Angular 7反应形式控件

Question

i made a simple website in angular 7 with reactive form control. It contains 2 input fields and 2 submit button, one is a simple test for prime factorization and one a leap-year test. The submit buttons are disabled till the user made the right input, a number.

I know this will be easy with template driven control but i am trying to learn reactive forms. I made 2 different form-groups and it works.

But know i want to make it with only 1 form-group. I searched the internet but found nothing about this. So my question:

Is it possible to make the 2 different tests with only 1 form-group? Would be easier if i will write more tests. Smaller code.

Thanks

My Code: HTML:

<div class="container">

  <form [formGroup]="primForm" (ngSubmit)="onSubmit(primForm.value)" novalidate>
    <div class="form-group">
      <h3>Primfaktoren</h3>
      <mat-form-field>
        <input matInput class="form-control" formControlName="zahl" placeholder="Zu prüfende Zahl">
      </mat-form-field>

      <button type="submit" [disabled]="primForm.pristine || primForm.invalid" class="btn btn-success">Zerlegen</button>

      <br>
      <div>Die Faktoren sind:

        <div style="display:inline" *ngFor="let faktor of faktoren">{{faktor}}  </div>
        <br>
      </div>
    </div>

  </form>

  <form [formGroup]="jahrForm" (ngSubmit)="onSubmit(jahrForm.value)" novalidate>
    <div class="form-group">
      <h3>Schaltjahrtest</h3>
      <mat-form-field>
        <input matInput class="form-control" formControlName="jahr" placeholder="Welches Jahr?">
      </mat-form-field>
      <button type="submit" [disabled]="jahrForm.pristine || jahrForm.invalid" class="btn btn-success">Prüfen</button>
      <div *ngIf="antwort">
        <p>{{jahrForm.value.jahr}} ist {{antwort}} Schaltjahr</p>
      </div>
    </div>

  </form>

</div>

TS:

import {Component} from '@angular/core';
import {FormBuilder, FormGroup, Validators} from '@angular/forms';

@Component({
  selector: 'app-algos',
  templateUrl: './algos.component.html',
  styleUrls: ['./algos.component.scss']
})
export class AlgosComponent {

  title = 'Mathematische Tests';

  primForm: FormGroup;
  jahrForm: FormGroup;

  submitted = false;
  help: number;
  ergebnis: number[];
  prf: string;

  faktoren = [];
  antwort: string;
  zahl: number;
  jahr: number;

  constructor(private fb: FormBuilder) {
    this.createForm();
  }

  createForm() {
    this.primForm = this.fb.group({
      zahl: ['', Validators.min(3)]
    });
    this.jahrForm = this.fb.group({
      jahr: ['', Validators.min(1)]
    });
  }

  onSubmit(object: Object) {

    const key = Object.keys(object);

    this.submitted = true;

    if (key[0] === 'zahl') {
      this.help = parseInt(object['zahl'], 10);
      this.ergebnis = this.primFaktor(this.help);
    } else {
      if (key[0] === 'jahr') {
        this.help = parseInt(object['jahr'], 10);
        this.prf = this.jahrTest(this.help);
      }
    }
  }

  primFaktor(zahl: number): number[] {

    this.faktoren = [];
    let index = 2;

    while (zahl !== 1) {
      if (zahl % index === 0) {
        this.faktoren.push(index);
        zahl /= index;
        index = 2;
      } else {
        index++;
      }
    }
    return this.faktoren;
  }

  jahrTest(jahr: number): string {
    this.antwort = '';

    if (jahr % 4 === 0 && (jahr % 100 !== 0 || jahr % 400 === 0)) {
      this.antwort = 'ein';
    } else {
      this.antwort = 'kein';
    }
    return this.antwort;
  }

}

Answer 1

You can put all your form in one formGroup

Create

this.primForm = new FormGroup(
{
    'zahl': new FormControl('', Validators.min(3)),
    'jahr': new FormControl('', [Validators.min(3), Validators.required])
});

Initialisation

this.primForm.setValue({
  zahl: this.someObject.someValue,
  jahr: this.someObject.someValueX
});

Validation

this.primForm.controls['zahl'].valid

Get Value

this.priForm.value.zah1

or

this.priForm.controls['zah1'].value

Happy coding !