Input type number “only numeric value” validation

Question

How can I validate an input of type=\"number\" to only be valid if the value is numeric or null using only Reactive Forms (no directives)?
Only numbers

Answer 1

The easiest way would be to use a library like this one and specifically you want noStrings to be true

    export class CustomValidator{   // Number only validation   
      static numeric(control: AbstractControl) {
        let val = control.value;

        const hasError = validate({val: val}, {val: {numericality: {noStrings: true}}});

        if (hasError) return null;

        return val;   
      } 
    }