因此,我有一个表,该表使用从服务中获取的数据进行填充,该服务器内的方法已连接到nodeJS API。
由于数据是从后端获取的,所以我尝试在服务上使用BehaviourSubject并将其初始化为未定义:
服务:
mport { Injectable } from "@angular/core";
import { HttpClient } from "@angular/common/http";
import { Voluntario } from "./voluntario.model";
import { BehaviorSubject } from "rxjs";
@Injectable({
providedIn: "root"
})
export class VoluntarioService {
private endpoint = "http://localhost:3000";
public voluntariosChanged = new BehaviorSubject(undefined); //prueba refresh
constructor(private httpClient: HttpClient) {}
getVoluntarios() {
return this.httpClient.get<Voluntario[]>(this.endpoint + "/voluntarios");
}
getVoluntario(id: string) {
return this.httpClient.get<Voluntario>(
this.endpoint + "/voluntarios/" + id
);
}
createVoluntario(voluntario: Voluntario) {
return this.httpClient.post<Voluntario>(
this.endpoint + "/voluntarios",
voluntario
);
}
updateVoluntario(voluntario: Voluntario, id: string) {
return this.httpClient.put<Voluntario>(
this.endpoint + "/voluntarios/" + id,
voluntario
);
}
deleteVoluntario(id: string) {
return this.httpClient.delete<Voluntario>(
this.endpoint + "/voluntarios/" + id
);
}
}
我想做的是每当我创建,编辑或删除新的“ Voluntario”时刷新列表组件。创建和编辑在不同的组件中完成,而删除也在不同的组件中。 我首先尝试使用edit组件,所以做到了:
import { Component, OnInit, ViewChild } from "@angular/core";
import { VoluntarioService } from "../voluntario.service";
import { Voluntario } from "../voluntario.model";
import { ActivatedRoute, Params } from "@angular/router";
@Component({
selector: "app-voluntarios-edit",
templateUrl: "./voluntarios-edit.component.html",
styleUrls: ["./voluntarios-edit.component.css"]
})
export class VoluntariosEditComponent implements OnInit {
voluntarios: Voluntario[]; //pal refresh
voluntario: Voluntario = {
_id: null,
volName: null,
cedula: null,
age: null,
tel: null,
sex: null,
email: null
};
id: string;
editMode = false;
constructor(
private voluntarioServicio: VoluntarioService,
private route: ActivatedRoute
) {}
ngOnInit() {
this.route.params.subscribe((params: Params) => {
this.id = params["id"];
this.editMode = params["id"] != null;
console.log(this.editMode);
});
//prepopulacion
if (this.editMode) {
this.voluntarioServicio.getVoluntario(this.id).subscribe(
result => {
console.log(result);
this.voluntario = {
_id: result._id,
volName: result.volName,
cedula: result.cedula,
age: result.age,
tel: result.tel,
sex: result.sex,
email: result.email
};
},
error => console.log(error)
);
}
}
onSubmit() {
if (this.editMode) {
this.voluntarioServicio
.updateVoluntario(this.voluntario, this.id)
.subscribe(
result => {
console.log("Voluntario actualizado con exito", result);
this.voluntarioServicio.voluntariosChanged.next(result);
},
error => console.log(error)
);
} else {
this.voluntarioServicio.createVoluntario(this.voluntario).subscribe(
result => {
console.log("Voluntario creado con exito", result);
this.voluntarioServicio.voluntariosChanged.next(result);
},
error => console.log(error)
);
}
//refresh
}
}
最后在清单组件中,我尝试在ngOnInit上调用voluntariosChanged BehaviourSubject:
ngOnInit() {
this.voluntarioService.getVoluntarios().subscribe(
result => {
this.voluntarios = result;
console.log("Voluntario fetcheado con exito");
},
err => console.log(err)
);
this.voluntarioService.voluntariosChanged.subscribe(
result => {
this.voluntarios = result ;
},
err => console.log(err)
);
}
但是它不起作用...我对Angular真的很陌生,我一直在搜索这个问题,但我想我做错了什么。另外,我必须指出,列表组件和编辑组件不是父子组件,它们是不相关的。
答案 0 :(得分:0)
一种实现此目的的方法是使用Subject而不是BehaviorSubject
public voluntariosChangedSource: Subject<Voluntario> = new Subject<Voluntario>();
public voluntariosChanged$: Observable<Voluntario> = this.voluntariosChangedSource.asObservable();
在您的编辑组件中使用它,以便:
this.voluntarioServicio.voluntariosChangedSource.next(result);
在列表组件中,您只需调用:
this.voluntarioService.voluntariosChanged$.subscribe(
result => {
this.voluntarios = result ;
},
err => console.log(err)
);
请参见此答案https://stackoverflow.com/a/43351340/3733665,Subject和BehaviorSubject之间的区别