日期在 Angular 中没有约束力

Question

I am using Angular 7 for my Web app and have the following code in html:

<div class="form-group col-md-6">
    <label for="myDate">My Date</label>
    <div class="input-group">
        <input 
            class="form-control" 
            placeholder="yyyy/mm/dd" 
            id="myDate" 
            name="myDate"
            [ngModel]="project.myDate | date: 'yyyy/MM/dd'" 
            ngbDatepicker #d="ngbDatepicker" 
            tabindex="9">
        <div class="input-group-append">
            <button class="btn btn-outline-secondary calendar" (click)="d.toggle()" type="button"></button>
        </div>
    </div>
</div>

When calling a Web API I got a JSON object like this:

{
    "id": 11,
    "description": "This is a test description",
    "budget": 1000,
    "myDate": "2020/02/11",
    ...
}

This is the component code:

export class ProjectEditComponent implements OnInit {

    project: Project;
    errorMessage: string;


    constructor(private myprojectService: ProjectService) { }

    ngOnInit() {

        this.myprojectService.getDataById(this.dataId).subscribe(
            data => (this.project = data, console.log(JSON.stringify(data))),
            error => this.errorMessage = error as any,
        );

        console.log(this.errorMessage);
    }
}

All the properties are bind properly except myDate property.

I have doing some research and trying different propose solutions , but none one seems to work so far.

Does any one of you face something similar?

Answer 1

To make a two way binding, you should first make sure you have imported FormsModule into your @NgModule in app.module.ts .

app.module.ts:

import { BrowserModule } from "@angular/platform-browser";
import { NgModule } from "@angular/core";

import { AppComponent } from "./app.component";

//import this.
import { FormsModule } from "@angular/forms";

@NgModule({
  declarations: [AppComponent],
  imports: [BrowserModule, FormsModule], //register it
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule {}

Then, in html file use [(ngModel)] :

<div class="form-group col-md-6">
    <label for="myDate">My Date</label>
    <div class="input-group">
        <input 
            class="form-control" 
            placeholder="yyyy/mm/dd" 
            id="myDate" 
            name="myDate"
            [(ngModel)]="project.myDate" 
            ngbDatepicker #d="ngbDatepicker" 
            tabindex="9">
        <div class="input-group-append">
            <button class="btn btn-outline-secondary calendar" (click)="d.toggle()" type="button"></button>
        </div>
    </div>
</div>

I remove the pipe because using the two way bindind with it gave me error. check that thread for a workout.