如何等待一个变量在 Angular 中改变它的值？

Question

I have a variable which changes its value upon an HttpRequest is completed. Its value is false unless the HttpRequest is finished. Is it possible to use it in a conditional statement? So far I have tried:

async getAsyncValue() {
    const loading = await this.dataSource.loading$.toPromise();
    if (!loading) {
        // do something
    }
}

Answer 1

this.dataSource.loading$.subscribe((data) => {
    //do something
}

Assuming the loading$ is an observable. You don't really need to convert it to a promise.