mapcomplete/UI/Base/AsyncLazy.ts

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851 B
TypeScript

import BaseUIElement from "../BaseUIElement";
import {VariableUiElement} from "./VariableUIElement";
import {UIEventSource} from "../../Logic/UIEventSource";
import Loading from "./Loading";
export default class AsyncLazy extends BaseUIElement{
private readonly _f: () => Promise<BaseUIElement>;
constructor(f: () => Promise<BaseUIElement>) {
super();
this._f = f;
}
protected InnerConstructElement(): HTMLElement {
// The caching of the BaseUIElement will guarantee that _f will only be called once
return new VariableUiElement(
UIEventSource.FromPromise(this._f()).map(el => {
if(el === undefined){
return new Loading()
}
return el
})
).ConstructElement()
}
}