node.js - 如何以 Angular 循环多个http post请求？

Question

我有一组对象要传递到 mongoDB 模型，该模型一次接受一个对象，我尝试循环 http post 请求，但由于它是异步的，所以不起作用。还有其他解决方案吗？

for (let entry of ingredients) {
    const body = JSON.stringify(entry);
    console.log(body);
    const headers = new HttpHeaders({'Content-Type': 'application/json'});
    return this.http.post('http://localhost:3000/shopping-list', body, {headers: headers})
        .catch((error: Response) => Observable.throw(error));

}

谢谢

Answer 1

如果您想连续发出请求，请尝试 concatMap

Observable.from(ingredients)
    .concatMap(entry => this.http.post('http://localhost:3000/shopping-list', entry))
    .subscribe(
        response => console.log(response), //do something with responses
        error => console.error(error), // so something on error
        () => console.info("All requests done") // do something when all requests are done
    );