Error - Property 'appDateCompare' has no initializer

Ramco Ramco

I am getting error - Property 'appDateCompare' has no initializer and is not definitely assigned in the constructor.

@Directive({
  selector: '[appDateCompare]',
  standalone: true,
  providers: [
    {
      provide: NG_VALIDATORS,
      useExisting: DateCompareDirective,
      multi: true
    }
  ]
})
export class DateCompareDirective implements Validator {
  @Input('appDateComparison') appDateCompare: string; // FormControlName for DOB

  validate(control: AbstractControl): ValidationErrors | null {
    const dtStart0 = control.root.get(this.appDateCompare);

    if (!dtStart0 || !dtStart0.value || !control.value) {
      return null;
    }

    const dtStart = new Date(dtStart0.value);
    const dtEnd = new Date(control.value);

    if (dtEnd <= dtStart) {
      return { 'dateComparison': true }; 
    }

    return null; 
  }
}


  
      Start Date
      
      
      

    
   


  End Date
  
  
  
  @if (sessionForm.get('endDate')?.hasError('required')|| sessionForm.get('endDate')?.touched) {
    
      {{displayErrMessage.required}}
    
    }

Thanks

1 Reply

Know the answer? Post it — somebody with the same question will find it here.

Jayraj Chhaya2y ago
To resolve the "Property 'appDateCompare' has no initializer" error in your Angular directive, you need to ensure that the property appDateCompare is initialized in the constructor or assigned a default value. Here's how you can modify your DateCompareDirective class:
```
export class DateCompareDirective implements Validator {
  @Input('appDateComparison') appDateCompare: string = ''; // Initialize with a default value

  constructor() {
    // Initialize the property in the constructor if needed
    this.appDateCompare = 'default value';
  }

  // Rest of your directive code
}
```
By providing an initializer for the appDateCompare property, you can avoid the error and ensure that the property is properly initialized when the directive is used.