CODEWITHSUNDEEP
javascripttypescripttypescript2.0
user5809117
user5809117

Reputation:

TS2511: Cannot create an instance of the abstract class 'Validator'

I'm new to TypeScript.

How come I get this error message?

I don't intend to initialize abstract class. I intend to initialize a concrete class that is IsEmptyValidator in validatorMap dictionary.

TS2511: Cannot create an instance of the abstract class 'Validator'

interface Dictionary<T> {
    [key: string]: T;
}

abstract class Validator {
    constructor() {
        console.log("super");
    }
}

class IsEmptyValidator extends Validator {
    public validate() {}

    constructor(){
        super();
        console.log("isEmpty");
    }
}

class ValidatorFactory {
    private validatorMap: Dictionary<Validator> = {
        "isEmpty": IsEmptyValidator
    };

    constructor() { }

    public create(validatorType: string) {
        let validatorToCreate: Validator = new this.validatorMap[validatorType];

        return validatorToCreate;
    }
}

Upvotes: 6

Views: 6955

Answers (1)

Nitzan Tomer
Nitzan Tomer

Reputation: 164147

Your dictionary doesn't have instances Validator but classes of it, so you should do this:

type ValidatorConstructor = {
    new (): Validator;
}

class ValidatorFactory {
    private validatorMap: Dictionary<ValidatorConstructor> = {
        "isEmpty": IsEmptyValidator
    };

    constructor() {}

    public create(validatorType: string) {
        let validatorToCreate: Validator = new this.validatorMap[validatorType]();

        return validatorToCreate;
    }
}

Upvotes: 10

Related Questions