how to display @feathersjs-client results in Angular

问题

In process to integrate feathersjs-client into an angular frontend using feathers-chat-angular code as a guide. Backend up and running: MongoDB, Mongoose, express/feathers server. Was able to retrieve data from the frontend, got stuck displaying the response data. Feathers-reactive currently not used. Warning beginner@work ...

Was looking into Observables but always ran into: ERROR: Uncaught (in promise): TypeError: this.dataService.issues$(...).pipe... is not a function.

Played around with .map() and .subscribe() basically, same is not a function error. Thxs in advance.

Code myNg component

import { Component, OnInit, ChangeDetectionStrategy } from '@angular/core';
import { Observable, pipe } from 'rxjs';
import { map } from 'rxjs/operators';
import { Issue } from '../../issue.model';
import { Router } from '@angular/router';
import { DataService } from '../../services/data.service';
//import { Paginated } from '@feathersjs/feathers';

@Component({
  selector: 'app-list',   
  templateUrl: './list.component.html',
  styleUrls: ['./list.component.css'],
  changeDetection: ChangeDetectionStrategy.OnPush
})
export class ListComponent implements OnInit {
  issues$: Observable<Issue[]>;

  constructor(private dataService: DataService) {
//something goes wrong here !!!
    this.issues$ = this.dataService.issues$();
  }

  ngOnInit() {
  } 
}

Code DataService:

import { Injectable } from '@angular/core';
import { FeathersService } from './feathers.service';

@Injectable({
  providedIn: 'root'
})
export class DataService {
  constructor(private feathers: FeathersService) {}

  issues$() {
    let results = this.feathers.service('issues').find();
    console.log(results); //Works records retrieved
    return this.feathers
      .service('issues')
      .find();
  } 
}

Feathers Service:

import { Injectable } from '@angular/core';
import feathers from '@feathersjs/feathers';
import socketio from '@feathersjs/socketio-client';
import io from 'socket.io-client';

@Injectable({
  providedIn: 'root'
})
export class FeathersService {
  private client = feathers();                         
  private socket = io('http://localhost:3030'); 

  constructor() {
    this.client
      .configure(socketio(this.socket))
  };


  //expose services
  public service(name: string) {
    return this.client.service(name);
  }
}

回答1:

It looks like find function is returning a Promise according to feathersjs documentation:

Service methods must use async/await or return a Promise and have the following parameters

In this case, you'll need to return your promise as an observable using from operator like this:

import { from } from 'rxjs';
const observable = from(promise);

Implemented in your code:

Code DataService:

import { Injectable } from '@angular/core';
import { from } from 'rxjs';
import { FeathersService } from './feathers.service';

@Injectable({
  providedIn: 'root'
})
export class DataService {
  constructor(private feathers: FeathersService) {}

  issues$() {
    let results = this.feathers.service('issues').find();
    console.log(results); //Works records retrieved
    return from(this.feathers
      .service('issues')
      .find());
  } 
}

来源：https://stackoverflow.com/questions/57792756/how-to-display-feathersjs-client-results-in-angular

标签

angular

rxjs

observable

feathersjs