Value TypeScript definition files update

[Seyfor]

I think you should fix value when getting date value to return Date | null:

class DatePicker extends kendo.ui.Widget {

    static fn: DatePicker;

    options: DatePickerOptions;


    element: JQuery;
    wrapper: JQuery;

    static extend(proto: Object): DatePicker;

    constructor(element: Element, options?: DatePickerOptions);


    close(): void;
    destroy(): void;
    enable(enable: boolean): void;
    readonly(readonly: boolean): void;
    max(): Date;
    max(value: Date): void;
    max(value: string): void;
    min(): Date;
    min(value: Date): void;
    min(value: string): void;
    open(): void;
    setOptions(options: any): void;
    value(): Date;                  //!!! OR null
    value(value: Date): void;
    value(value: string): void;

}

[Seyfor]

And also for set:

value(): Date | null;
value(value: Date | null): void;
value(value: string | null): void;

[Dimiter Topalov]

Hello ,

Thank you for the observations and the suggestion, but null, returned from a method with return type of Date is valid TypeScript. For example:

https://www.typescriptlang.org/play/index.html 

Change the greet() function return type to Date, and return null, e.g.: 

greet():Date {
return null; // no TypeScript warning
    }

Let us know if you have other questions or comments, regarding Kendo UI.

Regards,
Dimiter Topalov
Telerik by Progress

[Seyfor]

This is not true.

get value(): Date
{
    return null;
}

raise error on build:

ErrorBuild:Type 'null' is not assignable to type 'Date'.

You can check it in Visual studio 15 preview 4 with this tsconfig.json options:

{
  "compilerOptions": {
    "module": "amd",
    "noEmitOnError": true,
    "noImplicitAny": true,
    "removeComments": true,
    "sourceMap": true,
    "strictNullChecks": true,
    "target": "es6",
    "experimentalDecorators": true
  },
    "exclude": [
        "node_modules",
        "wwwroot"
    ]
}

[Dimiter Topalov]

Hi Matjaž,

The described behavior occurs with strictNullChecks enabled only. We do not fully support all possible compiler options and TypeScript versions, but I have logged an issue in our GitHub repository, based on the provided information, and you can expect the updated definitions in a future release:

https://github.com/telerik/kendo-ui-core/issues/2312

Meanwhile disabling the strictNullChecks should prevent the described error.

Regards,
Dimiter Topalov
Telerik by Progress