The type 'Observable<boolean>' cannot be assigned to type 'Observable<UserRegistration>'

Question

The type 'Observable<boolean>' cannot be assigned to type 'Observable<UserRegistration>'

function completeRegistration(email: string, password: string, firstName: string, lastName: string, location: string): Observable<UserDetails> {
    let body = JSON.stringify({ email, password, firstName, lastName,location });
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });

    return this.http.post(this.baseUrl + "/accounts", body, options)
      .map(res => true)
      .catch(this.handleError);
  }

While incorporating code I found online into my project, I encountered an issue. The error message displayed is:

Type 'Observable<boolean>' is not assignable to type 'Observable<UserDetails>'.
  Type 'boolean' is not assignable to type 'UserDetails'.

The code also references the following interface:

export interface UserDetails {
  email: string;
  password: string;
  firstName: string;
  lastName:  string;
  location: string;
}

angular typescript angular-http angular-httpclient angular-observable

Answer 1

Answer №1

After reviewing your code, it appears that you are currently returning a boolean value as true, even though the definition specifies that it should return

Observable<UserRegistration>

. To correct this issue, please update your method return type to:

register(email: string, password: string, firstName: string, lastName: string,location: string): Observable<boolean>

It seems that there may be a logic error in your implementation since the method will always return true.

Answer 2

After reviewing your code, it appears that you are currently returning a boolean value as true, even though the definition specifies that it should return

Observable<UserRegistration>

. To correct this issue, please update your method return type to:

register(email: string, password: string, firstName: string, lastName: string,location: string): Observable<boolean>

It seems that there may be a logic error in your implementation since the method will always return true.

Answer 3

Answer №2

The mistake is quite apparent. You specified to Typescript that you expect the method to return an observation of UserRegistration while in your code, you mapped and returned the result as Boolean on this particular line:

.map(res => true)

Based on your implementation - if there is no error thrown from the http request, then map the result to "true" and return it.

To rectify this issue, simply change the type in the first line from

Observable<UserRegistration>

to Observable<boolean>

Answer 4

The mistake is quite apparent. You specified to Typescript that you expect the method to return an observation of UserRegistration while in your code, you mapped and returned the result as Boolean on this particular line:

.map(res => true)

Based on your implementation - if there is no error thrown from the http request, then map the result to "true" and return it.

To rectify this issue, simply change the type in the first line from

Observable<UserRegistration>

to Observable<boolean>

Answer 5

Answer №3

Greetings from stackoverflow!

It appears that your map statement is returning true:

return this.http.post(this.baseUrl + "/accounts", body, options)
  .map(res => true)
  .catch(this.handleError);

If you intend to return the observable instead, there's no need to use map.

May I ask which versions of Angular and RxJS you are currently utilizing?

For those on the latest version of Angular (v7), the code should be written as follows:

return this.http.post(this.baseUrl + "/accounts", body, options).pipe(
  catchError(this.handleError)
);

Answer 6

Greetings from stackoverflow!

It appears that your map statement is returning true:

return this.http.post(this.baseUrl + "/accounts", body, options)
  .map(res => true)
  .catch(this.handleError);

If you intend to return the observable instead, there's no need to use map.

May I ask which versions of Angular and RxJS you are currently utilizing?

For those on the latest version of Angular (v7), the code should be written as follows:

return this.http.post(this.baseUrl + "/accounts", body, options).pipe(
  catchError(this.handleError)
);

Answer 7

Answer №4

If you have a UserRegistration object that you need to return, the code snippet below can be used. I made some slight modifications

register(email: string, password: string, firstName: string, lastName: string, location: string): Observable<UserRegistration> {
    let body = JSON.stringify({ email, password, firstName, lastName, location });
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });

    return this.http.post(this.baseUrl + "/accounts", body, options)  
      .catch(this.handleError);
  }

Answer 8

If you have a UserRegistration object that you need to return, the code snippet below can be used. I made some slight modifications

register(email: string, password: string, firstName: string, lastName: string, location: string): Observable<UserRegistration> {
    let body = JSON.stringify({ email, password, firstName, lastName, location });
    let headers = new Headers({ 'Content-Type': 'application/json' });
    let options = new RequestOptions({ headers: headers });

    return this.http.post(this.baseUrl + "/accounts", body, options)  
      .catch(this.handleError);
  }

Answer 9

Answer №5

Looks like your return type is currently set to

Observable<UserRegistration>

, but you're returning a boolean instead. You have two options here: either update the return type to Observable<boolean>, or make sure you are returning an object of type

Observable<UserRegisteration>

.

Glad to have you here on Stackoverflow!👋

Answer 10

Looks like your return type is currently set to

Observable<UserRegistration>

, but you're returning a boolean instead. You have two options here: either update the return type to Observable<boolean>, or make sure you are returning an object of type

Observable<UserRegisteration>

.

Glad to have you here on Stackoverflow!👋

The type 'Observable<boolean>' cannot be assigned to type 'Observable<UserRegistration>'

Answer №1

Answer №2

Answer №3

Answer №4

Answer №5

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