如何检测angular2中的bootstrap datetimepicker更改事件

Question

我在角度2中使用bootstrap datetimepicker

https://eonasdan.github.io/bootstrap-datetimepicker/

在我的模板中,我有:

<div class='input-group date datepicker'>
         <input type='text' class="form-control" [(ngModel)]="date">
         <span class="input-group-addon">
         <span class="glyphicon glyphicon-calendar" (click)="getCalendar()"></span>
       </span>
   {{date}}
</div>

问题是当我通过点击选择日历上的日期时,它不会触发任何"更改"事件(换句话说,ngModel不会触发).如果我在文本框中输入,则{{date}}显示值加上我键入的文本.

如果用户单击选择器中的日期进行更改,如何检测文本框中的更改？

Answer 1

问题是Angular不知道输入的值已经改变以便更新ngModel.另一个奇怪的事情是bootstrap-datetimepicker不会在输入上触发change事件 - 这需要一些解决方法.

看这个工作示例:

<div class='input-group date datepicker'>
  <input type='text' class="form-control" #datePicker [ngModel]="date" (blur)="date = datePicker.value">
  <span class="input-group-addon">
    <span class="glyphicon glyphicon-calendar" (click)="getCalendar()"></span>
  </span>

  {{date}}
</div>

注意这些变化:

• [ngModel]="date":我们只需要单向数据绑定(从模型到视图),因为Angular不知道输入的值何时发生了变化
• #datePicker:我已经创建了一个局部变量来访问它的值
• (blur)="date = datePicker.value":在模糊时,我们更新模型

Answer 2

尝试ngModelChange代替change.

<input class="form-control" (ngModelChange)="changeDate($event)"
      [(ngModel)]="startRegistrationDate" ngbDatepicker #start="ngbDatepicker">

// to catch the event
changeDate(event: any) {
  console.log(event);
}

Answer 3

其他答案所述的问题是ngModel没有接受第三方库所做的更改.ngModel使用双向数据绑定.基本上,当你说

<div [(ngModel)]="date">

这相当于

<div [ngModel]="date" (ngModelChange)="date=$event">.

我所做的是创建一个发出ngModelChange事件的指令,如下所示:

@Directive({
    selector: [datepicker],
    outputs: [
        "ngModelChange"
    ]
})
export class DatePickerDirective {
    //Emits changes to ngModel
    ngModelChange = new EventEmitter();
    el: JQuery;

    //Obtains the handle to the jQuery element
    constructor(el){
        this.el = jQuery(el.nativeElement);
    }

    ngOnInit() {
        this.el.datetimepicker({
            //Initialization options
        });

        this.el.on('dp.change', (event) => {
            var moment: Moment = event.date;

            //Emit new value
            this.ngModelChange.emit(date.format(/*However you want it formatted*/));
        });
    };

    ngOnDestroy() {
        //Clean up
        this.el.data('DateTimePicker').destroy();
    };
};

Answer 4

user3169887发布的解决方案对我很有用,直到我从模板驱动的表单(使用ngModel)切换到被动表单.

进一步研究原始问题,我了解到Angular正在监听这些日期选择器库不会触发的"输入"事件.我的解决方案是调整指令以触发"输入"事件而不是发出ngModelChange事件.我用模板驱动的形式和反应形式测试了这个指令,两者似乎都有效.

import { Directive, ElementRef, Renderer, Input, OnInit } from "@angular/core";

declare var $: any;

@Directive({
    selector: "[datepicker]"
})
export class DatePickerDirective implements OnInit {
    @Input("datepicker")
    private datepickerOptions: any = {};
    private $el: any;

    constructor(private el: ElementRef, private renderer: Renderer) {
        this.$el = $(el.nativeElement);
    }

    ngOnInit() {
        // Initialize the date picker
        this.$el.datepicker(this.datepickerOptions)
            // Angular is watching for the "input" event which is not fired when choosing
            // a date within the datepicker, so watch for the "changeDate" event and manually
            // fire the "input" event so that Angular picks up the change
            // See: angular/modules/@angular/forms/src/directives/default_value_accessor.ts
            .on("changeDate", (event) => {
                let inputEvent = new Event("input", { bubbles: true });
                this.renderer.invokeElementMethod(this.el.nativeElement, "dispatchEvent", [inputEvent]);
            });
    };

    ngOnDestroy() {
        this.$el.datepicker("destroy");
    };
};

请注意,我正在使用不同的datepicker库,因此我正在侦听"changeDate"事件,并且您的库可能会触发不同的事件,如"dp.change".