Adding existing functions in TypeScript: Node.getAttribute()

问题

What is the best way to add a function to typescript that actually exists already? In my case this is Node.getAttribute(), which is actually built-in to the browser, but not yet recognized by TypeScript. It errors: Cannot find property 'getAttribute' on type 'Node'.

In my case I ran into this error executing the following:

var xmlDocument = new DOMParser().parseFromString(xmlString, "text/xml"),
    rootfile    = xmlDocument.getElementsByTagName("aNode")[0];

console.log(rootfile.getAttribute("anAttribute"));

This succeeds in the browser, but throws an error by TypeScript.

回答1:

Since interfaces are open ended just tell typescript about it:

interface Node {
    getAttribute(attr: string): string;
}

I recommend doing this in a globals.d.ts file at the root of your project.

回答2:

You should look for the d.ts files for Node at definitely typed https://github.com/borisyankov/DefinitelyTyped That would be easier than rewriting the whole node definitions by hand...

来源：https://stackoverflow.com/questions/30429520/adding-existing-functions-in-typescript-node-getattribute