String

The String rule confirms that a field's value is a genuine string — a basic type check with no assumptions about length, format, or content. It's a lightweight guard for fields like a free-text comment, a display name, or a note field, wherever the requirement is simply that the input isn't a number, an array, or an object masquerading as text. Since it only checks type, pair it with rules like Min, Max, Alpha, or Regex whenever the field also needs a length constraint or a specific character format.

#Directive Code Snippet

<!DOCTYPE html> 
<html lang="en"> 
    ...
    <form (ngSubmit)="onSubmit(form)" #form="ngForm">
		<input string type="text" name="<name>" [(ngModel)]="<name>" #<name>="ngModel">
        <ng-absolute-validator [formInstance]="<name>"></ng-absolute-validator>
	</form>
    ...
</html>

#Chain Rule Code Snippet

<!DOCTYPE html> 
<html lang="en"> 
    ...
    <form (ngSubmit)="onSubmit(form)" #form="ngForm">
		<input rule="string" type="text" name="<name>" [(ngModel)]="<name>" #<name>="ngModel">
        <ng-absolute-validator [formInstance]="<name>"></ng-absolute-validator>
	</form>
    ...
</html>

#Reactive Form Code Snippet

//component.ts 
export class ReactiveComponent{

	public form  !: FormGroup;

  	constructor(
      	private fb : FormBuilder,
		private rv : ReactiveValidator,
	){this.generteForm()}

	generteForm(){
		this.form = this.fb.group({
			<name> : ['',this.rv.map('string',<CUSTOM_MESSAGE>)]
		})
	}
}

//component.html 
<!DOCTYPE html> 
<html lang="en"> 
    ...
    <form [formGroup]="form">
		<input type="text" name="<name>" formControlName="<name>">
        <ng-absolute-validator [formInstance]="form.get(<name>)"></ng-absolute-validator>
	</form>
    ...
</html>