旧值保留在 ngModel 更改上

Question

Dealing with a table which need a filter by data, I've created the following screen:

What I need is to remove values outside the date start criteria of the filter so I've done this on my EsightComponent :

startDateChange($event, dt, col) {
  this.loading = true;
  this.eSightEndSubscription = this.eSightService.getByContractId(this.contractId).subscribe(
    res => {
      const filterResults = this.reads.filter((read) => {
        const iteratorDate = new Date(20 + read.timestamp.slice(-2), read.timestamp.slice(0, 2) - 1, 1);
        console.log(this.startDateFilter);
        return iteratorDate <= this.startDateFilter;
      }, this);

      this.processRightAnswer(filterResults);
    },
    error => {
      console.log('ERROR');
    },
    () => {
      this.loading = false;
    });
}

And this is my view:

<h4>Lecturas eSight <small>contrato {{ contractId }}</small></h4>

<p-calendar dateFormat="mm/yy" [(ngModel)]="startDateFilter" (onBlur)="startDateChange($event, dt, col)"></p-calendar>
<p-calendar [(ngModel)]="endDateFilter" (change)="startDateChange($event, dt, col)"></p-calendar>

<p-dataTable [value]="reads" [rows]="30" [paginator]="true" [loading]="loading" selectionMode="single" scrollable="true" #dt>
  <ng-container *ngFor="let col of cols; let i = index;">
    <p-column [field]="col.field" [header]="col.header" *ngIf="i === 0" [style]="{ 'width': '170px' }">
    </p-column>
    <p-column [field]="col.field" [header]="col.header" *ngIf="col.header.length <= 10" [style]="{ 'width': '55px' }"></p-column>
    <p-column [field]="col.field" [header]="col.header" *ngIf="col.header.length > 10" [style]="{ 'width': '170px' }"></p-column>
  </ng-container>
</p-dataTable>

<button class="btn btn-warning" (click)="onReturn()">Atrás</button>

Based on tho way data binding principle, this.startDateFilter should catch changes on it, but it doesn't. If I select a date on the calendar, it always displays the previous value, not the selected new one. That is seen on console.log(this.startDateFilter) line.

I've checked I could use ngOnChanges to catch changes and to have access to both old and new values, but this hook just works for @Input() values and this is not my case.

I wish to retrieve the value selected by the user and not an old one.

Thanks.

Answer 1

It's happens because ngModel triggers after change datection, but you are watching for blur, that fires before detection

You should getting current value from $event, not from model value. Something line

$event.value

Answer 2

基于 DmitriyKhirniy 的回答（非常感谢！！！），最终有效的是：

$event.target.value