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How to access queryParams in a Resolver Angular

I Need to implement 'search' by passing queryParams through route from the search component to the userList component (example. /search-result?user="Alfred"). Before loading the userList component, i need to make an API call using the queryParams in the userList resolver but the query params keeps showing undefined.
Search Component
search(searchTerm: string) {
if (searchTerm) {
this.router.navigate(['search-result'], { queryParams: { user: searchTerm } });
}
}
UserList Resolver
export class UserResolver implements Resolve<User[]> {
constructor(private userService: UserService, private route: ActivatedRoute) { }
resolve(): Observable<User[]> {
const searchTerm: string = this.route.snapshot.queryParams['user'];
console.log(searchTerm); //Logs Undefined
return this.userService.getUsers(searchTerm);
}
}

On latest versions of Angular you can get the ActivatedRouteSnapshot on the resolver function.
export class UserResolver implements Resolve<User[]> {
constructor(private userService: UserService, private route: ActivatedRoute) { }
resolve(**route: ActivatedRouteSnapshot**): Observable<User[]> {
**console.log(route.queryParams)**
return this.userService.getUsers(searchTerm);
}
}

Maybe the resolve function is running before the queryParams are populated in the url. Try doing it in an Rxjs way.
import { filter, map, switchMap, tap } from 'rxjs/operators';
...
export class UserResolver implements Resolve<User[]> {
constructor(private userService: UserService, private route: ActivatedRoute) { }
resolve(): Observable<User[]> {
return this.route.queryParams.pipe(
tap(params => console.log(`Params: ${params}`)),
// wait until params has user in it
filter(params => !!params['user']),
tap(params => console.log('after filter')),
// extract the value of the user param
map(params => params['user']),
// switch to a new observable stream once we know the searchTerm
switchMap(searchTerm => this.userService.getUsers(searchTerm)),
);
}
}
Edit
Use the tap operator to debug the stream. See what the log is and make sure console.log(Params: ${params}) has the user params.
Edit2
Try
this.router.navigateByUrl(`/search-result?user=${searchTerm}`);
, I am thinking there is something wrong with how you navigate.
Edit 3
I am thinking queryParams can only be read when the component itself loads and not at the run time of the route resolvers because it is saying, I need to go to the route of search-result, give me the data before I go to search-result and it is independent of the queryParams. To fix this, I followed this guide (https://blog.thoughtram.io/angular/2016/10/10/resolving-route-data-in-angular-2.html).
1.) In app-routing-module.ts, change the registration of the path to:
{ path: 'search-result/:user', component: UserListComponent, resolve: { users: UserResolver } },
Now the user will be the parameter we are after in the URL.
2.) In search.component.ts, change search to:
search(searchTerm: string) {
if (searchTerm) {
this.router.navigate([`search-result/${searchTerm}`]);
}
}
3.) In user-resolver.service.ts, change it to this:
#Injectable({
providedIn: 'root'
})
export class UserResolver implements Resolve<User[]> {
constructor(private userService: UserService) { }
resolve(route: ActivatedRouteSnapshot): Observable<User[]> {
const searchTerm: string = route.paramMap.get('user');
return this.userService.getUsers(searchTerm);
}
}
I when console logging searchTerm, it is the accurate value. Thanks for providing the StackBlitz, it helped you and me.

Navigate in Angular 7 without adding parameter to URL

I want to navigate between two routes in Angular 7 with posting data between them. But I don;t want to show those parameter in URL. How to do it in proper way?
at this moment I am strugging with something like this:
this.router.navigate(['/my-new-route', {data1: 'test', test2: 2323, test: 'AAAAAAA'}]);
and it change my url to
http://localhost:4200/my-new-route;data1=test;test2=2323;test=AAAAAAA
how to do it to cancel those data from url:
http://localhost:4200/my-new-route
Edit:
My case:
/form - route with some form
/options - route with some data
on /form route - users have some form with empty fields to fill manually
but on /options page there is some preset configuration, when user choose one is navigated to /form and fields are fill autmatically
when they move back to another page and back again to /form - should see empty form. Only link from /options to /form should fill those fields.

You can create a service and share it between both the components (the one that you're moving from, and the one that you're moving to).
Declare all the parameters that you want to pass to the URL, in the service, and before the router.navigate([]), set the values for parameters in the service.
You can access those parameters from the other component with that service.
Example:
SharedService
import { Injectable } from '#angular/core';
#Injectable({
providedIn: 'root'
})
export class SharedService {
data1;
test2;
test;
}
Component1
import { SharedService } from 'location';
import { Router } from '#angular/router';
...
constructor(private _sharedService: SharedService,
private _router: Router) { }
...
this._sharedService.data1 = 'test'
this._sharedService.test2 = 2323;
this._sharedService.test = 'AAAAAAAA';
this._router.navigate(['/my-new-route']);
...
Component2
import { SharedService } from 'location';
...
private test2;
private test;
private data1;
constructor(private _sharedService: SharedService){ }
ngOnInit() {
this.data1 = this._sharedService.data1;
this.test2 = this._sharedService.test2;
this.test = this._sharedService.test;
...
}

There are few ways to do it.
Try 1 :
this.router.navigate(['/some-url'], { queryParams: filter, skipLocationChange: true});
Try 2 :
We can use this work around instead by using EventEmitter and BehaviorSubject with a shared service
In component 1:
this.router.navigate(['url']).then(()=>
this.service.emmiter.emit(data)
)
In service :
emmiter : EventEmitter = new EventEmitter();
In component 2: inside constructor
this.service.emmiter.subscribe();

another solution for passing information from one route to another without touching the query params is via the state field of NavigationExtras (as of Angular 7.2+)
something along these lines
// Publish
<a
[routerLink]="['/studies', study.id]"
[state]="{ highlight: true }">
{{study.title}}
</a>
// Subscribe
constructor(private route: ActivatedRoute, ...) {
}
public highlight: boolean;
public ngOnInit() {
...
this.route.paramMap
.pipe(map(() => window.history.state))
.subscribe(state => {
this.highlight = state && state.highlight;
});
...
}
// Alternative
constructor(private router: Router, ...) {
}
public highlight: boolean;
public ngOnInit() {
...
this.router.events.pipe(
filter(e => e instanceof NavigationStart),
map(() => this.router.getCurrentNavigation().extras.state)
)
.subscribe(state => {
this.highlight = state && state.highlight;
})
...
}

pass value through "state" key from which you want to naviagte to next component:
//From where we Navigate
import {ActivatedRoute, NavigationExtras, Router} from "#angular/router";
export class MainPageComponent {
constructor(public router:Router) {}
navWithExtraValue () {
const navigationExtras: NavigationExtras = {
state: {
editMode: true
},
};
}
}
//In constructor where we Navigated
constructor(public router:Router,
public route:ActivatedRoute){
this.route.queryParams.subscribe(data=> {
if (this.router.getCurrentNavigation().extras.state) {
this.editMode = this.router.getCurrentNavigation().extras.state.editMode;
}
});
We don't see these value in url

Need help accessing variable from Service in Angular 2

Passing the URL id from the last page a user was on to a service that I can reference in a dialog.
issuer.service.ts
import { Injectable, EventEmitter } from '#angular/core';
import { Observable, of } from 'rxjs';
import { BehaviorSubject } from 'rxjs';
#Injectable()
export class IssuerService {
private urlidSource = new BehaviorSubject<string>('');
currentUrlid = this.urlidSource.asObservable();
public onChange: EventEmitter<string> = new EventEmitter<string>();
constructor () {
}
changeUrlid(urlid: string) {
this.currentUrlid = of(urlid);
this.onChange.emit(urlid);
}
getUrlid(currentUrlid: string) {
return this.currentUrlid;
}
}
Page that has the URL id I want (dashboard.component.ts)
import { IssuerService } from './../../issuer.service';
import { ActivatedRoute } from '#angular/router';
import { Router } from '#angular/router';
urlid: string;
constructor(
private route: ActivatedRoute,
private router: Router,
private issuerService: IssuerService,
public dialog: MatDialog
) {}
newUrlid() {
this.issuerService.changeUrlid(this.route.snapshot.paramMap.get('id'));
console.log(this.urlid);
}
ngOnInit() {
// Get URL ID
this.issuerService.onChange.subscribe(urlid => this.urlid = urlid);
this.newUrlid();
}
Component I want to read the value in:
import { ActivatedRoute } from '#angular/router';
import { Router } from '#angular/router';
import { IssuerService } from './../../issuer.service';
urlid: string;
constructor(
private route: ActivatedRoute,
private router: Router,
private issuerService: IssuerService,
public dialog: MatDialog
) {}
ngOnInit() {
this.issuerService.onChange.subscribe(urlid => {
this.urlid = urlid;
console.log(this.urlid);
});
}
So currently when I visit my dashboard page it will display the value of 2 which is correct. My goal is that when a user visits any page I can read this value of 2. How can I access this value? The above code works and my Header displays 2 but only when on the dashboard page. I need it to display 2 no matter what page the user is on.

you can see this example, and It's modified list:
use queryPamas to get query string, not params (DashboardComponent)
use ReplaySubject(1) to return the last urlId; it's don't have a default value, just return prev one value (IssuerService)
get observable from getUrlid and subscribe it in components that want to show url id
export class IssuerService {
private urlidSource = new ReplaySubject<string>(1);
constructor() {
}
changeUrlid(urlid: string) {
this.urlidSource.next(urlid);
}
getUrlid() {
return this.urlidSource;
}
}
export class DashboardComponent implements OnInit {
urlid: string;
constructor(
// private route: ActivatedRoute,
private router: Router,
private issuerService: IssuerService,
// public dialog: MatDialog
) { }
newUrlid() {
// Get URL ID
this.route.queryParams.subscribe((queryParam) => {
const id = queryParam['id'];
if (!id) {
return;
}
this.issuerService.changeUrlid(id);
});
}
ngOnInit() {
this.newUrlid();
this.issuerService.getUrlid().subscribe(urlid => {
this.urlid = urlid;
});
}
}
export class HelloComponent implements OnInit {
urlid;
constructor(
private issuerService: IssuerService
) { }
ngOnInit() {
this.issuerService.getUrlid().subscribe(urlid => {
this.urlid = urlid;
});
}
}

You do not need a parameter for your get Method since you already have the value inside the service,
getUrlid() {
return this.currentUrlid;
}
and you can use retrieve the value in the 2nd component as follows,
this.issuerService.currentUrlid.subscribe((value: string) => {
this.urlid = value;
}

Angular 2 shared service to pass data to component-to-component

I am trying to pass the string value of this.title from my LandingPage.component to my ResultPage.component.
I retrieve the list.show value, and send it to my TitleService in like so in my:
landingpage.component.html
<ol>
<li (click)="selectShow(list.show)" [routerLink]="['/details', list.id]" *ngFor="let list of shows">{{list.show}}
</li>
</ol>
landingpage.component.ts
import { TitleService } from '../../services/title.service';
constructor(private TitleService: TitleService) {}
selectShow(show) {
this.TitleService.fetchTitle(show)
}
The above sends the list.show value to my:
title.service.ts
// this gives us the name of the clicked show, which we send to TitleResolver
#Injectable()
export class TitleService {
fetchTitle(title) {
console.log("title is " + title); // this outputs correctly
return title;
}
}
And here is how I manage the routing in my:
app-routing.module.ts
import { TitleService } from './services/title.service';
const routes: Routes = [
{ path: '', component: LandingPage },
{
path: 'details/:id', component: ResultPage
}
];
#NgModule({
imports: [RouterModule.forRoot(routes)],
exports: [RouterModule],
providers: [TitleService]
})
My question
Once I receive the title.show value in my service component, I'm unsure how to then send it to my receiving component (resultpage.component)
How can I send my title value from my service to my ResultPage.component?

Make the title a public property of the service like this:
// this gives us the name of the clicked show, which we send to TitleResolver
#Injectable()
export class TitleService {
selectedTitle: string;
fetchTitle(title) {
console.log("title is " + title); // this outputs correctly
this.selectedTitle = title;
return title; // No need to return it.
}
}
Then any other component can inject this service and access this.titleService.selectedTitle

In title.service.ts you can declare a variable called title and have setter and getter:
title: string ="";
// replace fetchTitle with setTitle
// remember to change it in the component too
setTitle(title) {
this.title = title;
}
getTitle() {
return this.title;
}
Then, when ResultPage.component is initialized, call getTitle() from TitleService and set the result to a variable declared in the component.
Here's an example of sharing data via shared services.

Separation of concerns... Your landing page is used to select the list item and navigate to the result page. Let it do just that and only that. Let the ResultPage.component do the rest. Note: Other answers recommend storing the value of the last title in the TitleService. It's not a good idea to store state in a service. Then TitleService cannot be used as a generic way to get any title separate from your current navigation, without side effects.
Remove (click) event. Add 'show' as a QueryParam.
landingpage.component.html
<li [routerLink]="['/details', list.id]"
[queryParams]="{show: list.show}"
*ngFor="let list of shows">
{{list.show}}
</li>
Subscribe to router params and queryparams to get the id and show.
resultpage.component.ts
import { Component, OnInit, OnDestroy } from '#angular/core';
import { ActivatedRoute, Router } from '#angular/router';
import { TitleService } from '../../services/title.service';
#Component({
...
})
export class ResultPageComponent implements OnInit, OnDestroy {
itemId: string;
show: string;
subParams: any; // infinite Observable to be unsubscribed
subQueryParams: any; // infinite Observable to be unsubscribed
constructor(
...
private TitleService: TitleService,
protected route: ActivatedRoute,
protected router: Router,
...
) {}
ngOnInit() {
this.subParams = this.route.params.subscribe(this.onParams);
this.subQueryParams = this.route.queryParams(this.onQueryParams);
}
ngOnDestroy() {
// Delete active subscribes on destroy
this.subParams.unsubscribe();
this.subQueryParams.unsubscribe();
}
onParams = (params: any) => {
this.itemId = params['id'];
}
onQueryParams = (data: any) => {
this.show = data.show;
if(this.show) {
this.TitleService.fetchTitle(this.show)
}
}

How to handle query parameters in angular 2

In my routable component I have
#RouteConfig {
{path: '/login', name: 'Login', component: LoginComponent}
}
But how do I get the query params if I go to app_url/login?token=1234?

RouteParams are now deprecated , So here is how to do it in the new router.
this.router.navigate(['/login'],{ queryParams: { token:'1234'}})
And then in the login component you can take the parameter,
constructor(private route: ActivatedRoute) {}
ngOnInit() {
// Capture the token if available
this.sessionId = this.route.queryParams['token']
}
Here is the documentation

To complement the two previous answers, Angular2 supports both query parameters and path variables within routing. In #RouteConfig definition, if you define parameters within a path, Angular2 handles them as path variables and as query parameters if not.
Let's take a sample:
#RouteConfig([
{ path: '/:id', component: DetailsComponent, name: 'Details'}
])
If you call the navigate method of the router like this:
this.router.navigate( [
'Details', { id: 'companyId', param1: 'value1'
}]);
You will have the following address: /companyId?param1=value1. The way to get parameters is the same for both, query parameters and path variables. The difference between them is that path variables can be seen as mandatory parameters and query parameters as optional ones.
Hope it helps you,
Thierry
UPDATE: After changes in router alpha.31 http query params no longer work (Matrix params #2774). Instead angular router uses so called Matrix URL notation.
Reference https://angular.io/docs/ts/latest/guide/router.html#!#optional-route-parameters:
The optional route parameters are not separated by "?" and "&" as they
would be in the URL query string. They are separated by semicolons ";"
This is matrix URL notation — something you may not have seen before.

It seems that RouteParams no longer exists, and is replaced by ActivatedRoute. ActivatedRoute gives us access to the matrix URL notation Parameters. If we want to get Query string ? paramaters we need to use Router.RouterState. The traditional query string paramaters are persisted across routing, which may not be the desired result. Preserving the fragment is now optional in router 3.0.0-rc.1.
import { Router, ActivatedRoute } from '#angular/router';
#Component ({...})
export class paramaterDemo {
private queryParamaterValue: string;
private matrixParamaterValue: string;
private querySub: any;
private matrixSub: any;
constructor(private router: Router, private route: ActivatedRoute) { }
ngOnInit() {
this.router.routerState.snapshot.queryParams["queryParamaterName"];
this.querySub = this.router.routerState.queryParams.subscribe(queryParams =>
this.queryParamaterValue = queryParams["queryParameterName"];
);
this.route.snapshot.params["matrixParameterName"];
this.route.params.subscribe(matrixParams =>
this.matrixParamterValue = matrixParams["matrixParameterName"];
);
}
ngOnDestroy() {
if (this.querySub) {
this.querySub.unsubscribe();
}
if (this.matrixSub) {
this.matrixSub.unsubscribe();
}
}
}
We should be able to manipulate the ? notation upon navigation, as well as the ; notation, but I only gotten the matrix notation to work yet. The plnker that is attached to the latest router documentation shows it should look like this.
let sessionId = 123456789;
let navigationExtras = {
queryParams: { 'session_id': sessionId },
fragment: 'anchor'
};
// Navigate to the login page with extras
this.router.navigate(['/login'], navigationExtras);

This worked for me (as of Angular 2.1.0):
constructor(private route: ActivatedRoute) {}
ngOnInit() {
// Capture the token if available
this.sessionId = this.route.snapshot.queryParams['token']
}

(For Childs Route Only such as /hello-world)
In the case you would like to make this kind of call :
/hello-world?foo=bar&fruit=banana
Angular2 doesn't use ? nor & but ; instead. So the correct URL should be :
/hello-world;foo=bar;fruit=banana
And to get those data :
import { Router, ActivatedRoute, Params } from '#angular/router';
private foo: string;
private fruit: string;
constructor(
private route: ActivatedRoute,
private router: Router
) {}
ngOnInit() {
this.route.params.forEach((params: Params) => {
this.foo = params['foo'];
this.fruit = params['fruit'];
});
console.log(this.foo, this.fruit); // you should get your parameters here
}
Source : https://angular.io/docs/ts/latest/guide/router.html

Angular2 v2.1.0 (stable):
The ActivatedRoute provides an observable one can subscribe.
constructor(
private route: ActivatedRoute
) { }
this.route.params.subscribe(params => {
let value = params[key];
});
This triggers everytime the route gets updated, as well: /home/files/123 -> /home/files/321

The simple way to do that in Angular 7+ is to:
Define a path in your ?-routing.module.ts
{ path: '/yourpage', component: component-name }
Import the ActivateRoute and Router module in your component and inject them in the constructor
contructor(private route: ActivateRoute, private router: Router){ ... }
Subscribe the ActivateRoute to the ngOnInit
ngOnInit() {
this.route.queryParams.subscribe(params => {
console.log(params);
// {page: '2' }
})
}
Provide it to a link:
<a [routerLink]="['/yourpage']" [queryParams]="{ page: 2 }">2</a>

Angular 4:
I have included JS (for OG's) and TS versions below.
.html
<a [routerLink]="['/search', { tag: 'fish' } ]">A link</a>
In the above I am using the link parameter array see sources below for more information.
routing.js
(function(app) {
app.routing = ng.router.RouterModule.forRoot([
{ path: '', component: indexComponent },
{ path: 'search', component: searchComponent }
]);
})(window.app || (window.app = {}));
searchComponent.js
(function(app) {
app.searchComponent =
ng.core.Component({
selector: 'search',
templateUrl: 'view/search.html'
})
.Class({
constructor: [ ng.router.Router, ng.router.ActivatedRoute, function(router, activatedRoute) {
// Pull out the params with activatedRoute...
console.log(' params', activatedRoute.snapshot.params);
// Object {tag: "fish"}
}]
}
});
})(window.app || (window.app = {}));
routing.ts (excerpt)
const appRoutes: Routes = [
{ path: '', component: IndexComponent },
{ path: 'search', component: SearchComponent }
];
#NgModule({
imports: [
RouterModule.forRoot(appRoutes)
// other imports here
],
...
})
export class AppModule { }
searchComponent.ts
import 'rxjs/add/operator/switchMap';
import { OnInit } from '#angular/core';
import { Router, ActivatedRoute, Params } from '#angular/router';
export class SearchComponent implements OnInit {
constructor(
private route: ActivatedRoute,
private router: Router
) {}
ngOnInit() {
this.route.params
.switchMap((params: Params) => doSomething(params['tag']))
}
More infos:
"Link Parameter Array"
https://angular.io/docs/ts/latest/guide/router.html#!#link-parameters-array
"Activated Route - the one stop shop for route info" https://angular.io/docs/ts/latest/guide/router.html#!#activated-route

For Angular 4
Url:
http://example.com/company/100
Router Path :
const routes: Routes = [
{ path: 'company/:companyId', component: CompanyDetailsComponent},
]
Component:
#Component({
selector: 'company-details',
templateUrl: './company.details.component.html',
styleUrls: ['./company.component.css']
})
export class CompanyDetailsComponent{
companyId: string;
constructor(private router: Router, private route: ActivatedRoute) {
this.route.params.subscribe(params => {
this.companyId = params.companyId;
console.log('companyId :'+this.companyId);
});
}
}
Console Output:
companyId : 100

According to Angular2 documentation you should use:
#RouteConfig([
{path: '/login/:token', name: 'Login', component: LoginComponent},
])
#Component({ template: 'login: {{token}}' })
class LoginComponent{
token: string;
constructor(params: RouteParams) {
this.token = params.get('token');
}
}

Angular 5+ Update
The route.snapshot provides the initial value of the route parameter
map. You can access the parameters directly without subscribing or
adding observable operators. It's much simpler to write and read:
Quote from the Angular Docs
To break it down for you, here is how to do it with the new router:
this.router.navigate(['/login'], { queryParams: { token:'1234'} });
And then in the login component (notice the new .snapshot added):
constructor(private route: ActivatedRoute) {}
ngOnInit() {
this.sessionId = this.route.snapshot.queryParams['token']
}

In Angular 6, I found this simpler way:
navigate(["/yourpage", { "someParamName": "paramValue"}]);
Then in the constructor or in ngInit you can directly use:
let value = this.route.snapshot.params.someParamName;