rxjs5

问题 I make this code for test forkJoin but it does not work! Can you check what is the problem? const observables = []; observables.push(new Observable(subscriber => subscriber.next('Hello'))); observables.push(new Observable(subscriber => subscriber.next(' '))); observables.push(new Observable(subscriber => subscriber.next('World') )); observables.push(new Observable(subscriber => subscriber.next('!'))); forkJoin(observables).subscribe(word => console.log(word.join(''))); 回答1: Try this const

问题 I am confused about using httpclient in angular 5.I am new to angular and just following the official angular tutorial.I dont know much about observables,promise,pipe etc..Currently I am having a service for handling all the http methods.For post request I am using with pipe.Below is the method. create(model: any,URI) :Observable<Object>{ return this.http.post(API_URL+URI, model) .pipe( catchError(this.handleError('create', model)) ); } private handleError<T> (operation = 'operation', result?

问题 For a JWT authentification, I make a post request to get the token using the new Http module working with Observables now. I have a simple Login component showing the form: @Component({ selector: 'my-login', template: `<form (submit)="submitForm($event)"> <input [(ngModel)]="cred.username" type="text" required autofocus> <input [(ngModel)]="cred.password" type="password" required> <button type="submit">Connexion</button> </form>` }) export class LoginComponent { private cred: CredentialsModel

问题 For a JWT authentification, I make a post request to get the token using the new Http module working with Observables now. I have a simple Login component showing the form: @Component({ selector: 'my-login', template: `<form (submit)="submitForm($event)"> <input [(ngModel)]="cred.username" type="text" required autofocus> <input [(ngModel)]="cred.password" type="password" required> <button type="submit">Connexion</button> </form>` }) export class LoginComponent { private cred: CredentialsModel

问题 I have a requirement to listen to a stream of items from an observable. When certain conditions arise an asynchronous task will be performed on the item and the component will be 'busy' until this completes. I would like to pause handling items in the subscription until this task has completed (as the processing of the following items is dependent on the result) and then resume from the next item in the sequence without any loss. the next part is probably best read whilst looking at the Plunk

问题 I want to incrementally increase the delay for this: const source = from(839283, 1123123, 63527, 4412454); // note: this is random const spread = source.pipe(concatMap(value => of(value).pipe(delay(1000)))); // how to incrementally increase the delay where the first item emits in a second, the second item emits in three seconds, the third item emits in five seconds, and the last item emits in seven seconds. spread.subscribe(value => console.log(value)); I'm aware of using interval to

问题 I have this method to get token via localstorage, if token is not exist or is expired, I will call API to get another token and store to localstorage. In this case, which map should I use, currently using mergeMap, or other way to do this? public doGetToken():Observable<Token> { return this.loadToken().pipe( //get via localstorage map(token=>{ let valid = this.validateTokenIsValid(token); let data = { token: token, valid: valid }; return data; }), mergeMap(data=>{ if (!data.valid) { return

问题 Use case: Call a function every minute (60000 ms) that dispatches store action to fetch lastUpdated status of items, which upon response and filtering, updates the store, and updated store is read as an observable and displayed in the view). This needs to happen for as long as the web app is open (so indefinitely). Currently, I'm using this: this.refreshDate = window.setInterval( () => this.store.dispatch(new FetchLastUpdate()) , 60000); And when view is destroyed/dismounted, I delete the

问题 Use case: Call a function every minute (60000 ms) that dispatches store action to fetch lastUpdated status of items, which upon response and filtering, updates the store, and updated store is read as an observable and displayed in the view). This needs to happen for as long as the web app is open (so indefinitely). Currently, I'm using this: this.refreshDate = window.setInterval( () => this.store.dispatch(new FetchLastUpdate()) , 60000); And when view is destroyed/dismounted, I delete the

问题 Use case: Call a function every minute (60000 ms) that dispatches store action to fetch lastUpdated status of items, which upon response and filtering, updates the store, and updated store is read as an observable and displayed in the view). This needs to happen for as long as the web app is open (so indefinitely). Currently, I'm using this: this.refreshDate = window.setInterval( () => this.store.dispatch(new FetchLastUpdate()) , 60000); And when view is destroyed/dismounted, I delete the