Angular项目Project Service

建立领域对象并在domain中建立一个index.ts用于组织文件。在index.ts中导出所有的领域对象。

 1，新建project.service，加add方法。

import { Project } from './../domain';
import { HttpClient } from '@angular/common/http';
import { Inject, Injectable } from '@angular/core';
import { map } from 'rxjs/operators';

@Injectable({
  providedIn: 'root'
})
export class ProjectService {
  private readonly domain = 'projects';
  private headers = new Headers({
    'Content-type': 'application/json'
  });
  constructor(private httpClient: HttpClient, @Inject('BASE_CONFIG') private config: any) { }

  //POST
  add(project: Project) {
    project.id = undefined;
    const uri = `${this.config.uri}/${this.domain}`;
    return this.httpClient.post(uri, JSON.stringify(project)).pipe(
      map(res => res as Project)
    )
  }
}

2，加更新方法

 PUT会全部更新，patch只更新部分属性。不要图方便去做方法范围之外的更新。用一个toUpdate指定只更新这3个属性。

 //PUT/patch
  update(project: Project): Observable<Project> {
    const uri = `${this.config.uri}/${this.domain}/${project.id}`;
    const toUpdate = {
      name: project.name,
      desc: project.desc,
      coverImg: project.coverImg
    }
    return this.httpClient.patch(uri, JSON.stringify(toUpdate)).pipe(
      map(res => res as Project)
    )
  }

3,删除

 project是一个顶级元素，级联删除。删除一个project需要删除Project，project关联的所有列表task-list和列表下面的所有任务task。

 json-server会级联删除，所以我们删除列表和它下面的tasks。

从taskLists数组中得到Observable流。

  //DELETE
  delete(project: Project): Observable<Project> {
    const delTasks$ = from(project.taskLists ? project.taskLists : []).pipe(
      mergeMap(listId => this.httpClient.delete(`${this.config.uri}/taskLists/${listId}`)),
      count()
    );
    const uri = `${this.config.uri}/${this.domain}/${project.id}`;
    return delTasks$.pipe(
      switchMap(_ => this.httpClient.delete(uri).pipe(
        mapTo(project)
      ))
    )
  }

 4，get

//GET
  get(userId: string): Observable<Project[]> {
    const uri = `${this.config.uri}/${this.domain}`;
    return this.httpClient.get(uri, { params: { 'members_like': userId } }).pipe(
      map(res => res as Project[])
    )
  }