I'm writing a program using TypeScript. The problem is I implemented HTMLElement interface.
export class IEElement implements HTMLElement {
// something here
}
The compiler shows many errors that I have some properties missing (IEElement declares an interface but does not implement it). I have implemented about 5 properties that I need to. The rest is redundant. How to avoid errors? Do I need to implement all the interface members?
Yes, you need to implement all non-optional interface members.
The interface is a contract, if you have a class that implements that contract you are promising to implement everything in that contract.
The HTMLElement interface has a lot to implement - but if you just want to add a bit of behaviour, perhaps you could start with an existing implementation...
interface SpecialElement extends HTMLElement {
myCustomFunction: () => void;
}
var element = <SpecialElement>document.getElementById('example');
element.myCustomFunction = function () { };
