PP-Breadcrumbs

PP-Breadcrumbs is an Angular 7 module generating breadcrumbs based on the routing state.

Demo: Stackblitz

Installation

Install via npm:

npm install pp-breadcrumbs --save 

Once you installed, you need to import the module:

import { PpBreadcrumbsModule } from 'pp-breadcrumbs';

@NgModule({
  ...
  imports: [PpBreadcrumbsModule, ...],
  ...
})
export class AppModule {
}

Usage

Use the pp-breadcrumbs component to render the breadcrumbs:

@Component({
  selector: 'app-root',
  template: `
    <div class="container">
      <pp-breadcrumbs></pp-breadcrumbs>
      <router-outlet></router-outlet>
    </div>`
})
export class AppComponent {}

Rendering with pp-breadcrumbs is optional, and uses Bootstrap 4 CSS classes. If a different markup output is desired, a custom component can be created that subscribes to the PpBreadcrumbsService.crumbs$ observable.

Routing Configuration

Breadcrumb links are generated based on the route configuration. If a route entry contains a data.breadcrumbs property the breadcrumbs service assumes breadcrumbs should be created whenever this route or one its child routes are active.

const routes: Routes = [
  {
    path: 'items',
    // Uses static text (Items)
    data: { breadcrumbs: 'Items' },
    children: [
      { path: '', component: ListComponent },
      {
        path: ':id',
        // Interpolates values resolved by the router
        data: { breadcrumbs: '{{ item.name }}' },
        resolve: { item: ItemResolver },
        children: [
          { path: '', component: ItemComponent },
          { path: 'subitem', component: SubitemComponent, data: { breadcrumbs: `<i class="fas fa-user"></i> Subitem` } }
        ]
      }
    ]
  },
  {
    path: 'another-items',
    // Uses last urlfragment (another-items) as text
    data: { breadcrumbs: true },
    children: [
      { path: '', component: ListComponent },
      {
        path: ':id',
        // Resolves the breadcrumbs for this route by extending the PpBreadcrumbsResolver class.
        data: { breadcrumbs: AnotherItemResolver },
        children: [
          { path: '', component: ItemComponent },
          { path: 'subitem', component: SubitemComponent, data: { breadcrumbs: 'Subitem' } }
        ]
      }
    ]
  },
];

API reference

Breadcrumb

Represents a breadcrumb. HTML content in the text property is allowed.

export interface Breadcrumb {
  text: string;
  path: string;
}

PpBreadcrumbsComponent

Selector: [pp-breadcrumbs]

Renders the Breadcrumb[] provided by the PpBreadcrumbsService. The HTML output is based on the Bootstrap 4 breadcrumbs.

Properties

Name	Description
crumbs: Breadcrumb[]	Actually rendered breadcrumbs

PpBreadcrumbsService

Properties

Name	Description
crumbs$: Observable<Breadcrumb[]>	Observable stream of Breadcrumb[], which is updated after each route change
postProcess: (crumbs: Breadcrumb[]) => Promise<Breadcrumb[]> | Observable<Breadcrumb[]> | Breadcrumb[]	Callback function, which allows to modify the fully created breadcrumbs
refreshBreadcrumbs: () => void	Function to refresh breadcrumbs. postProcess() is applied to last version of breadcrumbs(before postProcess)

PpBreadcrumbsResolver

Resolving Breadcrumb[] from the route, PpBreadcrumbsService uses this resolver by default. There are two ways to resolve breadcrumbs:

• use a resolver, which implements the Resolve<T> (regular resolver), and use like this:

  const routes: Routes = [
    ..
    { path: ':id', data: { breadcrumbs: '{{ item.name }}' }, resolve: { item: ItemResolver } },
    ..
  ];
  

• use a resolver, which extends from PpBreadcrumbsResolver and return the created breadcrumb. Then use like this:

  const routes: Routes = [
    ..
    { path: ':id', data: { breadcrumbs: AnotherItemResolver } },
    ..
  ];
  

You can see examples for both ways in the demo app.

Methods

Name	Description
resolve(route: ActivatedRouteSnapshot, state: RouterStateSnapshot): Observable<Breadcrumb[]> | Promise<Breadcrumb[]> | Breadcrumb[]	Resolve function to create custom breadcrumbs for the given routes
getFullPath(route: ActivatedRouteSnapshot): string	Returns the full path for the provided route snapshot