I had a similar issue and thought I’d post in case someone else made the same mistake. First, one thing to consider is AfterViewInit; you need to wait for the view to be initialized before you can access your @ViewChild. However, my @ViewChild was still returning null. The problem was my *ngIf. The *ngIf directive … Read more
For versions of TypeScript at or above 3.5 In TypeScript 3.5, the Omit type was added to the standard library. See examples below for how to use it. For versions of TypeScript below 3.5 In TypeScript 2.8, the Exclude type was added to the standard library, which allows an omission type to be written simply … Read more
You are using the –noImplicitAny and TypeScript doesn’t know about the type of the Users object. In this case, you need to explicitly define the user type. Change this line: let user = Users.find(user => user.id === query); to this: let user = Users.find((user: any) => user.id === query); // use “any” or some other … Read more
It is supported since the release of TypeScript 1.6. The correct command is –init not init: $ tsc –init Try to run in your console the following to check the version: $ tsc -v If the version is older than 1.6 you will need to update: $ npm install -g typescript Remember that you need … Read more
When you overload in TypeScript, you only have one implementation with multiple signatures. class Foo { myMethod(a: string); myMethod(a: number); myMethod(a: number, b: string); myMethod(a: any, b?: string) { alert(a.toString()); } } Only the three overloads are recognized by TypeScript as possible signatures for a method call, not the actual implementation. In your case, I … Read more
Adding an index signature will let TypeScript know what the type should be. In your case that would be [key: string]: string; interface ISomeObject { firstKey: string; secondKey: string; thirdKey: string; [key: string]: string; } However, this also enforces all of the property types to match the index signature. Since all of the properties are … Read more
You have to use providers instead of injectables @Component({ selector: ‘my-app’, providers: [NameService] }) Complete code sample here.
You are better off using a native array instead of an object literal with number-like properties, so that numbering (as well as numerous other array functions) are taken care of off-the-shelf. What you are looking for here is an inline interface definition for your array that defines every element in that array, whether initially present … Read more
You can now simply npm install –save-dev ts-node nodemon and then run nodemon with a .ts file and it will Just Work: nodemon app.ts Previous versions: I was struggling with the same thing for my development environment until I noticed that nodemon‘s API allows us to change its default behaviour in order to execute a … Read more
Based on Tomasz Nurkiewiczs answer, the “problem” is that typescript is typesafe. 🙂 So the document.getElementById() returns the type HTMLElement which does not contain a value property. The subtype HTMLInputElement does however contain the value property. So a solution is to cast the result of getElementById() to HTMLInputElement like this: var inputValue = (<HTMLInputElement>document.getElementById(elementId)).value; <> … Read more