Angular 2: Can't resolve all parameters for Router

Question

Goal

Get routing working without losing sanity.

Error

Error: Can't resolve all parameters for Router: (?, ?, ?, ?, ?, ?, ?, ?)

---

app.routing.ts

import { ModuleWithProviders } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';

import { NavbarComponent } from './navbar/navbar.component';
import { CustomerComponent } from './customer/customer.component';

export const appRoutes: Routes = [
    { path: '', redirectTo: 'customers', pathMatch: 'full' },
    { path: 'customers', component: CustomerComponent },
];

export const routing: ModuleWithProviders = RouterModule.forRoot(appRoutes);

app.module.ts

import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { BrowserModule } from '@angular/platform-browser';

import { routing } from './app.routing';
import { AppComponent } from './app.component';
import { NavbarComponent } from './navbar/navbar.component';
import { CustomerComponent } from './customer/customer.component';

@NgModule({
    imports: [
        BrowserModule,
        FormsModule,
        routing
    ],
    declarations: [
        AppComponent,
        NavbarComponent,
        CustomerComponent,
    ],
    providers: [
        // ...
    ],
    bootstrap: [ AppComponent ]
})
export class AppModule {
    // ...
}

app.component.ts

import { RouterLink } from '@angular/router';
import { HTTP_PROVIDERS } from '@angular/http';
import { Component } from '@angular/core';

import { NavbarComponent } from './navbar/navbar.component';
import { CustomerComponent } from './customer/customer.component';

export { Config } from './config/env.config';

@Component({
    moduleId: module.id,
    selector: 'app',
    templateUrl: 'app.component.html',
    styleUrls: ['app.component.css'],
    directives: [NavbarComponent, CustomerComponent],
    providers: [HTTP_PROVIDERS, RouterLink]
})
export class AppComponent
{
    constructor() {
        // console.log('Environment config', Config);
    }

    ngOnInit() {
        // ...
    }
}

navbar.component.ts

import { Router, ROUTER_DIRECTIVES } from '@angular/router';
import { Component } from '@angular/core';

@Component({
    moduleId: module.id,
    selector: 'navbar',
    templateUrl: 'navbar.component.html',
    styleUrls: ['navbar.component.css'],
    directives: [ROUTER_DIRECTIVES],
    providers: [Router],
})
export class NavbarComponent
{
    version: string;
    versionIsVisible: boolean;

    constructor() {
        this.version = '<%= VERSION %>';
    }

    ngOnInit() {
        // ...
    }
}

app.component.html

<navbar></navbar>

<router-outlet></router-outlet>

navbar.component.html

<a routerLink="/customers">Customers</a>

Answer 1

Appreciate older post now but I had the same issue and have just resolved it.

The error advises Angular cannot resolve some of the dependencies of the Router class.

navbar.component.ts

import { Router, ROUTER_DIRECTIVES } from '@angular/router';
import { Component } from '@angular/core';

@Component({
  moduleId: module.id,
  selector: 'navbar',
  templateUrl: 'navbar.component.html',
  styleUrls: ['navbar.component.css'],
  directives: [ROUTER_DIRECTIVES],
  providers: [Router],
})

I fixed this by not injecting Router as a provider, and only injecting into the constructor so you end up with:

@Component({
    moduleId: module.id,
    selector: 'navbar',
    templateUrl: 'navbar.component.html',
    styleUrls: ['navbar.component.css'],
    directives: [ROUTER_DIRECTIVES]
  })

  export class NavbarComponent
  {
    version: string;
    versionIsVisible: boolean;

    constructor(private _router: Router) {
      this.version = '<%= VERSION %>';
    }

    ngOnInit() {
      // ...
    }
}

I'm new to angular2 so I'm not able to give you a detailed reason why!

Answer 2

Here is some code from a personal project I have worked on using Angular 2 RC5 and that has routers working. I used the information straight from the documentation so maybe it will be helpful to you.

app.routing.ts

import { Routes, RouterModule } from '@angular/router';
import { HomeComponent } from '../home/home.component';
import { ApprovalsComponent } from '../approvals/approvals.component';

const appRoutes : Routes = [
{
path: 'Home', component: HomeComponent ,
data: { Title: 'Home'}
},
{
path: 'Approvals', component: ApprovalsComponent,
data: { Title: 'My Approvals'} 
}]


export const appRoutingProviders: any[] = [


];

export const routing = RouterModule.forRoot(appRoutes);

app.module.ts

import { NgModule }      from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { HttpModule } from '@angular/http'

import { AppComponent }  from './app.component';
import { HomeComponent } from '../home/home.component'
import { ApprovalsComponent } from '../approvals/approvals.component'
import { routing, appRoutingProviders } from './app.routing'

@NgModule({
   imports:      [ BrowserModule, routing, HttpModule, BrowserModule],
   declarations: [ AppComponent, HomeComponent, ApprovalsComponent],
   providers : [appRoutingProviders],
   bootstrap:    [ AppComponent ]
   })

 export class AppModule { }

html for routerlink

  <a [routerLink]="['Home']">
                    Home
                </a>

Do you have your router outlet declared somewhere? In my app.html I have:

 <router-outlet></router-outlet>