angular - 将 ngModel 绑定(bind)到动态复选框列表 : Angular 2/Typescript

Question

我不确定绑定(bind)和更新动态生成复选框的模型的正确方法。 (这是一个 ASP.NET Core 项目，Angular 2 最初是使用 Yeoman 生成器创建的)或者我刚刚发现的一个简单的复选框。

下面是精简的代码，它有一个设施和时间段。每个设施可以有多个时隙。时隙复选框列表显示正常。初始数据表明只应检查一个时隙。但是当我加载一个设施时，所有的时间段都会被检查。它们没有像我预期的那样与 ngModel 绑定(bind)。

1. 如何修复它以便只检查设施数据中包含的时间段而不是所有时间段？
2. 如何将选中的内容绑定(bind)到 ngModel timeslotids 属性？我是否需要在组件上创建一个数组属性并对其进行操作而不是依赖 ngModel？ (试过这个但显然没有做对所以恢复到下面的代码)
3. 我似乎也遇到了绑定(bind)到一个简单的复选框(有电)的问题，因为它也没有在应该的时候勾选。我是否缺少可以解决所有这些问题的导入？

代码解释我有两个对象(设施和时隙)来 self 绑定(bind)到接口(interface)的 api。为了简单起见，它们的属性已大大减少:

export interface IFacility {   
   id: number,
   name: string,
   haselectric: boolean, 
   timeslotids: number[],    
   timeslots: ITimeslot[]

}
export interface ITimeslot {
    id: number,
    timeslotname: string    
}

这是时间段的 JSON 数据:

[{"id":1,"timeslotname":"Daily"},{"id":2,"timeslotname":"Hourly"},{"id":4,"timeslotname":"Market"}]

这是更新前单个设施的 JSON 数据:

{"id":2,"name":"Clements Building","haselectric":true,"timeslotids":[1],"timeslots":[{"id":1,"timeslotname":"Daily"}]}

用于编辑设施的组件 (facility.component.html):

<form #form="ngForm" (ngSubmit)="submitForm()" *ngIf="formactive">
   <input type="hidden" [(ngModel)]="updatedfacility.id" #id="ngModel" name="id" />
    <div class="form-group">
         <label for="name">Facility Name *</label>
         <input type="text" class="form-control input-lg" [(ngModel)]="updatedfacility.name" #name="ngModel" name="name" placeholder="Facility Name *">
   </div>
   <div class="form-group">
                    <label for="exhibitspaces">Has Electric *</label>
                    <input type="checkbox" class="form-control input-lg" [(ngModel)]="updatedfacility.haselecric" #haselectric="ngModel" name="haselectric">
    </div>
    <div class="form-group">
        <label for="timeslots">Select Timeslots Available for Rent *</label>
        <div *ngIf="dbtimeslots" >
            <span *ngFor="let timeslot of dbtimeslots" class="checkbox">
                <label for="timeslot">
                    <input type="checkbox" [(ngModel)]="updatedfacility.timeslotids" value="{{timeslot.id}}" name="{{timeslot.id}}" [checked]="updatedfacility.timeslotids.indexOf(timeslot.id)" />{{timeslot.timeslotname}}
                 </label>
             </span>
        </div>
    </div>
    <button type="submit" class="btn btn-lg btn-default" [disabled]="form.invalid">Update</button> 
</form>

组件代码 (facility.component.ts)

import { Component, OnInit, Input, Output, OnChanges, EventEmitter  } from '@angular/core';
import { Observable } from 'rxjs/Observable';
import { ActivatedRoute, Router } from '@angular/router'; 
import { FormsModule }  from '@angular/forms';
import { FacilityService }  from '../../../services/facility.service';
import { TimeslotService } from '../../../services/timeslot.service';
import { IFacility } from '../../../services/facility.interface';
import { ITimeslot } from '../../../services/timeslot.interface';

@Component({
   template: require('./facility.component.html')
})
export class FacilityDetailsComponent {
  facility: IFacility;
  httpresponse: string;
  successMessage: string;
  errormessage: string;
  showSuccess: boolean = true;
  showError: boolean = true;
  formactive: boolean = true;
  dbtimeslots: ITimeslot[];    


  constructor(
    private _route: ActivatedRoute,
    private _router: Router,
    private _facilityservice: FacilityService,
    private _timeslotservice: TimeslotService
  ) {}

  ngOnInit(): void {
    this._timeslotservice.getTimeslots().subscribe(timeslots => this.dbtimeslots = timeslots, error => this.errormessage = <any>error);
    let id = +this._route.snapshot.params['id'];

    this._facilityservice.getFacility(id)
        .subscribe(facility => this.facility = facility,
        error => this.errormessage = <any>error);

  }

  submitForm() {
    //update the facility through the service call
    this._facilityservice.updateFacility(this.facility)
        .subscribe(response => {
            this.httpresponse = response;
            console.log(this.httpresponse);
            this.successMessage = "Facility updated!";
            this.formactive = false;
            setTimeout(() => this.formactive = true, 3);
            this.showSuccess = false;
        },
        error => {
            this.errormessage = <any>error;
            this.showError = false;
        });
  }     

附言我在时隙的设施对象中有两个属性的原因是因为 id 列表更容易传递给 API 进行更新。而不是传递完整的模型(时隙比我这里的要大，不需要更新数据库)。请保留对此的评论，因为它与需要完成的工作无关。

我发现了这个问题……但遗憾的是，没有人回答这个可怜的家伙:ngmodel binding with dynamic array of checkbox in angular2试过这个但没有用:Get values from a dynamic checkbox list我还尝试了在复选框的(更改)上更新本地属性的版本，但这似乎也不起作用:Angular 2: Get Values of Multiple Checked Checkboxes

Answer 1

根据上面 НЛО 的回答，我找到了我的问题的解决方案。谢谢НЛО。

<div class="form-group">
    <label for="timeslots">Select Timeslots Available for Rent *</label>
    <div *ngIf="dbtimeslots">
        <span *ngFor="let timeslot of dbtimeslots" class="checkbox">
            <label>
                <input type="checkbox" value="{{timeslot.id}}" name="{{timeslot.id}}"  [checked]="(facility.timeslotids && (-1 !== facility.timeslotids.indexOf(timeslot.id)) ? 'checked' : '')" (change) ="updateSelectedTimeslots($event)" />{{timeslot.timeslotname}}
            </label>
         </span>
    </div>
</div>

然后是组件上的函数:

updateSelectedTimeslots(event) {
    if (event.target.checked) {
          if (this.facility.timeslotids.indexOf(parseInt(event.target.name)) < 0) { 
                this.facility.timeslotids.push(parseInt(event.target.name));

          }
     } else {
           if (this.facility.timeslotids.indexOf(parseInt(event.target.name)) > -1) 
            {
                this.facility.timeslotids.splice(this.facility.timeslotids.indexOf(parseInt(event.target.name)), 1);              
            }
    }
     //console.log("TimeslotIDs: ", this.facility.timeslotids);    
}