Angular2 set value for formGroup

2019-03-11 15:22发布

问题:

So I have a complex form for creating an entity and I want to use it for editing as well I am using new angular forms API. I structured the form exactly as the data I retrieve from the database so I want to set the value of the whole form to the data retrieved here is an example to what i want to do:

this.form = builder.group({
      b : [ "", Validators.required ],
      c : [ "", Validators.required ],
      d : [ "" ],
      e : [ [] ],
      f : [ "" ]
    });
this.form.value({b:"data",c:"data",d:"data",e:["data1","data2"],f:data});

PS: NgModel doesn't work with new forms api also i don't mind using one way data binding in template as in

<input formControlName="d" value="[data.d]" />

that works but it would be a pain in case of the arrays

回答1:

To set all FormGroup values use, setValue:

this.myFormGroup.setValue({
  formControlName1: myValue1, 
  formControlName2: myValue2
});

To set only some values, use patchValue:

this.myFormGroup.patchValue({
  formControlName1: myValue1, 
  // formControlName2: myValue2 (can be omitted)
});

With this second technique, not all values need to be supplied and fields whos values were not set will not be affected.



回答2:

For set value when your control is FormGroup can use this example

this.clientForm.controls['location'].setValue({
      latitude: position.coords.latitude,
      longitude: position.coords.longitude
    });


回答3:

As pointed out in comments, this feature wasn't supported at the time this question was asked. This issue has been resolved in angular 2 rc5



回答4:

I have implemented a temporary solution until angular2 support form updateValue

 initFormGroup(form: FormGroup, data: any) {
        for(var key in form.controls) {
          console.log(key);
          if(form.controls[key] instanceof FormControl) {
            if(data[key]){
              let control = <FormControl>form.controls[key];
              this.initFormControl(control,data[key]);
            }
          } else if(form.controls[key] instanceof FormGroup) {
            if(data[key]){
              this.initFormGroup(<FormGroup>form.controls[key],data[key]);
            }
          } else if(form.controls[key] instanceof FormArray) {
            var control = <FormArray>form.controls[key];
            if(data[key])
            this.initFormArray(control, data[key]);
          }
        }
      }
      initFormArray(array: FormArray, data: Array<any>){
    if(data.length>0){
      var clone = array.controls[0];
      array.removeAt(0);
      for(var idx in data) {
        array.push(_.cloneDeep(clone));
        if(clone instanceof FormGroup)
          this.initFormGroup(<FormGroup>array.controls[idx], data[idx]);
        else if(clone instanceof FormControl)
          this.initFormControl(<FormControl>array.controls[idx], data[idx]);
        else if(clone instanceof FormArray)
          this.initFormArray(<FormArray>array.controls[idx], data[idx]);
      }
    }
  }


initFormControl(control: FormControl, value:any){
    control.updateValue(value);
  }

usage:

this.initFormGroup(this.form, {b:"data",c:"data",d:"data",e:["data1","data2"],f:data});

note: form and data must have the same structure and i have used lodash for deepcloning jQuery and other libs can do as well



回答5:

Yes you can use setValue to set value for edit/update purpose.

this.personalform.setValue({
      name: items.name,
      address: {
        city: items.address.city,
        country: items.address.country
      }
    });

You can refer http://musttoknow.com/use-angular-reactive-form-addinsert-update-data-using-setvalue-setpatch/ to understand how to use Reactive forms for add/edit feature by using setValue. It saved my time



回答6:

"NgModel doesn't work with new forms api".

That's not true. You just need to use it correctly. If you are using the reactive forms, the NgModel should be used in concert with the reactive directive. See the example in the source.

/*
 * @Component({
 *      selector: "login-comp",
 *      directives: [REACTIVE_FORM_DIRECTIVES],
 *      template: `
 *        <form [formGroup]="myForm" (submit)='onLogIn()'>
 *          Login <input type='text' formControlName='login' [(ngModel)]="credentials.login">
 *          Password <input type='password' formControlName='password'
 *                          [(ngModel)]="credentials.password">
 *          <button type='submit'>Log in!</button>
 *        </form>
 *      `})
 * class LoginComp {
 *  credentials: {login:string, password:string};
 *  myForm = new FormGroup({
 *    login: new Control(this.credentials.login),
 *    password: new Control(this.credentials.password)
 *  });
 *
 *  onLogIn(): void {
 *    // this.credentials.login === "some login"
 *    // this.credentials.password === "some password"
 *  }
 * }
 */

Though it looks like from the TODO comments, this will likely be removed and replaced with a reactive API.

// TODO(kara):  Replace ngModel with reactive API
@Input('ngModel') model: any;