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ReplaySubject it is not updating the array when new object is added Angular

I am dealing with an error which when I try to create new page Object, it send to backend but it is not updating the array, I need to reload the page to see the all the array.
I am using Observable within async in the frontend.
I tried to console.log the ngOnInit of the page.component.ts but when I add new page and navigate to pages then the ngOnInit it isn't calling.
On Create new page it happens this.
It sends me to the route of pages where there I show all the list of pages.
But when I create new Page it is returningback an error which says.
ERROR Error: Error trying to diff 'Here is the name of the object'. Only arrays and iterables are allowed.
Update: as Marco said this happens because I mix page as Object instead I am iterating through array
But I am unable to resolve it and i need your help.
In the page.service.ts at pageModel when I add new Object it is returning me only the added Object not the whole array and there is the problem I think, but I don't know how to fix.
But If I reload page then I see all my Array.
This is my updated code.
This is my code.
export class PagesService {
public baseUrl = environment.backend;
private data = new ReplaySubject<any>();
public userID = this.authService.userID;
public editDataDetails: any = [];
public subject = new Subject<any>();
private messageSource = new BehaviorSubject(this.editDataDetails);
getPageID = this.messageSource.asObservable();
constructor(private http: HttpClient, private authService: AuthService) { }
public getPages() {
return this.http.get<any>(`${this.baseUrl}/pages/${this.userID}`).subscribe(res => this.data.next(res));
}
public pageModel(): Observable<Page[]> {
return this.data.asObservable(); // Here it throws error
}
public getPage(id): Observable<any> {
return this.http.get(`${this.baseUrl}/page/${id}`);
}
public setPage(page: Page, id: string) {
const api = `${this.baseUrl}/page`;
const user_id = id;
this.http.post<any>(api, page, {
headers: { user_id }
}).subscribe(res => this.data.next(res));
}
changeMessage(message: string) {
this.messageSource.next(message)
}
public updateDate(id: string, page: Page) {
const api = `${this.baseUrl}/page/${id}`;
return this.http.put<any>(api, page).subscribe(res => this.data.next(res.data));
}
Updated Code from Answer.
public updateDate(id: string, page: Page) {
const api = `${this.baseUrl}/page/${id}`;
return this.http.put<any>(api, page).subscribe(res => {
this.lastSetOfData = res;
this.data.next(this.lastSetOfData);
});
}
}
export class Page {
_id = "";
name = "";
slogan = "";
description = "";
url = "";
telephone: number;
pageUrl: string;
website: string;
founded: number;
organization: number;
email: string;
coverImage: string;
profileImage: string;
specialty?: Specialty[];
branches: Branches[];
locations?: Location[];
phone?:Phone;
userRole?: string;
roles?: Roles[];
}
export class Roles {
role= "";
userID = "";
}
This is the HTML of page.component .
<div class="main" *ngIf="!showWeb">
<div *ngFor="let page of pages$ | async" class="card width-900">
<app-pages-list class="d-flex width-900" [page]="page" [details]="'details'"></app-pages-list>
</div>
<div>
</div>
</div>
This is the TS file.
public pages$: Observable<Page[]>;
ngOnInit(): void {
this.pageService.getPages();
this.pages$ = this.pageService.pageModel();
}
And this is the code when I create new Page.
export class CreatePageComponent implements OnInit {
public page = new Page();
search;
public branch = [];
constructor(public router: Router,
public branchesService: BranchesService,
public authService: AuthService,
public pageService: PagesService,
public shareData: SenderService) { }
ngOnInit(): void {
}
createPage() {
this.page.url = this.page.name;
this.page.branches = this.branch;
this.page.locations = [];
this.page.specialty = [];
this.page.roles = [];
this.page.phone = this.page.phone;
this.page.pageUrl = `${this.page.name.replace(/\s/g, "")}${"-Page"}${Math.floor(Math.random() * 1000000000)}`;
this.pageService.setPage(this.page, this.authService.userID);
}
addBranch(event) {
this.branch.push(event);
this.search = "";
}
removeBranch(index) {
this.branch.splice(index, 1);
}
}

From my understanding of your code, your error is thrown because the data variable hold 2 types of objects.
In the PagesServices:
In getPages you give data a list of Page.
In setPage and updatePage you give data an instance of Page.
private data = new ReplaySubject<any>();
When you create a new page, data hold the last page you created (not an array). Then you try to iterate this page.
<div *ngFor="let page of pages$ | async"
This error come from the fact that you can't iterate a Page object.
You should stop using any so that this type of error occurs at compilation time, not at runtime. Also you need to store an instance of the array of page, add the item in your array after a post, and then replay the whole array.
Code
public updateDate(id: string, page: Page) {
const api = `${this.baseUrl}/page/${id}`;
return this.http.put<any>(api, page).subscribe((res) => {
const index: number = lastSetOfData.findIndex((_page: Page) => _page._id === res._id);
lastSetOfData[index] = res;
lastSetOfData = [...lastSetOfData];
this.data.next(lastSetOfData);
});
}
Also the updateDate function should be named updatePage.

The issue is the one identified in the response from #Marco. I elaborate starting from there.
There are several ways of fixing this problem. Probably the fastest is to add an instance variable lastSetOfData to PagesService where you hold the last version of the array. Then you initiatlize lastSetOfData in the getPages method. Finally in the setPage method you update lastSetOfData appending the Page returned by the service at the end of lastSetOfData and notify it using the ReplaySubject.
So the code could look like this
export class PagesService {
public baseUrl = environment.backend;
// specify the type of data notified by the ReplaySubject
private data = new ReplaySubject<Array<Page>>();
// define lastSetOfData as an array of Pages
private lastSetOfData: Array<Page> = [];
....
public getPages() {
return this.http.get<any>(`${this.baseUrl}/page/${this.userID}`).subscribe(res => {
// res should be an array of Pages which we use to initialize lastSetOfData
lastSetOfData = res;
this.data.next(lastSetOfData)
});
}
....
public setPage(page: Page, id: string) {
const api = `${this.baseUrl}/page`;
const user_id = id;
this.http.post<any>(api, page, {
headers: { user_id }
}).subscribe(res => {
// update lastSetOfData appending resp, which should be a Page
// not the use of the spread operator ... to create a new Array
lastSetOfData = [...lastSetOfData, resp];
// now you notify lastSetOfData
this.data.next(lastSetOfData)
});
}
// probably you have to modify in a similar way also the method updateTable
public updateDate(id: string, page: Page) {
....
}
....
....
}
Consider that this may be the fastest way to fix the problem. Check if it works and then you may want to try to refactor the code to look for a more rx-idiomatic solution. But my suggestion is first to see if this fixes the problem.

Problem is that you put an object in your replaysubject although an array is expected in other places.
next(myarray)
next(myobject)
This does not magically append an object to the array.
To do so, you'd need something like this:
data.pipe(take(1)).subscribe(list => {
list.push(newvalue);
data.next(list);
});
Basically you take the last value, a the new item, and push the new list.

Using ReplaySubject in Angular at PUT Request it is losing the data

I am having an issue with the ReplaySubject, I don't know what I have done wrong but the problem it is that when I change something and save it in backend, the ReplaySubject it calls new data but it is hiding them to show me see the picture.
I tried to use detectChanges but without any luck, but as i know the detectChanges will work only when we have parent -> child iterration.
This happens on update
This happens when I reload the page
If I remove the the this.data.next(res) at this line of the Put Request then it works but I need again to reload page to get new data.
return this.http.put(api, dataModel).subscribe(res => this.data.next(res));
This is the code of the service.
#Injectable({
providedIn: "root"
})
export class ModelDataService {
public baseUrl = environment.backend;
private data = new ReplaySubject<any>();
public userID = this.authService.userID;
constructor(private http: HttpClient, private authService: AuthService) {
}
public getJSON() {
return this.http.get(`${this.baseUrl}/data/${this.userID}`).subscribe(res => this.data.next(res));
}
public dataModel(): Observable<any> {
return this.data.asObservable();
}
public setData(data: Model) {
const api = `${this.baseUrl}/data`;
const user_id = this.authService.userID;
this.http.post(api, data, {
headers: {user_id}
}).subscribe(res => this.data.next(res));
}
public updateDate(id: string, dataModel: Model) {
const api = `${this.baseUrl}/data/${id}`;
return this.http.put(api, dataModel).subscribe(res => this.data.next(res));
}
}
This is the component.
public model$: Observable<Model>;
public model: Model;
constructor(
public authService: AuthService,
private modelDataService: ModelDataService,
public dialog: MatDialog,
public cd: ChangeDetectorRef) {
}
ngOnInit() {
this.authService.getUserProfile(this.userID).subscribe((res) => {
this.currentUser = res.msg;
});
this.modelDataService.getJSON();
this.model$ = this.modelDataService.dataModel();
this.model$.subscribe((data) => {
this.model = data; // here if i try to console log then I have the array but the page it will be blank
console.log(data);
});
}
And then for example I try to show data like this.
<ng-container class="Unit-unit-unitGroup" *ngFor="let personalData of model.personalData; let id = index">
</ng-container>
In the put Request I have added an console log and this is what I am getting.
But on reload I am getting I think another way of strucuter of data.
See picture

Use ChangeDetectorRef to detect changes again in the view when the data comes back.
this.model$.subscribe((data) => {
this.model = data;
this.cd.detectChanges();
});

<ng-container class="Unit-unit-unitGroup" *ngFor="let personalData of model.personalData; let id = index">
</ng-container>
this.model$.subscribe((data) => {
this.model = data; // here if i try to console log then I have the array but the page it will be blank
console.log(data);
});
public updateDate(id: string, dataModel: Model) {
const api = `${this.baseUrl}/data/${id}`;
return this.http.put(api, dataModel).subscribe(res => this.data.next(res));
}
You expect personalData to be a property of your model. However, as seen in the console log your res is an object including data as an object between. All you need to do is mapping res to it's data.
public updateDate(id: string, dataModel: Model) {
const api = `${this.baseUrl}/data/${id}`;
return this.http.put(api, dataModel).subscribe(res => this.data.next(res.data));
}

angular 9 execute subscribe in code behind synchronously

I need to run a method with 2 parameters, each parameter is gotten through some form of subscribe function. the first is the collection which is gotten through the url from angular's page routing. The second is the dokument, this is the firebase's firestore document.
export class FirebaseDocument implements OnInit {
collection: string;
dokument: any;
//== CONSTRUCTORS
constructor(
private route: ActivatedRoute,
private _db: AngularFirestore
) {}
//== Initialize
ngOnInit() {
console.log("__loading page component");
this.route.params.subscribe(params => {
this.collection = params["collection"];
});
console.log(this.collection);//collection populated correctly
//load the document from AngularFirestore
console.log("loading the document from firebase");
let itemsCollection = this._db.collection(url).valueChanges();
//subscribe to get the dok of the first document in the collection
itemsCollection.subscribe(docArr => {
this.dokument = docArr[0];
console.log(this.dokument);//dokument is populated
});
console.log(this.dokument);//dokument is undefined
this.doMultiParameterMethod(this.collection, this.dokument);
}
}
this.collection populates perfectly fine;
this.dokument is only populated inside the subscribe method
I need this to be populated by the time the next line is run. the console.log(this.dokument);
I have been dumbstruck by this because essentially the same code is used by the 2 subscribe methods but they don't behave the same way.

Sometimes a subscribe can be synchronous. This happens when the Observable is a ReplaySubject a BehaviorSubject or an Observable which has a shareReplay() pipe. (probably other options as well.
This will make the observable immediately fire on subscription. However, you should never count on this behavior, and always continue within your subscribe.. Or use pipes like mergeMap and create other observables which you can access in your template using the async pipe.
In your case. The this.route.params is obviously a 'replaying' Observable from which you get the latest value after subscribing. Otherwise you would have to wait for the params to change again until you get a value.
Your Database call cannot return an immediate response, because it's essentially a network request.
In your example code, you can update it to this, and use the async pipe in your template
export class FirebaseDocument implements OnInit {
readonly collection$: Observable<string> = this.route.params.pipe(
map((params) => params.collection)
);
readonly doc$: Observable<any[]> = this.db.collection(this.url).valueChanges().pipe(
shareReplay({ refCount: true, bufferSize: 1 })
);
constructor(private route: ActivatedRoute, private db: AngularFirestore) {}
ngOnInit() {
// don't forget to unsubscribe
combineLatest([
this.collection$,
this.doc$
]).subscribe((collection, document) => {
this.doMultiParameterMethod(collection, document);
});
}
}

Maybe you should make the Observable a Promise, in your case would be the following :
export class FirebaseDocument implements OnInit {
collection: string;
dokument: any;
//== CONSTRUCTORS
constructor(
private route: ActivatedRoute,
private _db: AngularFirestore
) {}
//== Initialize
ngOnInit() {
console.log("__loading page component");
this.route.params.subscribe(params => {
this.collection = params["collection"];
});
console.log(this.collection); //collection populated correctly
this.getDokument().then(docArr => {
this.dokument = docArr[0];
this.doMultiParameterMethod(this.collection, this.dokument);
});
}
getDokument(): Promise<any> {
let itemsCollection = this._db.collection(url).valueChanges();
return new Promise((resolve, reject) => {
itemsCollection.subscribe((response: any) => {
resolve(response);
}, reject);
});
}
}

angular load local file then make http calls to return observables

I am new to Angular, JS, and observables. I have a typescript class called DataService. I want it to load a list of URLs from a JSON formatted local file, and then have some way to call those URLs (to a handful of REST APIs) and return observables. The problem I am having is my code is not waiting for the config file to be loaded before the REST API functions get called.
I thought I could have the DataService constructor load the configuration file, and then have unique functions for each REST API call, but that isn't working
my code:
export class DataService {
configFile
constructor(private http: HttpClient) {
this.http.get('/assets/restApiUrlListConfig.json').subscribe(config => {
this.configFile = config;
});
}
getUrlFromConfigFile(name: string): string {
...
this returns the URL from the config file
...
}
getUrlAData(): Observable {
return this.http.get( getUrlFromConfigFile('A') )
}
}
My other components have code like this:
export class SomeComponent implements OnInit {
someComponentAData
constructor(private data: DataService) { }
ngOnInit() {
this.data.getUrlAData().subscribe(
data => {
this.someComponentAData = data
}
)
}
I am getting an error that the observable returned from the dataservice is undefined. Which I believe is because the constructor hasn't finished loading the config file, which I think is why the function getUrlAData isn't returning anything.
I feel like I'm not correctly handling these async calls, but I'm at a loss for how to tell my code to :
create the data service object
load the data file before anything else can be done
allow the other functions to be called asyncronously AFTER the config file is loaded
Angular CLI: 6.2.3
Node: 8.12.0
OS: win32 x64
Angular: 6.1.8
Edit 1: attempting to implement suggested solution
My DataService
configFile
configObservable: Observable<any>;
someSubscribeObj
constructor(private http: HttpClient) {
this.someSubscribeObj = this.http.get('/assets/restApiUrlListConfig.json').subscribe(config => {
this.someSubscribeObj = undefined;
this.configFile = config;
});
}
getObsFromConfigFile(name: string): Observable<any> {
//...
if (this.configFile != undefined) {
console.log('this.restApiUrlListConfig[name]',this.configFile[name])
return of(this.configFile[name])
}
else
return of(this.someSubscribeObj.pipe(map(c => c[name])))
//this.configObservable
//...
}
getUrlAData(): Observable<any> {
return this.getObsFromConfigFile('A').pipe(mergeMap(url => this.http.get(url)))
}
My other component:
constructor( private data: DataService ) { }
ngOnInit() {
//this.data.loggedIn.pipe((p) => p);
this.data.getUrlAData().subscribe(
data => {
this.urlAData = data
}
)
}
I was unable to store the "subscribe" into the observable, so I created a generic Any type varable, but at runtime I get a problem with the pipe command:
TypeError: this.someSubscribeObj.pipe is not a function
at DataService.push../src/app/services/data.service.ts.DataService.getObsFromConfigFile
(data.service.ts:67)
at DataService.push../src/app/services/data.service.ts.DataService.getUrlAData
(data.service.ts:74)
Edit 2: the unfortunate workaround
I am currently using two nested subscriptions to get the job done basically
http.get(config_file_url).subscribe(
config => {
http.get( config['A'] ).subscribe( adata => { do things };
http.get config['B'].subscribe( bdata => {do things };
}
)
I feel like I should be able to use a mergeMap of some sort, but I couldn't get them to work as I thought they would.

You need to wait on that async call, I would use a flatmap to get the value out of an observable.
export class DataService {
configFile
configObservable: Observable<any>;
constructor(private http: HttpClient) {
this.configObservable = this.http.get('/assets/restApiUrlListConfig.json').pipe(
map(config => {
this.configObservable = undefined;
this.configFile = config;
return configFile;
})
);
}
getUrlFromConfigFile(name: string): Observable<string> {
...
return of(configFile[name]) if configFile is set else return configObservable.pipe(map(c => c[name]));
...
}
getUrlAData(): Observable<string> {
return this.getUrlFromConfigFile('A').pipe(map(url => this.http.get(url)))
}
}
Basically you want to store the observable and keep using it till it completes, after it completes you can just wrap the config in an observable. The reason for wrapping it is to make the interface consistent, otherwise you have to have an if before every get.

set and get data from service angular 5

I am using angular 5
my scenario is from one component im setting the data in service and from another component i'm getting that data|
Component- 1:
makeUser(row){
this.agentsService.setSelectedAgentData(row); // setting the data (row) in agentsService.
const mrf = this.modalService.open(MakeUserComponent);
}
Service:
declaring the varible in class.
public selectedData:any = {};
setter and getter methods are as below
setSelectedAgentData(selectedTableRowData){
this.selectedData = selectedTableRowData;
}
getSelectedAgentData(){
return this.selectedData;
}
Component - 2:
ngOnInit() {
this.userDetails = this.agentsService.getSelectedAgentData();
this.roles = this.agentsService.getRolesList();
}
Here the selectedData value is an empty object when I call the method this.agentsService.getSelectedAgentData() from component -2
Any help would be appreciated.

You can use Subject (rxjs library) for this purpose. So Subject can generate data on the one hand. And on the other hand, you can subscribe to changes in any place.
You service would look like this:
#Injectable()
export class YourService {
public selectedData: Subject<any>;
constructor() {
this.selectedData = new Subject();
}
generateSelectedAgentData(row: string) {
this.selectedData.next(row);
}
}
In your first Component:
makeUser(row){
this.agentsService.generateSelectedAgentData(row);
const mrf = this.modalService.open(MakeUserComponent);
}
In your second Component:
constructor(private ys: YourService){
this.ys.selectedData.subscribe(
data => {
console.log(data);
this.userDetails = data;
});
}