMap: {
+          params: {},
+        },
+        firstChild: {
+          params: {
+            id: 'etyDDwAAQBAJ',
+          },
+          paramMap: {
+            params: {
+              id: 'etyDDwAAQBAJ',
+            },
+          },
+          data: {
+            testData: 'test-data',
+          },
+          url: [
+            {
+              path: 'etyDDwAAQBAJ',
+              parameters: {},
+            },
+          ],
+          outlet: 'primary',
+          routeConfig: {
+            path: ':id',
+          },
+          queryParams: {},
+          queryParamMap: {
+            params: {},
+          },
+          children: [],
+        },
+        fragment: null,
+        children: [],
+      },
+      children: [
+        {
+          params: {},
+          paramMap: {
+            params: {},
+          },
+          data: {},
+          url: [
+            {
+              path: 'login',
+              parameters: {},
+            },
+          ],
+          outlet: 'primary',
+          routeConfig: {
+            path: 'login',
+          },
+          queryParams: {},
+          queryParamMap: {
+            params: {},
+          },
+          children: [],
+        },
+      ],
+    },
+    url: '/login',
+  },
+  navigationId: 1,
+};
+describe('Router State Selectors', () => {
+  describe('Composed Selectors', () => {
+    interface State {
+      router: RouterReducerState<any>;
+    }
+
+    let selectors: RouterStateSelectors<State>;
+    let state: State;
+
+    beforeEach(() => {
+      state = {
+        router: mockData,
+      };
+
+      selectors = getSelectors((state: State) => state.router);
+    });
+    it('should create selectCurrentRoute selector for selecting the current route', () => {
+      const result = selectors.selectCurrentRoute(state);
+
+      expect(result).toEqual(state.router.state.root.firstChild.firstChild);
+    });
+    it('should return undefined from selectCurrentRoute if routerState does not exist', () => {
+      interface State {
+        router: any;
+      }
+      let state: State;
+      state = {
+        router: undefined,
+      };
+      selectors = getSelectors((state: State) => state.router);
+
+      const result = selectors.selectCurrentRoute(state);
+
+      expect(result).toEqual(undefined);
+    });
+    it('should create a selector for selecting the query params', () => {
+      const result = selectors.selectQueryParams(state);
+
+      expect(result).toEqual(
+        state.router.state.root.firstChild.firstChild.queryParams
+      );
+    });
+    it('should create a selector for selecting the route params', () => {
+      const result = selectors.selectRouteParams(state);
+
+      expect(result).toEqual(
+        state.router.state.root.firstChild.firstChild.params
+      );
+    });
+    it('should create a selector for selecting the route data', () => {
+      const result = selectors.selectRouteData(state);
+
+      expect(result).toEqual(
+        state.router.state.root.firstChild.firstChild.data
+      );
+    });
+    it('should create a selector for selecting the url', () => {
+      const result = selectors.selectUrl(state);
+
+      expect(result).toEqual(state.router.state.url);
+    });
+  });
+});

modules/router-store/src/index.ts

@@ -35,3 +35,4 @@ export {
   MinimalRouterStateSnapshot,
   MinimalRouterStateSerializer,
 } from './serializers';
+export { getSelectors } from './router_selectors';

modules/router-store/src/models.ts

@@ -0,0 +1,9 @@
+import { Data, Params } from '@angular/router';
+
+export interface RouterStateSelectors<V> {
+  selectCurrentRoute: (state: V) => any;
+  selectQueryParams: (state: V) => Params;
+  selectRouteParams: (state: V) => Params;
+  selectRouteData: (state: V) => Data;
+  selectUrl: (state: V) => string;
+}

modules/router-store/src/router_selectors.ts

@@ -0,0 +1,49 @@
+import { RouterReducerState } from '@ngrx/router-store';
+import { createSelector } from '@ngrx/store';
+import { RouterStateSelectors } from './models';
+
+export function getSelectors<V>(
+  selectState: (state: V) => RouterReducerState<any>
+): RouterStateSelectors<V>;
+export function getSelectors<V>(
+  selectState: (state: V) => RouterReducerState<any>
+): RouterStateSelectors<V> {
+  const selectRouterState = createSelector(
+    selectState,
+    router => router && router.state
+  );
+  const selectCurrentRoute = createSelector(selectRouterState, routerState => {
+    if (!routerState) {
+      return undefined;
+    }
+    let route = routerState.root;
+    while (route.firstChild) {
+      route = route.firstChild;
+    }
+    return route;
+  });
+  const selectQueryParams = createSelector(
+    selectCurrentRoute,
+    route => route && route.queryParams
+  );
+  const selectRouteParams = createSelector(
+    selectCurrentRoute,
+    route => route && route.params
+  );
+  const selectRouteData = createSelector(
+    selectCurrentRoute,
+    route => route && route.data
+  );
+  const selectUrl = createSelector(
+    selectRouterState,
+    routerState => routerState && routerState.url
+  );
+
+  return {
+    selectCurrentRoute,
+    selectQueryParams,
+    selectRouteParams,
+    selectRouteData,
+    selectUrl,
+  };
+}

projects/ngrx.io/content/guide/router-store/selectors.md

@@ -0,0 +1,33 @@
+# Router selectors
+
+The `getSelectors` method supplied within `@ngrx/router-store` provides functions for selecting common information from the router state.
+
+The `getSelectors` method takes a selector function as its only argument to select the piece of state where the router state is being stored.
+The example below shows how to provide a selector for the top level `router` key in your state object.
+
+**Note:** The `getSelectors` method works with the `routerReducer` provided by `@ngrx/router-store`. If you use a [custom serializer](guide/router-store/configuration#custom-router-state-serializer), you'll need to provide your own selectors.
+
+Usage:
+
+`reducers/index.ts`
+
+```ts
+import { getSelectors, RouterReducerState } from '@ngrx/router-store';
+
+export interface State {
+  router: fromRouter.RouterReducerState<any>;
+}
+
+export const selectRouter = createFeatureSelector<
+  State,
+  fromRouter.RouterReducerState<any>
+>('router');
+
+const {
+  selectQueryParams,    // select the current route query params
+  selectRouteParams,    // select the current route params
+  selectRouteData,      // select the current route data
+  selectUrl,            // select the current url
+} = getSelectors(selectRouter);
+
+```

projects/ngrx.io/content/navigation.json

@@ -192,6 +192,10 @@
           "title": "Actions",
           "url": "guide/router-store/actions"
         },
+        {
+          "title": "Selectors",
+          "url": "guide/router-store/selectors"
+        },
         {
           "title": "Configuration",
           "url": "guide/router-store/configuration"