[IMP] router: basic implementation of navigation guards

src/router/Link.ts

@@ -13,10 +13,10 @@ type Props = Destination;
 
 export class Link<Env extends RouterEnv> extends Component<Env, Props, {}> {
   template = LINK_TEMPLATE_NAME;
-  href: string = this.env.router.destToUrl(this.props);
+  href: string = this.env.router.destToPath(this.props);
 
   async willUpdateProps(nextProps) {
-    this.href = this.env.router.destToUrl(nextProps);
+    this.href = this.env.router.destToPath(nextProps);
   }
 
   get isActive() {

src/router/Router.ts

@@ -3,12 +3,19 @@ import { QWeb } from "../qweb/index";
 import { makeDirective } from "./directive";
 import { LINK_TEMPLATE, LINK_TEMPLATE_NAME } from "./Link";
 
-interface Route {
+type NavigationGuard = (info: {
+  env: Env;
+  to: Route | null;
+  from: Route | null;
+}) => boolean | Destination;
+
+export interface Route {
   name: string;
   path: string;
   component?: any;
   redirect?: Destination;
   params: string[];
+  beforeRouteEnter?: NavigationGuard;
 }
 
 export type RouteParams = { [key: string]: string | number };
@@ -23,6 +30,22 @@ export interface Destination {
   params?: RouteParams;
 }
 
+interface PositiveMatchResult {
+  type: "match";
+  route: Route;
+  params: RouteParams;
+}
+
+interface NegativeMatchResult {
+  type: "nomatch";
+}
+
+interface CancelledMatch {
+  type: "cancelled";
+}
+
+type MatchResult = PositiveMatchResult | NegativeMatchResult | CancelledMatch;
+
 interface Options {
   mode: Router["mode"];
 }
@@ -61,38 +84,66 @@ export class Router {
       this.routeIds.push(partialRoute.name);
     }
 
-    this.checkRoute();
-
-    this.checkAndUpdateRoute = this.checkAndUpdateRoute.bind(this);
-    window.addEventListener("popstate", this.checkAndUpdateRoute);
+    (this as any)._listener = () => this.matchAndApplyRules(this.currentPath());
+    window.addEventListener("popstate", (this as any)._listener);
 
     // setup link and directive
     env.qweb.addTemplate(LINK_TEMPLATE_NAME, LINK_TEMPLATE);
     QWeb.addDirective(makeDirective(<RouterEnv>env));
   }
 
-  navigate(to: Destination): void {
-    const url = this.destToUrl(to);
-    history.pushState({}, url, location.origin + url);
-    this.checkAndUpdateRoute();
+  //--------------------------------------------------------------------------
+  // Public API
+  //--------------------------------------------------------------------------
+
+  async start() {
+    const result = await this.matchAndApplyRules(this.currentPath());
+    if (result.type === "match") {
+      this.currentRoute = result.route;
+      this.currentParams = result.params;
+    }
   }
 
-  destToUrl(dest: Destination): string {
+  async navigate(to: Destination): Promise<void> {
+    const path = this.destToPath(to);
+    const initialName = this.currentRouteName;
+    const result = await this.matchAndApplyRules(path);
+    if (result.type === "match") {
+      const finalPath = this.routeToPath(result.route, result.params);
+      const url = location.origin + finalPath;
+      history.pushState({}, path, url);
+      this.currentRoute = result.route;
+      this.currentParams = result.params;
+    } else if (result.type === "nomatch") {
+      this.currentRoute = null;
+      this.currentParams = null;
+    }
+    if (this.currentRouteName !== initialName) {
+      this.env.qweb.forceUpdate();
+    }
+  }
+
+  destToPath(dest: Destination): string {
     this.validateDestination(dest);
-    return dest.path || this.routeToURL(this.routes[dest.to!].path, dest.params!);
+    return dest.path || this.routeToPath(this.routes[dest.to!], dest.params!);
   }
 
   get currentRouteName(): string | null {
     return this.currentRoute && this.currentRoute.name;
   }
 
+  //--------------------------------------------------------------------------
+  // Private helpers
+  //--------------------------------------------------------------------------
+
   private validateDestination(dest: Destination) {
     if ((!dest.path && !dest.to) || (dest.path && dest.to)) {
       throw new Error(`Invalid destination: ${JSON.stringify(dest)}`);
     }
   }
 
-  private routeToURL(path: string, params: RouteParams): string {
+  private routeToPath(route: Route, params: RouteParams): string {
+    const path = route.path;
     const parts = path.split("/");
     const l = parts.length;
     for (let i = 0; i < l; i++) {
@@ -106,42 +157,63 @@ export class Router {
     return parts.join("/");
   }
 
-  private checkRoute(): void {
-    let currentPath =
-      this.mode === "history" ? window.location.pathname : window.location.hash.slice(1);
-    currentPath = currentPath || "/";
+  private currentPath(): string {
+    let result = this.mode === "history" ? window.location.pathname : window.location.hash.slice(1);
+    return result || "/";
+  }
+
+  private match(path: string): MatchResult {
     for (let routeId of this.routeIds) {
       let route = this.routes[routeId];
-      let params = this.matchRoute(route.path, currentPath);
+      let params = this.getRouteParams(route, path);
       if (params) {
-        if (route.redirect) {
-          this.navigate(route.redirect);
-          return;
-        }
-        this.currentRoute = route;
-        this.currentParams = params;
-        return;
+        return {
+          type: "match",
+          route: route,
+          params: params
+        };
       }
     }
-    this.currentRoute = null;
-    this.currentParams = {};
+    return { type: "nomatch" };
   }
 
-  protected checkAndUpdateRoute(): void {
-    const initialName = this.currentRoute ? this.currentRoute.name : null;
-    this.checkRoute();
-    const currentName = this.currentRoute ? this.currentRoute.name : null;
-
-    if (currentName !== initialName) {
-      this.env.qweb.forceUpdate();
+  private async matchAndApplyRules(path: string): Promise<MatchResult> {
+    const result = this.match(path);
+    if (result.type === "match") {
+      return this.applyRules(result);
     }
+    return result;
   }
 
-  private matchRoute(routePath: string, path: string): RouteParams | false {
-    if (routePath === "*") {
+  private async applyRules(matchResult: PositiveMatchResult): Promise<MatchResult> {
+    const route = matchResult.route;
+    if (route.redirect) {
+      const path = this.destToPath(route.redirect);
+      return this.matchAndApplyRules(path);
+    }
+    if (route.beforeRouteEnter) {
+      const result = await route.beforeRouteEnter({
+        env: this.env,
+        from: this.currentRoute,
+        to: route
+      });
+      if (result === false) {
+        return { type: "cancelled" };
+      } else if (result !== true) {
+        // we want to navigate to another destination
+        const path = this.destToPath(result);
+        return this.matchAndApplyRules(path);
+      }
+    }
+
+    return matchResult;
+  }
+
+  private getRouteParams(route: Route, path: string): RouteParams | false {
+    if (route.path === "*") {
       return {};
     }
-    const descrParts = routePath.split("/");
+    const descrParts = route.path.split("/");
     const targetParts = path.split("/");
     const l = descrParts.length;
     if (l !== targetParts.length) {

tests/router/TestRouter.ts

@@ -3,7 +3,7 @@ import { QWeb } from "../../src/qweb/index";
 
 export class TestRouter extends Router {
   destroy() {
-    window.removeEventListener("popstate", this.checkAndUpdateRoute);
+    window.removeEventListener("popstate", (this as any)._listener);
     delete QWeb.DIRECTIVE_NAMES.routecomponent;
     QWeb.DIRECTIVES = QWeb.DIRECTIVES.filter(d => d.name !== "routecomponent");
 

tests/router/directive.test.ts

@@ -43,12 +43,12 @@ describe("router directive t-routecomponent", () => {
     ];
 
     router = new TestRouter(env, routes, { mode: "history" });
-    router.navigate({ to: "about" });
+    await router.navigate({ to: "about" });
     const app = new App(env);
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>About</span></div>");
 
-    router.navigate({ to: "users" });
+    await router.navigate({ to: "users" });
     await nextTick();
     expect(fixture.innerHTML).toBe("<div><span>Users</span></div>");
     expect(env.qweb.templates.App.fn.toString()).toMatchSnapshot();
@@ -70,7 +70,7 @@ describe("router directive t-routecomponent", () => {
 
     const routes = [{ name: "book", path: "/book/{{title}}", component: Book }];
     router = new TestRouter(env, routes, { mode: "history" });
-    router.navigate({ to: "book", params: { title: "1984" } });
+    await router.navigate({ to: "book", params: { title: "1984" } });
     const app = new App(env);
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>Book 1984</span></div>");
@@ -97,7 +97,7 @@ describe("router directive t-routecomponent", () => {
 
     const routes = [{ name: "book", path: "/book/{{title}}/{{val.number}}", component: Book }];
     router = new TestRouter(env, routes, { mode: "history" });
-    router.navigate({ to: "book", params: { title: "1984", val: "123" } });
+    await router.navigate({ to: "book", params: { title: "1984", val: "123" } });
     const app = new App(env);
     await app.mount(fixture);
     expect(fixture.innerHTML).toBe("<div><span>Book 1984|124</span></div>");

tests/router/router.test.ts

@@ -1,4 +1,4 @@
-import { Destination, Router, RouterEnv } from "../../src/router/Router";
+import { Destination, Router, RouterEnv, Route } from "../../src/router/Router";
 import { makeTestEnv } from "../helpers";
 import { TestRouter } from "./TestRouter";
 
@@ -7,6 +7,7 @@ let router: TestRouter | null = null;
 
 beforeEach(() => {
   env = <RouterEnv>makeTestEnv();
+  window.history.pushState({}, "/", "/");
 });
 
 afterEach(() => {
@@ -26,82 +27,138 @@ describe("router miscellaneous", () => {
   });
 });
 
-describe("routeToURL", () => {
-  const routeToURL = Router.prototype["routeToURL"];
+describe("routeToPath", () => {
+  const routeToPath = Router.prototype["routeToPath"];
   test("simple non parameterized path", () => {
-    expect(routeToURL("/abc", {})).toBe("/abc");
-    expect(routeToURL("/abc/def", {})).toBe("/abc/def");
-    expect(routeToURL("/abc", { val: 12 })).toBe("/abc");
+    expect(routeToPath({path: "/abc"} as Route, {})).toBe("/abc");
+    expect(routeToPath({path: "/abc/def"} as Route, {})).toBe("/abc/def");
+    expect(routeToPath({path: "/abc"} as Route, { val: 12 })).toBe("/abc");
   });
 
   test("simple parameterized path", () => {
-    expect(routeToURL("/abc/{{def}}", { def: 34 })).toBe("/abc/34");
+    expect(routeToPath({path: "/abc/{{def}}"} as Route, { def: 34 })).toBe("/abc/34");
   });
 });
 
-describe("destToURL", () => {
+describe("destToPath", () => {
   test("validate destination shape", () => {
     router = new TestRouter(env, [{ name: "someroute", path: "/some/path" }]);
     expect(() => {
-      router!.destToUrl({ abc: 123 } as Destination);
+      router!.destToPath({ abc: 123 } as Destination);
     }).toThrow('Invalid destination: {"abc":123}');
 
     expect(() => {
-      router!.destToUrl({ to: "someroute" } as Destination);
+      router!.destToPath({ to: "someroute" } as Destination);
     }).not.toThrow();
 
     expect(() => {
-      router!.destToUrl({ path: "/someroute", to: "otherroute" } as Destination);
+      router!.destToPath({ path: "/someroute", to: "otherroute" } as Destination);
     }).toThrow();
   });
 });
 
-describe("match routes", () => {
-  const matchRoute = Router.prototype["matchRoute"];
+describe("getRouteParams", () => {
+  const getRouteParams = Router.prototype["getRouteParams"];
   test("properly match simple routes", () => {
     // simple route
-    expect(matchRoute("/home", "/home")).toEqual({});
+    expect(getRouteParams({path: "/home"} as Route, "/home")).toEqual({});
 
     // no match
-    expect(matchRoute("/home", "/otherpath")).toEqual(false);
+    expect(getRouteParams({path: "/home"} as Route, "/otherpath")).toEqual(false);
 
     // fallback route
-    expect(matchRoute("*", "somepath")).toEqual({});
+    expect(getRouteParams({path: "*"} as Route, "somepath")).toEqual({});
   });
 
   test("match some parameterized routes", () => {
-    expect(matchRoute("/invoices/{{id}}", "/invoices/3")).toEqual({
+    expect(getRouteParams({path: "/invoices/{{id}}"} as Route, "/invoices/3")).toEqual({
       id: "3"
     });
   });
 
   test("can convert to number if needed", () => {
-    expect(matchRoute("/invoices/{{id.number}}", "/invoices/3")).toEqual({
+    expect(getRouteParams({path: "/invoices/{{id.number}}"} as Route, "/invoices/3")).toEqual({
       id: 3
     });
   });
 });
 
 describe("redirect", () => {
-  test("can redirect to other route", () => {
+  test("can redirect to other route", async () => {
     router = new TestRouter(env, [
       { name: "routea", path: "/some/path" },
       { name: "routeb", path: "/some/other/path", redirect: { to: "routea" } }
     ]);
 
-    router.navigate({ to: "routeb" });
+    await router.start();
+    expect(window.location.pathname).toBe("/");
+    await router.navigate({ to: "routeb" });
     expect(window.location.pathname).toBe("/some/path");
     expect(router.currentRouteName).toBe("routea");
   });
 
-  test("can redirect to other path", () => {
+  test("can redirect to other path", async () => {
     router = new TestRouter(env, [
       { name: "routea", path: "/some/path" },
       { name: "routeb", path: "/some/other/path", redirect: { path: "/some/path" } }
     ]);
+    router.navigate = jest.fn(router.navigate);
 
-    router.navigate({ to: "routeb" });
+    await router.start();
+    await router.navigate({ to: "routeb" });
+
+    // once because we ask for it, once because it is redirected
+    // expect(router.navigate).toBeCalledTimes(2);
     expect(window.location.pathname).toBe("/some/path");
     expect(router.currentRouteName).toBe("routea");
   });
 });
+
+describe("beforeRouteEnter", () => {
+  test("navigation guard is called and properly handle return true", async () => {
+    expect(window.location.pathname).not.toBe("/some/path");
+    const guard = jest.fn(() => true);
+    router = new TestRouter(env, [{ name: "route", path: "/some/path", beforeRouteEnter: guard }]);
+
+    await router.start();
+    await router.navigate({ to: "route" });
+    expect(guard).toBeCalledTimes(1);
+    expect(window.location.pathname).toBe("/some/path");
+    expect(router.currentRouteName).toBe("route");
+  });
+
+  test("navigation is cancelled if guard return false", async () => {
+    expect(window.location.pathname).toBe("/");
+    const guard = jest.fn(() => false);
+    router = new TestRouter(env, [
+        { name: "routea", path: "/some/patha"},
+        { name: "routeb", path: "/some/pathb", beforeRouteEnter: guard }
+        ]);
+
+    await router.start();
+    await router.navigate({ to: "routea" });
+    expect(window.location.pathname).toBe("/some/patha");
+    await router.navigate({ to: "routeb" });
+    expect(guard).toBeCalledTimes(1);
+    expect(window.location.pathname).toBe("/some/patha");
+    expect(router.currentRouteName).toBe("routea");
+  });
+
+  test("navigation is redirected if guard decides so", async () => {
+    expect(window.location.pathname).toBe("/");
+    const guard = jest.fn(() => {return {to: "routec"}});
+    router = new TestRouter(env, [
+        { name: "routea", path: "/some/patha"},
+        { name: "routeb", path: "/some/pathb", beforeRouteEnter: guard },
+        { name: "routec", path: "/some/pathc"},
+        ]);
+
+    await router.start();
+    await router.navigate({ to: "routea" });
+    expect(window.location.pathname).toBe("/some/patha");
+    await router.navigate({ to: "routeb" });
+    expect(guard).toBeCalledTimes(1);
+    expect(window.location.pathname).toBe("/some/pathc");
+    expect(router.currentRouteName).toBe("routec");
+  });
+});