Ionic 3-从组件发送数据到服务 [英] Ionic 3 - Sending data to service from component

问题描述

我正在尝试从我的组件中发送一个对象，该对象是从用户的输入到我所拥有的服务的.

I am trying to send an object from my component which is from the input of the user to the service I have.

这是我的代码.

Sample.html

Sample.html

<ion-item>
    <ion-label color="primary">Subject</ion-label>
    <ion-select [(ngModel)]="attendanceSet.subject">
        <ion-option *ngFor="let subject of subjects" [value]="subject.title">{{subject.title}}</ion-option>
    </ion-select>
</ion-item>
<ion-item>
    <ion-label color="primary">Date</ion-label>
    <ion-datetime [(ngModel)]="attendanceSet.date" displayFormat="DDD MMM DD" pickerFormat="YYYY MM DD"></ion-datetime>
</ion-item>

<button ion-button block padding (click)="proceed(attendanceSet)">Proceed</button>

Sample.ts

Sample.ts

public attendanceSet = {}

proceed(attendanceSet) {
    this.navCtrl.push(CheckAttendancePage, {
        setData: attendanceSet
    });
}

服务

private attendanceListRef: AngularFireList<Attendance>

public setAttendance = {}

constructor(private db: AngularFireDatabase, private events: Events, public navParams: NavParams, private method: CheckAttendancePage){

    this.attendanceListRef = this.db.list<Attendance>('attendance/')

}

addAttendance(attendance: Attendance) {
    return this.attendanceListRef.push(attendance)
}

我想做的是从sample.html获取数据，稍后将使用它来定义"attendanceListRef"路径.像这样的出勤/主题/日期"

What I'm trying to do is getting data from the sample.html which I will later use to define the path of the "attendanceListRef" like this "attendance/subject/date"

是否有任何适当或替代的方法来做到这一点?谢谢！

Is there any proper or alternative way to do this? Thanks!

推荐答案

使用Angular将数据发送到 Service 非常简单.在此示例中，我将给您三个选择.

It's quite simple to send data to a Service with Angular. I'll give you three options in this example.

service.ts

import { Injectable } from '@angular/core';
import { Events } from 'ionic-angular';
    
@Injectable()
export class MyService {
    // option 1: Using the variable directly
    public attendanceSet: any;
    
    // option 3: Using Ionic's Events
    constructor(events: Events) {
        this.events.subscribe('set:changed', set => {
            this.attendanceSet = set;
        });
    }
       
    // option 2: Using a setter
    setAttendanceSet(set: any) {
        this.attendanceSet = set;
    }
}

在您的 Component 中，您可以执行以下操作.

In your Component you can do the following.

import { Component } from '@angular/core';
import { Events } from 'ionic-angular';
// import your service
import { MyService } from '../../services/my-service.ts';

@Component({
    selector: 'something',
    templateUrl: 'something.html',
    providers: [MyService] // ADD HERE -> Also add in App.module.ts
})

export class Component {
    newAttendanceSet = {some Object};
    
    // Inject the service in your component
    constructor(private myService: MyService) { }
    
    proceed() {
        // option 1
        this.myService.attendanceSet = this.newAttendanceSet;
         
        // option 2
        this.myService.setAttendanceSet(this.newAttendanceSet);
     
        // option 3
        this.events.publish('set:changed', this.newAttendanceSet);
    }
}

基本上，我建议您选择选项1或2.在我看来，3被认为是不好的做法，但是它仍然可以工作，并且如果您需要在多个服务/组件上更新价值，有时可以提供极大的灵活性.

Basically I'd recommend option 1 or 2. 3 is considered bad practice in my eyes but it still works and sometimes allows for great flexibility if you need to update your value over multiple services/components.

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