Make sure to verify the status of ngmodel or forms to see if they are dirty or contain

Question

Make sure to verify the status of ngmodel or forms to see if they are dirty or contain

In Angular, how can I determine if ngModel or form fields are dirty or have input without using formgroup?

I need to check if at least 5 of the input fields have a value or are considered dirty in order to display a message. How can I achieve this for 5 fields from DealFields or ngModel dealDispositionFormFields? Thank you.

#tscode

    class DealDispositionFormFields {
      dealName:string;
      summary:string;
      dealDispositionType: string;
      terminationPayment:number;
      effectiveDate: string;
      totalBrokerCommission: number;
      effectiveDateString: string;
      dealId: number;
}
    
    @Component({
      selector: 'app-deal-idle-disposition',
      templateUrl: './deal-idle-disposition.component.html',
      styleUrls: ['./deal-idle-disposition.component.css']
    })
    export class DealIdleDispositionComponent implements OnInit {
           
             ngOnInit(): void {   
                this.dealDispositionFormFields = new DealDispositionFormFields();
              }
        
        checkIf5FieldsAreDirty() {
        ...
        }

#html code

<div id="deal-form-container" *ngIf="isEditing">
        <div id="deal-form-wizard-top" *ngIf="dealDispositionFormFields.dealDispositionType === 'Buyout'">
          <mat-form-field appearance="fill">
            <mat-label>Deal Name</mat-label>
            <input 
              matInput
              [(ngModel)]="dealDispositionFormFields.dealName"
              [required]="isExistingDeal">
          </mat-form-field>
          <mat-form-field appearance="fill">
            <mat-label>Summary of Deal</mat-label>
            <textarea 
              matInput
              class="resize-none"
              [(ngModel)]="dealDispositionFormFields.summary"
              [rows]="5"
              [required]="isExistingDeal">
            </textarea>
          </mat-form-field>
          <mat-form-field appearance="fill">
            <mat-label>Termination Payment</mat-label>
            <input 
              matInput
              (keyup) = "computeBuyout()"
              mask="separator.0" 
              thousandSeparator=","
              [allowNegativeNumbers]="false"
              [(ngModel)]="dealDispositionFormFields.terminationPayment"
              [required]="isExistingDeal">
              <span matPrefix *ngIf="dealDispositionFormFields.terminationPayment">$</span>
          </mat-form-field>
          <mat-form-field appearance="fill">
            <mat-label>Effective Date</mat-label>
              <input matInput
                (dateChange)="computeBuyout()"
                [matDatepicker]="effectiveDate" 
                [(ngModel)]="dealDispositionFormFields.effectiveDate"
                [required]="isExistingDeal">
              <mat-datepicker-toggle matSuffix [for]="effectiveDate"></mat-datepicker-toggle>
              <mat-datepicker #effectiveDate></mat-datepicker>
          </mat-form-field>
          <mat-form-field appearance="fill">
            <mat-label>Total Broker Commission</mat-label>
            <input 
              matInput
              (keyup) = "computeBuyout()"         
              mask="separator.0" 
              thousandSeparator=","
              [allowNegativeNumbers]="false"
              [(ngModel)]="dealDispositionFormFields.totalBrokerCommission"
              [required]="isExistingDeal">
              <span matPrefix *ngIf="dealDispositionFormFields.totalBrokerCommission">$</span>
          </mat-form-field>
        </div>
      </div>

angular typescript angular-material

Answer 1

Answer №1

When working with ngModel, it's worth noting the dirty property as highlighted in this helpful response

To monitor changes, you can utilize the change or ngModelChange events on your inputs.

For instance, within your code snippet:

HTML

<mat-form-field appearance="fill">
            <mat-label>Deal Name</mat-label>
            <input 
              matInput
              [(ngModel)]="dealDispositionFormFields.dealName"
              [required]="isExistingDeal"
              (change)="checkIfDirty()">
</mat-form-field>

TS

   checkIfDirty() {
    let countDirtyValues = 0;
    Object.values(this.dealDispositionFormFields).map(value => {
      if (value) {
        countDirtyValues += 1;
      }
    });
    if (countDirtyValues >= 5) {
      // do something here
    }
  }

If seeking an alternative approach, consider that ngmodel is essentially a formControl instance. In such cases, opting for a reactive form, as outlined in the Angular documentation for formControl here, could offer a solution without necessarily needing a formGroup.

Answer 2

When working with ngModel, it's worth noting the dirty property as highlighted in this helpful response

To monitor changes, you can utilize the change or ngModelChange events on your inputs.

For instance, within your code snippet:

HTML

<mat-form-field appearance="fill">
            <mat-label>Deal Name</mat-label>
            <input 
              matInput
              [(ngModel)]="dealDispositionFormFields.dealName"
              [required]="isExistingDeal"
              (change)="checkIfDirty()">
</mat-form-field>

TS

   checkIfDirty() {
    let countDirtyValues = 0;
    Object.values(this.dealDispositionFormFields).map(value => {
      if (value) {
        countDirtyValues += 1;
      }
    });
    if (countDirtyValues >= 5) {
      // do something here
    }
  }

If seeking an alternative approach, consider that ngmodel is essentially a formControl instance. In such cases, opting for a reactive form, as outlined in the Angular documentation for formControl here, could offer a solution without necessarily needing a formGroup.

Answer 3

Answer №2

If you're looking for a robust solution for form validation in Angular, Reactive Forms are the way to go. They offer comprehensive functionality and are more user-friendly.

For detailed instructions on using reactive forms, refer to the official guide at: https://angular.io/guide/reactive-forms

In your component, you can define a FormGroup with controls as shown below:

@Component({
      selector: 'app-deal-idle-disposition',
      templateUrl: './deal-idle-disposition.component.html',
      styleUrls: ['./deal-idle-disposition.component.css']
})
export MyComponent implements OnInit {
  myForm: FormGroup;
  constructor() {
    // create the form
    this.myForm = new FormGroup({
      name: new FormControl('', [Validators.required]),
      age: new FormControl(0, [Validators.required, Validators.min(18)])
    });
  }
}

The API docs (https://angular.io/api/forms/FormControl) indicate that the FormControl class inherits from AbstractControl, which includes the dirty flag field. You can assess a control's state using this property:

const nameControl = this.myForm.get('name'); // or this.myForm.controls['name'];
if (nameControl.dirty) {
  // ...
}

Furthermore, you can observe changes in the control's value, similar to ngModel:

nameControl.valueChanges.subscribe((newValue) => {
  // ...
});

Similarly, you can monitor status changes of the control using:

nameControl.statusChanges.subscribe((newStatus) => {
  // ...
});

Be sure to explore the official guide and API documentation to gain insights into Angular's framework.

Answer 4

If you're looking for a robust solution for form validation in Angular, Reactive Forms are the way to go. They offer comprehensive functionality and are more user-friendly.

For detailed instructions on using reactive forms, refer to the official guide at: https://angular.io/guide/reactive-forms

In your component, you can define a FormGroup with controls as shown below:

@Component({
      selector: 'app-deal-idle-disposition',
      templateUrl: './deal-idle-disposition.component.html',
      styleUrls: ['./deal-idle-disposition.component.css']
})
export MyComponent implements OnInit {
  myForm: FormGroup;
  constructor() {
    // create the form
    this.myForm = new FormGroup({
      name: new FormControl('', [Validators.required]),
      age: new FormControl(0, [Validators.required, Validators.min(18)])
    });
  }
}

The API docs (https://angular.io/api/forms/FormControl) indicate that the FormControl class inherits from AbstractControl, which includes the dirty flag field. You can assess a control's state using this property:

const nameControl = this.myForm.get('name'); // or this.myForm.controls['name'];
if (nameControl.dirty) {
  // ...
}

Furthermore, you can observe changes in the control's value, similar to ngModel:

nameControl.valueChanges.subscribe((newValue) => {
  // ...
});

Similarly, you can monitor status changes of the control using:

nameControl.statusChanges.subscribe((newStatus) => {
  // ...
});

Be sure to explore the official guide and API documentation to gain insights into Angular's framework.

Make sure to verify the status of ngmodel or forms to see if they are dirty or contain

Answer №1

Answer №2

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