The Angular allows us to pass data to the route. The data can be static or dynamic. The static data use the Angular route data property, where you can store arbitrary data associated with this specific route. For to pass dynamic data (or an object), we can make use of the history state object. The Routed Component can then retrieve the dynamic data from the history state object.
Applies to: Angular 2, Angular 4, Angular 5, Angular 6, Angular 7, Angular 8
Various ways of passing data to route
The Angular can pass data to Route in several ways.
- Using URL or Route Parameter
- The Optional Parameter or Query Strings
- Using URL Fragment
- Static data using the data property
- Dynamic data using state object
Passing static data to a route
The static data is configured at the time of configuring the route. This is done by using the Angular route data property of the route. The route data property can contain an array of arbitrary string key-value pairs. The static data can be used to store items such as page titles, breadcrumb text, and other read-only, static data
For Example, consider the following route with the data property set
{ path: 'static', component: StaticComponent, data :{ id:'1', name:"Angular"}},The Angular Router will pass the { id:'1', name:"Angular"} when the StaticComponent is rendered. The data value will be located in the data property of the ActivatedRoute service
We can then read the data by subscribing to the activatedroute.data property as shown below
ngOnInit() {
this.activatedroute.data.subscribe(data => {
this.product=data;
})
}Passing Dynamic data to a Route
The option to pass the dynamic data or a user-defined object was added in the Angular Version 7.2 using the state object. The state object is stored in History API
Providing the State value
The state can be provided in two ways
Using routerLink directive
<a [routerLink]="['dynamic']" [state]="{ id:1 , name:'Angular'}">Dynamic Data</a>this.router.navigateByUrl('/dynamic', { state: { id:1 , name:'Angular' } });The Router will add a navigationId property to the state object. Hence you cannot use a scalar value.
Accessing the state value
The state can be accessed by using the getCurrentNavigation method of the router (works only in the constructor)
this.router.getCurrentNavigation().extras.stateOr use the history.state in the ngOnInit.
console.log(history.state)or use the getState method of the Location Service. This method is available Angular 8+
import { Location } from '@angular/common';
export class SomeComponent
{
products:Product[];
constructor(private location:Location){
}
ngOnInit() {
console.log(this.location.getState());
}
}Passing Data to the Routes Example
Let us build a simple project to demonstrate how to pass data to the route
Passing static data example
static.component.ts
import {Component, OnInit} from '@angular/core';
import { ActivatedRoute } from '@angular/router';
@Component({
template: `<h1>Passing Static Data Demo</h1>
{{product | json}}`
})
export class StaticComponent implements OnInit {
product:any;
constructor(private activatedroute:ActivatedRoute) {
}
ngOnInit() {
this.activatedroute.data.subscribe(data => {
this.product=data;
})
}
}The static component gets the static data configured in the route. It subscribes the activatedroute.data property to get the product data as shown above
Passing dynamic data (or object) example
dynamic.component.ts
import {Component, OnInit, ChangeDetectorRef} from '@angular/core';
import { ActivatedRoute, Router, NavigationStart } from '@angular/router';
import { map, filter} from 'rxjs/operators';
import { Observable} from 'rxjs/observable';
@Component({
template: `<H1>Passing Dynamic Data Demo</H1>
{{ product | json }}`
})
export class DynamicComponent implements OnInit {
product;
constructor(private router:Router, private activatedRoute:ActivatedRoute) {
console.log(this.router.getCurrentNavigation().extras.state);
}
ngOnInit() {
//console.log(history.state);
this.product=history.state;
}
}The Dynamic Component gets dynamic data. We use the history.state to access the product data. Alternatively, we can use the this.router.getCurrentNavigation().extras.state to achieve the same. Please remember getCurrentNavigation only works in the constructor. It will return null if used elsewhere.
home.component.ts
import { Component } from '@angular/core';
import { ActivatedRoute, Router } from '@angular/router';
@Component({
template: `
<ul>
<li><a [routerLink]="['/static']">Static Data</a></li>
<li><a [routerLink]="['/dynamic']" [state]=product>Dynamic Data</a></li>
</ul>
<p>Id : <input type="text" [(ngModel)]="product.id" > </p>
<p>name :<input type="text" [(ngModel)]="product.name" > </p>
<button (click)="gotoDynamic()" >Goto Dynamic Component</button>`
})
export class HomeComponent {
public product = { id:'1', name:"Angular"};
constructor(private router : Router) {
}
gotoDynamic() {
//this.router.navigateByUrl('/dynamic', { state: { id:1 , name:'Angular' } });
this.router.navigateByUrl('/dynamic', { state: this.product });
}
}In HomeComponent, we have used routerLink & navigateByUrl to pass the data to the dynamic component. You can also use the form fields to change the data, before passing it to the dynamic route.
app.routes.ts
import { Routes } from '@angular/router';
import { StaticComponent} from './static.component'
import { DynamicComponent } from './dynamic.component';
import { HomeComponent } from './home.component';
export const appRoutes: Routes = [
{ path: 'home', component: HomeComponent },
{ path: 'static', component: StaticComponent, data :{ id:'1', name:"Angular"}},
{ path: 'dynamic', component: DynamicComponent },
{ path: '', redirectTo: 'home', pathMatch: 'full' }
];
Here the static data is set for StaticComponent using the data property.
app.component.ts
import { Component } from '@angular/core';
@Component({
selector: 'app-root',
template: `<div class="container">
<nav class="navbar navbar-default">
<div class="container-fluid">
<div class="navbar-header">
<a class="navbar-brand" [routerLink]="['/']"><strong> {{title}} </strong></a>
</div>
</div>
</nav>
<router-outlet></router-outlet>
</div>`
})
export class AppComponent {
title = 'Routing Module - Passing Dynamic / Static data route';
}app.module.ts
import { BrowserModule } from '@angular/platform-browser';
import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { HttpModule } from '@angular/http';
import { RouterModule } from '@angular/router';
import { AppComponent } from './app.component';
import { StaticComponent} from './static.component'
import { appRoutes } from './app.routes';
import { DynamicComponent } from './dynamic.component';
import { HomeComponent } from './home.component';
@NgModule({
declarations: [
AppComponent,StaticComponent,DynamicComponent,HomeComponent
],
imports: [
BrowserModule,
FormsModule,
HttpModule,
RouterModule.forRoot(appRoutes)
],
providers: [],
bootstrap: [AppComponent]
})
export class AppModule { }
great