Different property 'responseType' types are not compatible

Question

Different property 'responseType' types are not compatible

Having trouble making a POST request in Angular 5 that accepts text/plain as a response. The method being called in Angular expects a JSON response, causing an error when trying to parse the response.

Attempted to call the method with parameter {responseType: 'text'}, but encountering errors in VS code and the console during compilation of the application.

Here is the Angular 5 code for a POST request expecting a response as text/plain.

this.http
.post<string>(this.loginUrl, this.user, {responseType: 'text'}) // error in this line
.subscribe(
    (data) => this.success(data),
    (error) => this.failure(error)
);

Upon compilation, the following error appears in the console:

ERROR in src/app/login/login.component.ts(47,47): error TS2345: Argument of type '{ responseType: "text"; }' is not assignable to parameter of type '{ headers?: HttpHeaders | { [header: string]: string | string[]; }; observe?: "body"; params?: Ht...'.
  Types of property 'responseType' are incompatible.
    Type '"text"' is not assignable to type '"json"'.

angular typescript

Answer 1

Answer №1

The `post` function's acceptance of `responseType:'text'` lacks generality, as the output type is already specified (i.e., `string`).

this.http
.post(this.loginUrl, this.user, {responseType: 'text'}) // no generic parameter
.subscribe(
    (data) => this.success(data), // data is string
    (error) => this.failure(error)
);

Answer 2

The `post` function's acceptance of `responseType:'text'` lacks generality, as the output type is already specified (i.e., `string`).

this.http
.post(this.loginUrl, this.user, {responseType: 'text'}) // no generic parameter
.subscribe(
    (data) => this.success(data), // data is string
    (error) => this.failure(error)
);

Answer 3

Answer №2

Here is an alternative method if you prefer not to eliminate <string> in order to maintain strong typing in your response:

    const httpOptions = {
      headers: new HttpHeaders({
        'Accept': 'text/plain, */*',
        'Content-Type': 'application/json' // Sending JSON data
      }),
      responseType: 'text' as 'json'  // Expecting plain text as the response type.
    };
    return this.http.post<string>(this.setBaseUrl, body, httpOptions);

Substitute the value of text with a appropriate responseType based on the data format that you want to retrieve.

Answer 4

Here is an alternative method if you prefer not to eliminate <string> in order to maintain strong typing in your response:

    const httpOptions = {
      headers: new HttpHeaders({
        'Accept': 'text/plain, */*',
        'Content-Type': 'application/json' // Sending JSON data
      }),
      responseType: 'text' as 'json'  // Expecting plain text as the response type.
    };
    return this.http.post<string>(this.setBaseUrl, body, httpOptions);

Substitute the value of text with a appropriate responseType based on the data format that you want to retrieve.

Answer 5

Answer №3

To improve your request, simply exclude the "string". You can use the following code snippet:

this.httpClient.post(this.loginEndpoint, this.userData, {responseType: 'text'}).subscribe(
    (responseData) => this.handleSuccess(responseData),
    (error) => this.handleError(error)
);

Answer 6

To improve your request, simply exclude the "string". You can use the following code snippet:

this.httpClient.post(this.loginEndpoint, this.userData, {responseType: 'text'}).subscribe(
    (responseData) => this.handleSuccess(responseData),
    (error) => this.handleError(error)
);

Answer 7

Answer №4

Today, I encountered this issue firsthand. After a brief search, I discovered that the responseType option may actually exist. By implementing it as shown below, I was able to resolve the problem:

let requestOptions: Object = { 
    headers: new HttpHeaders().set('Authorization', 'Basic ' + credentials),
    responseType: 'text'
}    

return this.httpClient.get<any>(
                this.environment.tokenHost + this.environment.authenticationURL,
                requestOptions
            )
            .subscribe(result => {
                // do stuff
            });

Implementing the responseType in this manner made a difference, compared to setting it within the request itself.

Best regards.

Answer 8

Today, I encountered this issue firsthand. After a brief search, I discovered that the responseType option may actually exist. By implementing it as shown below, I was able to resolve the problem:

let requestOptions: Object = { 
    headers: new HttpHeaders().set('Authorization', 'Basic ' + credentials),
    responseType: 'text'
}    

return this.httpClient.get<any>(
                this.environment.tokenHost + this.environment.authenticationURL,
                requestOptions
            )
            .subscribe(result => {
                // do stuff
            });

Implementing the responseType in this manner made a difference, compared to setting it within the request itself.

Best regards.

Answer 9

Answer №5

When dealing with HTTP requests in Angular, it's common practice to define the headers separately as shown below:

Edit

Interestingly, creating a header object outside of the post request might lead to unexpected errors, which can be resolved by passing the headers inline within the post request itself.

let headerOptions = {
 headers: new HttpHeaders(
     {'content-type':'application/json'}),
       responseType:'text'
 }
this.http.post(this.loginUrl,this.user, headerOptions)
 .subscribe((r)=>{console.log(r)})

This approach of including the entire headers object directly within the post request can help avoid compilation errors and streamline the code structure.

Answer 10

When dealing with HTTP requests in Angular, it's common practice to define the headers separately as shown below:

Edit

Interestingly, creating a header object outside of the post request might lead to unexpected errors, which can be resolved by passing the headers inline within the post request itself.

let headerOptions = {
 headers: new HttpHeaders(
     {'content-type':'application/json'}),
       responseType:'text'
 }
this.http.post(this.loginUrl,this.user, headerOptions)
 .subscribe((r)=>{console.log(r)})

This approach of including the entire headers object directly within the post request can help avoid compilation errors and streamline the code structure.

Different property 'responseType' types are not compatible

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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