On an Angular 12 application I created the following extension:
declare global {
interface String {
toNumber(): number | null;
}
}
Object.defineProperty(String.prototype, "toNumber", {
value: function(this: string) {
return Number(this) || null;
}
});
When using in an Angular's component:
var number = stringValue.toNumber();
I get the error:
Property 'toNumber' does not exist on type 'string'.
What is the best way to use such extensions in Angular?
Do I need to change the way I am creating the extension?
You can achieve that like the following:
src folder create global.d.ts file to define the signature of the extension method, with the following content:declare global {
interface String {
toNumber(): number | null;
}
}
export {}; // to define this file as a module
string.extension.ts anywhere under src folder, with the following content:Object.defineProperty(String.prototype, "toNumber", {
value: function(this: string) {
return Number(this) || null;
}
});
export {}; // to define this file as a module
string.extension.ts file in app.module.ts: import 'PATH_TO_YOUR_FILE/string-extension'