检索 Post Request 响应并存储到 angular 8 中的变量中

Question

I am using the Face Recognition and Face Detection api by lambda and am supposed to get a response from the api using post. Usually for getting responses I use get while for sending responses I use post. How do I get this response using post so I can tell whether the image has been recognized or not? My code is below:

Node.js file

facedetAPIRoutes.route("/").post(function (req, res){
    let imageUrl = req.body.url;
    myFaceDetAPI.recognizeImg(imageUrl);
});

Service file

sendImage(imgUrl){
    console.log(imgUrl);
    const obj = {
      url: imgUrl
    };    

    this.http.post(`${this.uri}`, obj)
      .subscribe(res => {
        console.log("this is res: " + res);
        console.log('image sent to api done');
      });
  }

Component file

public handleImage(webcamImage: WebcamImage): void {
    console.info("received webcam image", webcamImage);
    this.webcamImage = webcamImage;
    console.log("this is: " + this.webcamImage.imageAsDataUrl);
    //this.fda.sendImage(this.webcamImage.imageAsDataUrl);
    this.fda.sendImage("http://localhost:4000/uploads/1570563000257-arnold4.jpg");
  }

Answer 1

Hellow. You can use STATUS CODE of response. 200 status code is success status for operation. or if error it sent you status code 4xx. You can read more about status code https://en.wikipedia.org/wiki/List_of_HTTP_status_codes

Answer 2

Apparently it was a problem in my backend file. For this I simply used res.status. That way I was able to use subscribe in my service file.

Node.js

facedetAPIRoutes.route("/").post(function (req, res){
    let imageUrl = req.body.url;
    res.status(200).json(myFaceDetAPI.recognizeImg(imageUrl));
});

Service File

 sendImage(imgUrl){
    console.log(imgUrl);
    const obj = {
      url: imgUrl
    };    

    this.http.post(`${this.uri}`, obj)
      .subscribe(res => {
        console.log("this is res: " + JSON.stringify(res));
        console.log('image sent to api done');
      });
  }