Angular 2 Date Input not binding to date value

问题:

trying to get a form set up but for some reason, the Date input in my html is not binding to the object's date value, despite using [(ngModel)]

html:

<input type='date' #myDate [(ngModel)]='demoUser.date'/><br>

form component:

export class FormComponent {
    demoUser = new User(0, '', '', '', '', new Date(), '', 0, [], []);  
}

User class:

export class User {
    constructor (
        public id: number,
        public email: string,
        public password: string,
        public firstName: string,
        public lastName: string,
        public date: Date,
        public gender: string,
        public weight: number,
        public dietRestrictions: string[],
        public fitnessGoals: string[]
    ){

    }
}

A test output reveals the current "new" Date as the object's value, but the input doesn't update the User object's date value or reflect the value, suggesting neither of the two-way bindings are working. Help would be greatly appreciated.

回答1:

Angular 2 , 4 and 5 :

the simplest way : plunker

<input type="date" [ngModel] ="dt | date:'yyyy-MM-dd'" (ngModelChange)="dt = $event">

回答2:

Instead of [(ngModel)] you can use:

// view
<input type="date" #myDate [value]="demoUser.date | date:'yyyy-MM-dd'" (input)="demoUser.date=parseDate($event.target.value)" />

// controller
parseDate(dateString: string): Date {
    if (dateString) {
        return new Date(dateString);
    } else {
        return null;
    }
}

You can also choose not to use parseDate function. In this case the date will be saved as string format like "2016-10-06" instead of Date type (I haven't tried whether this has negative consequences when manipulating the data or saving to database for example).

回答3:

In your component

let today: Date;

ngOnInit() {
  this.today = new Date().toISOString().split('T')[0];
}

and in your html

<input name="date" [(ngModel)]="today" type="date" required>

回答4:

Angular 2 completely ignores type=date. If you change type to text you'll see that your input has two-way binding.

<input type='text' #myDate [(ngModel)]='demoUser.date'/><br>

Here is pretty bad advise with better one to follow:

My project originally used jQuery. So, I'm using jQuery datepicker for now, hoping that angular team will fix the original issue. Also it's a better replacement because it has cross-browser support. FYI, input=date doesn't work in Firefox.

Good advise: There are few pretty good Angular2 datepickers:

• https://github.com/emirdeliz/meus-projetos/tree/master/angular2-schedule/app/frontend/components/datepicker

• https://github.com/MrPardeep/Angular2-DatePicker

• https://www.npmjs.com/package/ng2-datepicker

回答5:

In .ts :

today: Date;

constructor() {  

    this.today =new Date();
}

.html:

<input type="date"  
       [ngModel]="today | date:'yyyy-MM-dd'"  
       (ngModelChange)="today = $event"    
       name="dt" 
       class="form-control form-control-rounded" #searchDate 
>

回答6:

As per HTML5, you can use input type="datetime-local" instead of input type="date".

It will allow the [(ngModel)] directive to read and write value from input control.

Note: If the date string contains 'Z' then to implement above solution, you need to trim the 'Z' character from date.

For more details, please go through this link on mozilla docs.

回答7:

If you are using a modern browser there's a simple solution.

First, attach a template variable to the input.

<input type="date" #date />

Then pass the variable into your receiving method.

<button (click)="submit(date)"></button>

In your controller just accept the parameter as type HTMLInputElement and use the method valueAsDate on the HTMLInputElement.

submit(date: HTMLInputElement){
    console.log(date.valueAsDate);
}

You can then manipulate the date anyway you would a normal date.

You can also set the value of your <input [value]= "..."> as you would normally.

Personally, as someone trying to stay true to the unidirectional data flow, i try to stay away from two way data binding in my components.

回答8:

use DatePipe

> // ts file

import { DatePipe } from '@angular/common';

@Component({
....
providers:[DatePipe]
})

export class FormComponent {

constructor(private datePipe : DatePipe){}

    demoUser = new User(0, '', '', '', '', this.datePipe.transform(new Date(), 'yyyy-MM-dd'), '', 0, [], []);  
}

回答9:

you can use a workaround, like this:

<input type='date' (keyup)="0" #myDate [(ngModel)]='demoUser.date'/><br>

on your component :

 @Input public date: Date,