A lightweight, declarative and configurable breadcrumbs solution for Angular 6 and beyond. https://www.npmjs.com/package/my-xng

About

• In applications with deep navigation hierarchy, it is essential to have breadcrumbs.
• Breadcrumbs easily allow going back to states higher up in the hierarchy.

Demo

Live Demo - A demo app showcasing my-xng usage in an Angular app. Navigate through different links to see breadcrumbs behavior.

Features

• ✅ Zero configuration: Just add <my-xng></my-xng> anywhere in the app. Breadcrumb labels will be auto-generated by analyzing Angular Route configuration in your App.

• ✅ Custom labels: each route can have a custom label defined via Angular Route Config. The labels will be picked automatically while forming breadcrumbs

• ✅ Update labels dynamically: Change breadcrumbs dynamically using BreadcrumbService.set(). You can either use route path or breadcrumb alias to change breadcrumb for a route.

• ✅ Skip breadcrumb: Skip specific routes from displaying in breadcrumbs, conditionally.

• ✅ Disable breadcrumb: Disable specific routes so that navigation is disbaled to intermediate routes.

• ✅ Customization: Customize breadcrumb template to show icons as label prefix, use pipes on text, add i18n, etc.

• ✅ Styling: Separator and Styles can be customized with ease.

• ✅ QueryParams and Fragment: Preserves QueryParams and Fragemnet while navigating via breadcrumbs

Quickstart

1. Install via npm or yarn

npm install --save my-xng
//------------- OR --------------
yarn add my-xng

2. Import 'BreadcrumbModule' in your Application

import {BreadcrumbModule} from 'my-xng';
@NgModule({
  ...
  imports: [BreadcrumbModule],
  ...
})
export class AppModule { }

3. Add 'my-xng' selector, wherever you plan to show breadcrumbs

<my-xng></my-xng>

4. (Optional) Use BreadcrumbService, if you want to change breadcrumbs behavior(visibility, label, etc) dynamically.

import { BreadcrumbService } from 'my-xng';

constructor(private breadcrumbService: BreadcrumbService) {}
// Code examples with BreadcrumbService are given below, under Usage section

🎉🎉 That's it. You should see auto-generated breadcrumbs appearing for each route.

Note: XngBreadcrumb has a peer dependency on @angular/router. Include RouterModule in App imports, if you haven't already.

Angular Version Compatibility

| my-xng | Angular | | -------------- | -------------- | | 4.x.x | 6.x, 7.x | | 6.x.x | 8.x, 9.x, 10.x |

Setup Guide

Custom breadcrumb labels via Angular Route Config

• define 'breadcrumb' within the data property of route.
• a 'breadcrumb' can be defined as a string OR object OR function.
• Use breadcrumb as a string if you are just providing breadcrumb text
• Use breadcrumb as an object if you are providing additional properties like 'alias', 'skip', 'info', 'disable'. In you define breadcrumb as an object, label property denotes breadcrumb text.
• Use breadcrumb as a function if you want to alter the auto-generated label as needed.

breadcrumb as a string

  {
    path: 'dashboard',
    loadChildren: './dashboard/dashboard.module#DashboardModule',
    data: { breadcrumb: 'Home' }
  },
  {
    path: 'add',
    component: MentorAddComponent,
    data: { breadcrumb: 'New' }
  }

breadcrumb as an object

  {
    path: 'dashboard',
    loadChildren: './dashboard/dashboard.module#DashboardModule',
    data: {
      breadcrumb: {
        label: 'Home',
        info: { myData: { icon: 'home', iconType: 'material' } }
      }
    }
  },
  {
    path: 'add',
    component: MentorAddComponent,
    data: { breadcrumb: { skip: true, alias: 'mentorAdd' } }
  }

breadcrumb as a function

{
  path: '/orders',
  children: [{
    ':id',
    data: {
      breadcrumb: (resolvedId: string) => `Viewing ${resolvedId} now`
    }
  }]
}

Update labels dynamically

• Breadcrumb label can be updated dynamically using route path or alias
• For simple routes, route path is enough. Ex: breadcrumbService.set(<route path> , <breadcrumb label>)
• For long deep routes, you can use alias instead.
• Create an alias for a route in route config. Prefix alias with '@' while using the set() method. Ex: breadcrumbService.set(@<alias> , <breadcrumb label>)

using route path to update labels dynamically

  {
    path: 'mentors',
    component: MentorListComponent,
    children: [
      {
        path: ':id',
        component: MentorDetailsComponent
      }
    ]
  }

  // routepath can contain path params similar to how you define in routes
  breadcrumbService.set('mentors', 'Mentor View'); // path for MentorListComponent
  breadcrumbService.set('mentor/:id', 'Uday Vunnam'); // path for MentorDetailsComponent contains param (:id)

using alias to update labels dynamically

  {
    path: 'mentors',
    component: MentorListComponent,
    children: [
      {
        path: ':id',
          component: MentorDetailsComponent
          data: {
            breadcrumb: {
              alias: 'mentorName'
            }
          }
        }
    ]
  }

  breadcrumbService.set('@mentorName', 'Uday Vunnam');

Skip Breadcrumbs for certain route path

You can skip a route from displaying in breadcrumbs in two ways

• make skip: true in route config breadcrumb: { skip: true }
• dynamically skip using set(<myPathOrAlias>, { skip:true });

skip breadcrumb in route config

  {
    path: 'edit',
    component: MentorEditComponent,
    data: { breadcrumb: { skip: true } }
  }

skip breadcrumb dynamically

breadcrumbService.set('mentor/:id/edit', { skip: true });
breadcrumbService.set('@mentorName', { skip: true }); // using alias '@mentorName'

//To make a hidden breadcrumb visible.
breadcrumbService.set('mentor/:id/edit', { skip: false });
breadcrumbService.set('@mentorName', { skip: false }); // using alias '@mentorName'

Dibsable Breadcrumb navigation for certain routes

You can show an intermediate breadcrumb, but disable navigation if the route has no meaning.

• make disable: true in route config breadcrumb: { disable: true }
• dynamically skip using set(<myPathOrAlias>, { disable:true });

Customization

Custom Breadcrumb template (add icons, change text, add i18n ability, etc)

You can display whatever you want in the place of breadcrumb text by providing a custom template.

• Use *xngBreadcrumbItem directive to provide a custom template
• breadcrumb label is available implicitly in the template context

Change text case

  {
    path: '',
    pathMatch: 'full',
    component: HomeComponent,
    data: {
      breadcrumb: 'app home'
    }
  }

<my-xng>
  <ng-container *xngBreadcrumbItem="let breadcrumb">
    <ng-container>{{ breadcrumb | titlecase }}</ng-container>
  </ng-container>
</my-xng>

Add icons in front of label

• define 'info' associated with breadcrumb in route config. 'info' has type . you can pass string or object as you need.
• 'info' is available in the context of *xngBreadcrumbItem.
• Additionally 'first', 'last', 'index' and count are passed to identify the respective items.

  {
    path: '',
    pathMatch: 'full',
    component: HomeComponent,
    data: {
      breadcrumb: {
        label: 'app home',
        info: 'home'
      }
    }
  }

<my-xng>
  <ng-container
    *xngBreadcrumbItem="let breadcrumb; let info = info; let first = first"
  >
    <mat-icon *ngIf="info">{{ info }}</mat-icon>
    <ng-container *ngIf="!first">{{ breadcrumb }}</ng-container>
  </ng-container>
</my-xng>

Internationalization - i18n

• Usually, internationalization is achieved in Angular using libraries like ngx-translate or transloco.
• These libraries provide a pipe to change text while language is changed.
• For example, if you are using ngx-translate you can change the language for breadcrumb text as shown below.

<my-xng>
  <ng-container *xngBreadcrumbItem="let breadcrumb">
    <ng-container>{{ breadcrumb | translate }}</ng-container>
  </ng-container>
</my-xng>

Custom separator

• Breadcrumb uses '/' as the separator by default.
• To use custom separator pass separator as an input to <my-xng>.
• You can either use a simple string(>>, -, -->) or a component (mat-icon, fa-icon) as a separator.

string as separator

<my-xng separator=">"></my-xng>

icon or component as separator

<my-xng [separator]="iconTemplate"></my-xng>

<ng-template #iconTemplate>
  <mat-icon>arrow_right</mat-icon>
</ng-template>

Custom Breadcrumb Styles

• <my-xng> defines the least possible specificity for selectors, to make it easy to override them.

• override styles by changing the CSS for corresponding classes. (Keep this styles in app root styles file if you don't want to use ::ng-deep)

• Below is a visualization of various classes involved in my-xng to help you for easy identification.

• (Optional) my-xng takes 'class' as input. This class will be applied to the root of the breadcrumb. This can be used to increase specificity when there are conflicting styles.

  

.my-xng-root {
  padding: 8px 16px;
  display: inline-block;
  border-radius: 4px;
  background-color: #e7f1f1;
}

.my-xng-separator {
  padding: 0 4px;
}

Disable Auto Generation of breadcrumb labels

• Breadcrumbs are integrated with Angular Router and labels are auto-generated (if a label is not provided for a route).
• Auto-generated label is the same as route the path segment.
• If you want to disable this behavior, set [autoGenerate]=false.

<my-xng [autoGenerate]="false"></my-xng>

Intercept the routing via breadcrumb navigation - routeInterceptor

When we have conditional routing in App components (Ex: for a certain role navigate to pathA vs pathB from a component), it might be useful to have conditional routing from breadcrumb too

• With App's RouteConfig: Provide routeInterceptor callback in RouteConfig if you know the redirection logic upfront

  {
    path: '',
    pathMatch: 'full',
    component: HomeComponent,
    data: {
      breadcrumb: {
        label: 'my home',
        info: 'home',
        routeInterceptor: (routeLink, breadcrumb)=> {
          console.log(routeLink);
          return routeLink;
        }
      },
    },
  }

• With Breadcrumb service: If you want to access Application context within the interceptor, use breadcrumbService that can be called from anywhere in the App

const isDesigner = true;
breadcrumbService.set('home', {
  routeInterceptor: (routeLink, breadcrumb) =>
    isDesigner ? '/designer' : routeLink,
});

API

App Route Config -> data -> breadcrumb

| property | Description | Type | Default | | --------------------- | ---------------------------------------------------------------- | --------- | ----------- | | breadcrumb | Breadcrumb data provided in App route config | string | Breadcrumb | Function | undefined | | breadcrumb: {alias} | alias name for a route | string | undefined | | breadcrumb: {skip} | skip a route from showing in breadcrumbs | boolean | false | | breadcrumb: {disable} | disable navigation for a breadcrumb item | boolean | false | | breadcrumb: {info} | arbitrary info for a breadcrumb. | string | object | undefined | | breadcrumb: {label} | same as breadcrumb. Use label if breadcrumb is defined as object | string | undefined |

my-xng component

| Input | Description | Type | Default | | ------------------- | --------------------------------------------------------- | --------- | ------------------ | | separator | input: separator between breadcrumbs | string | TemplateRef<void> | / | | autoGenerate | input:whether to auto generate breadcrumb labels | boolean | true | | *xngBreadcrumbItem | directive: to read context in custom breadcrumb templates | NA | NA | | preserveQueryParams | preserve query params while navigating via breadcrumbs | boolean | true | | preserveFragment | preserve fragment while navigating via breadcrumbs | boolean | true |

BreadcrumbService.set(pathOrAlias, breadcrumb)

| argument | Description | Type | | ----------- | ------------------------------------------ | -------- | | pathOrAlias | full route path or alias prefixed with '@' | string | | breadcrumb | breadcrumb data to update for a route | string | Breadcrumb |

Where to define breadcrumbs, if Routes path have same Route specificity

• For the same route path, you can define breadcrumbs either on parent or any descendant with empty path.
• If both are defined, the children take the precedence.

With Component and its Children

  // defining breadcrumb on Component Route
  {
    path: ':userId',
    data: { breadcrumb: 'Declared on Parent Component' },
    children: [
      { path: '', component: ShowUserComponent }
    ]
  }
  // defining breadcrumb on children with empty path
  {
    path: ':userId',
    children: [
      { path: '', component: ShowUserComponent, data: { breadcrumb: 'Declaraed on child with empty path' }
    ]
  }

With Module and its Children

  // defining breadcrumb on Module route
  { path: 'home', loadChildren: './home/home.module#HomeModule', data: { breadcrumb: 'Declaraed on Parent Module' } }

  // Within HomeModule Routes -
  { path: '', pathMatch: 'full', component: HomeComponent, data: { breadcrumb: 'Declaraed on child with empty path' }}

Accessibility

• A <nav> with aria-label="breadcrumb" identifies type of navigation as breadcrumb by screen readers.
• The breadcrumb links are structured using an ordered list <ol>.
• The last <li> element represents the current page, so it doesn't have to be clickable.
• Separators between links have aria-hidden=true. This prevents the screen reader announcement of visual separators.

Local Development

This project was generated using Nx.

If you wish to contribute to this repository, below are the steps for local development.

• Clone the repository git clone https://github.com/udayvunnam/my-xng.git
• Run yarn to install the dependencies
• Run yarn start to build and watch both the library and the demo app. This opens the demo app at http://localhost:4200/ automatically.

Build

Run yarn build to build the library and demo app together. The build artifacts will be stored in the dist/ directory.

This step is used by CircleCI to build both the library and the demo app. After a successful build, the two demo apps are deployed to Netlify.

Publish to npm

Run yarn release on main branch if you wish to publish a new version of library to npm

This ingternally uses standard-version to

• bump the library version based on the commits
• generates changelog
• commit bump files and changelog
• create a new tag with the new version number

CircleCI gets notified on every new tag push and publishes the library if build and tests are success

Tests

• Unit tests: yarn test to execute the unit tests via Jest
• e2e: yarn e2e to execute the e2e tests via Cypress.io

Motivation 🎉🎉🎉

You can create your library with complete automated setup for build, tests, and release. Check this blog post for best practices and implementation details of this library blog post