Guide on assigning JSON response values to TypeScript variables in Angular 4

Question

Guide on assigning JSON response values to TypeScript variables in Angular 4

I'm just starting with Angular 4 and I'm attempting to retrieve a JSON value using http.post.

The response I'm receiving is: {"status":"SUCCESS"}

component

onSubmit(value: any) {
  console.log("POST");
  let url = `${this.posts_Url}`;
  this.http.post(url, value)
    .subscribe(resBody => {
        this.model.authstatus = resBody.json();
        console.log("Values====="+this.model.authstatus);
    });
}

Currently, when I try to assign the value, it ends up displaying as Values====={"status":"Failure"}

Is there a way for me to set the value like

this.model.authstatus = 'Failure'

javascript json angular typescript

Answer 1

Answer №1

submitForm(data: any) {
    console.log("Sending POST request");
    let apiUrl = `${this.postApiUrl}`;
    this.http.post(apiUrl, data)
      .subscribe(response => {
        this.model.authStatus = response.json().Status;
        console.log("Returned value====="+this.model.authStatus);
      });
}

This function will display Returned value===== 'Failure' in the console

Answer 2

submitForm(data: any) {
    console.log("Sending POST request");
    let apiUrl = `${this.postApiUrl}`;
    this.http.post(apiUrl, data)
      .subscribe(response => {
        this.model.authStatus = response.json().Status;
        console.log("Returned value====="+this.model.authStatus);
      });
}

This function will display Returned value===== 'Failure' in the console

Answer 3

Answer №2

this.http.post sends an asynchronous request, so if you try to log this.model.authstatus immediately after, it will likely be empty.

To display the correct data, you should log the value during the request itself like this:

this.http.post(url, value).subscribe(resBody => {
    this.model.authstatus = resBody.json
    console.log("Received Values: " + this.model.authstatus);
});

Answer 4

this.http.post sends an asynchronous request, so if you try to log this.model.authstatus immediately after, it will likely be empty.

To display the correct data, you should log the value during the request itself like this:

this.http.post(url, value).subscribe(resBody => {
    this.model.authstatus = resBody.json
    console.log("Received Values: " + this.model.authstatus);
});

Answer 5

Answer №3

If you want to `console.log` the result of an asynchronous call before the request is complete, you need to make sure your code is structured correctly.

onSubmit(value: any) {
   console.log("POST");
    let url = `${this.posts_Url}`;
    this.http.post(url, value).subscribe(resBody => this.model.authstatus = resBody.json); // This will happen after the request is finished, ~100ms later
    console.log("Values====="+this.model.authstatus); //This will happen right now, when this.model.authstatus is still undefined
  }

To correct this issue, you can simply move your `console.log` inside the http call subscription:

this.http.post(url, value).subscribe(resBody => {
    this.model.authstatus = resBody.json();
    console.log(this.model.authstatus);
});

Answer 6

If you want to `console.log` the result of an asynchronous call before the request is complete, you need to make sure your code is structured correctly.

onSubmit(value: any) {
   console.log("POST");
    let url = `${this.posts_Url}`;
    this.http.post(url, value).subscribe(resBody => this.model.authstatus = resBody.json); // This will happen after the request is finished, ~100ms later
    console.log("Values====="+this.model.authstatus); //This will happen right now, when this.model.authstatus is still undefined
  }

To correct this issue, you can simply move your `console.log` inside the http call subscription:

this.http.post(url, value).subscribe(resBody => {
    this.model.authstatus = resBody.json();
    console.log(this.model.authstatus);
});

Answer 7

Answer №4

By making an asynchronous call in your code, it will not wait for the response before moving on to the next line. That's why you should place the console.log() inside the subscribe method, as this is where the inner function gets triggered once the response is received.

onSubmit(data: any) {
    console.log("Sending a POST request");
    let url = `${this.posts_Url}`;
    this.http.post(url, data)
        .subscribe(response => {
            this.model.authstatus = response.json;
            console.log("Received values====="+this.model.authstatus);
    });

Answer 8

By making an asynchronous call in your code, it will not wait for the response before moving on to the next line. That's why you should place the console.log() inside the subscribe method, as this is where the inner function gets triggered once the response is received.

onSubmit(data: any) {
    console.log("Sending a POST request");
    let url = `${this.posts_Url}`;
    this.http.post(url, data)
        .subscribe(response => {
            this.model.authstatus = response.json;
            console.log("Received values====="+this.model.authstatus);
    });

Answer 9

Answer №5

Note: If you are receiving a {"status":"Failure"} in the response JSON, you can assign the status to this.model.authstatus using the following code:

this.http.post(url, value).
   subscribe((resBody:any) => {
   this.model.authstatus = resBody.json().status;
   console.log(this.model.authstatus);
   }
);

Answer 10

Note: If you are receiving a {"status":"Failure"} in the response JSON, you can assign the status to this.model.authstatus using the following code:

this.http.post(url, value).
   subscribe((resBody:any) => {
   this.model.authstatus = resBody.json().status;
   console.log(this.model.authstatus);
   }
);

Answer 11

Answer №6

When sending a POST request to the specified URL with a given value, the code subscribes to the response body returned and assigns it to 'resBody'. The 'authstatus' property of the model is then set to the JSON representation of the response body, which is logged to the console. Finally, the function returns the 'authstatus' property of the model.

Answer 12

When sending a POST request to the specified URL with a given value, the code subscribes to the response body returned and assigns it to 'resBody'. The 'authstatus' property of the model is then set to the JSON representation of the response body, which is logged to the console. Finally, the function returns the 'authstatus' property of the model.

Guide on assigning JSON response values to TypeScript variables in Angular 4

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

Answer №6

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