I propose a fix in TypeScript definition files from:
class DropDownList extends kendo.ui.Widget { static fn: DropDownList; options: DropDownListOptions; dataSource: kendo.data.DataSource; span: JQuery; filterInput: JQuery; list: JQuery; ul: JQuery; element: JQuery; wrapper: JQuery; static extend(proto: Object): DropDownList; constructor(element: Element, options?: DropDownListOptions); close(): void; dataItem(index?: JQuery): any; dataItem(index?: number): any; destroy(): void; focus(): void; items(): any; enable(enable: boolean): void; open(): void; readonly(readonly: boolean): void; refresh(): void; search(word: string): void; select(): number; select(li: JQuery): void; select(li: number): void; select(li: Function): void; setDataSource(dataSource: kendo.data.DataSource): void; text(): string; text(text: string): void; toggle(toggle: boolean): void; value(): string; value(value: string): void; }to:
class DataBoundWidget extends Widget{ dataSource: kendo.data.DataSource; //or where it should be}class List extends DataBoundWidget{ dataItem(index?: JQuery): any; //or where it should be dataItem(index?: number): any; //or where it should be}class Select extends List{ setDataSource(dataSource: kendo.data.DataSource): void; //or where it should be}class DropDownList extends Select{ static fn: DropDownList; options: DropDownListOptions; span: JQuery; filterInput: JQuery; list: JQuery; ul: JQuery; element: JQuery; wrapper: JQuery; static extend(proto: Object): DropDownList; constructor(element: Element, options?: DropDownListOptions); close(): void; destroy(): void; focus(): void; items(): any; enable(enable: boolean): void; open(): void; readonly(readonly: boolean): void; refresh(): void; search(word: string): void; select(): number; select(li: JQuery): void; select(li: number): void; select(li: Function): void; text(): string; text(text: string): void; toggle(toggle: boolean): void; value(): string; value(value: string): void;}This should make sense, since all widgets does not inherits from kendo.ui.widget as your kendo.all.d.ts file defines.
I need a type for variable that lists all widgets that implements dataSource property. I don't want to write:
functionmyFunction(implementDataSource: kendo.ui.ListView | kendo.ui.DropDownList | kendo.ui.ComboBox | kendo.ui.Grid | kendo.ui...){ implementsDataSource.dataSource.data(something);}