Most likely you need to download and include the TypeScript declaration file for jQuery—jquery.d.ts—in your project. Option 1: Install the @types package (Recommended for TS 2.0+) In the same folder as your package.json file, run the following command: npm install –save-dev @types/jquery Then the compiler will resolve the definitions for jquery automatically. Option 2: Download … Read more
Here is the simplest solution w/o Service nor Observer: Put the global variables in a file an export them. // // ===== File globals.ts // ‘use strict’; export const sep=”https://stackoverflow.com/”; export const version: string=”22.2.2″; To use globals in another file use an import statement: import * as myGlobals from ‘globals’; Example: // // ===== File … Read more
You can create a reference to the enum in your component class (I just changed the initial character to be lower-case) and then use that reference from the template (plunker): import {Component} from ‘angular2/core’; enum CellType {Text, Placeholder} class Cell { constructor(public text: string, public type: CellType) {} } @Component({ selector: ‘my-app’, template: ` <div … Read more
EDIT As of TypeScript 2.8 this is officially possible with ReturnType<T>. type T10 = ReturnType<() => string>; // string type T11 = ReturnType<(s: string) => void>; // void type T12 = ReturnType<(<T>() => T)>; // {} type T13 = ReturnType<(<T extends U, U extends number[]>() => T)>; // number[] See this pull request to Microsoft/TypeScript … Read more
Caveats Here are two worthy caveats from the comments. Either you want user to be of type User | {} or Partial<User>, or you need to redefine the User type to allow an empty object. Right now, the compiler is correctly telling you that user is not a User. – jcalz I don’t think this … Read more
You need to import the map operator: import ‘rxjs/add/operator/map’
This is known as a const assertion. A const assertion tells the compiler to infer the narrowest* or most specific type it can for an expression. If you leave it off, the compiler will use its default type inference behavior, which will possibly result in a wider or more general type. Note that it is … Read more
Typescript now comes with a predefined Parameters<F> type alias in the standard library which is almost the same as ArgumentTypes<> below, so you can just use that instead of creating your own type alias. type TestParams = Parameters<(a: string, b: number) => void> // [string, number] Then to get for example the second parameter’s type … Read more
Construct signatures in interfaces are not implementable in classes; they’re only for defining existing JS APIs that define a ‘new’-able function. Here’s an example involving interfaces new signatures that does work: interface ComesFromString { name: string; } interface StringConstructable { new(n: string): ComesFromString; } class MadeFromString implements ComesFromString { constructor (public name: string) { console.log(‘ctor … Read more
Follow @Duncan’s @Bartvds’s answer, here to provide a workable way after years passed. At this point after Typescript 1.5 released (@Jun 15 ’15), your helpful interface interface MyType { instanceMethod(); } interface MyTypeStatic { new():MyType; staticMethod(); } can be implemented this way with the help of decorator. /* class decorator */ function staticImplements<T>() { return … Read more