Mapping API response data using Angular's HTTP call

Question

Mapping API response data using Angular's HTTP call

I want to retrieve my travel details, which are returned from an API in Angular.

From the backend, I receive:

{
  "trips": [
    {
      "id": 0,
      "name": "string",
      "startDate": "2019-06-30T06:05:48.006Z",
      "endDate": "2019-06-30T06:05:48.006Z",
      "description": "string",
      "roomSharing": true,
      "countries": [
        {
          "id": 0,
          "name": "string",
          "code": "string"
        }
      ],
      "languages": [
        {
          "id": 0,
          "name": "string",
          "code": "string"
        }
      ]
    }
  ]
}

This is all good, but I'm facing a challenge on the client side. Here's my code for fetching trips:

getTrips(): Observable<Trip[]> {
    return this.http.get<Trip[]>(this.apiUrl + '/Trip/Get')
      .pipe(
        tap(_ => console.log('fetched trips')),
        retry(1),
        catchError(this.handleError),
        map(data => {
          return data;
        })
      );
}

In my component, I have:

loadTrips() {
    return this.rest.getTrips()
    .subscribe((data) => {
      this.trips = data;
      console.log(this.trips);
    }
    , err => console.log(err));
}

I want to display trips in a template like:

<div class="card mb-3 trip" *ngFor="let trip of trips">

But currently, I need to use:

<div class="card mb-3 trip" *ngFor="let trip of trips.trips">

Hence, my question is how can I transform my response to get an array of Trip instead of an array of Trips arrays?

javascript angular typescript observable

Answer 1

Answer №1

It seems like this code snippet should do the trick:

  interface TripsResponse {
    trips: Trips[],
  }

  getTrips(): Observable<Trip[]> {
    // Make sure to replace Trip[] with your response interface
    //return this.http.get<Trip[]>(this.apiUrl + '/Trip/Get')
    return this.http.get<TripsResponse>(this.apiUrl + '/Trip/Get')
      .pipe(
        tap(_ => console.log('fetched trips')),
        retry(1),
        catchError(this.handleError),
        map(data => {
          return data.trips; // Adjust as needed here
        })
      );
  }

Answer 2

It seems like this code snippet should do the trick:

  interface TripsResponse {
    trips: Trips[],
  }

  getTrips(): Observable<Trip[]> {
    // Make sure to replace Trip[] with your response interface
    //return this.http.get<Trip[]>(this.apiUrl + '/Trip/Get')
    return this.http.get<TripsResponse>(this.apiUrl + '/Trip/Get')
      .pipe(
        tap(_ => console.log('fetched trips')),
        retry(1),
        catchError(this.handleError),
        map(data => {
          return data.trips; // Adjust as needed here
        })
      );
  }

Answer 3

Answer №2

Revise your return statement:

return this.http.get('/Tour/Retrieve')
  .pipe(
    tap(_ => console.log('retrieved tours')),
    retry(1),
    catchError(this.handleError),
    map((data: ToursResponse) => {   // modification made here; ensure data is of type ToursResponse 
      return data.tours; 
    })
  );

where ToursResponse is

interface ToursResponse {
   tours: Tours[],
   ... // additional fields for potential future use
}

Answer 4

Revise your return statement:

return this.http.get('/Tour/Retrieve')
  .pipe(
    tap(_ => console.log('retrieved tours')),
    retry(1),
    catchError(this.handleError),
    map((data: ToursResponse) => {   // modification made here; ensure data is of type ToursResponse 
      return data.tours; 
    })
  );

where ToursResponse is

interface ToursResponse {
   tours: Tours[],
   ... // additional fields for potential future use
}

Answer 5

Answer №3

Keep it simple by using direct assignment instead of using .map:

 loadTrips() {
    return this.rest.getTrips()
    .subscribe((data) => {
      this.trips = data.trips;
    }
    , err => console.log(err));
  }

Make sure to correct the model Trip[] which should be:

export interface ITripsResponse {
    trips: Trip[],
  }

Update the code line to:

return this.http.get<ITripsResponse>(this.apiUrl + '/Trip/Get')

If not, adjust .map as follows:

    map((data) => {   
      return data.trips; 
    })

This way, Observable<Trip[]> would be an appropriate return type

Answer 6

Keep it simple by using direct assignment instead of using .map:

 loadTrips() {
    return this.rest.getTrips()
    .subscribe((data) => {
      this.trips = data.trips;
    }
    , err => console.log(err));
  }

Make sure to correct the model Trip[] which should be:

export interface ITripsResponse {
    trips: Trip[],
  }

Update the code line to:

return this.http.get<ITripsResponse>(this.apiUrl + '/Trip/Get')

If not, adjust .map as follows:

    map((data) => {   
      return data.trips; 
    })

This way, Observable<Trip[]> would be an appropriate return type

Mapping API response data using Angular's HTTP call

Answer №1

Answer №2

Answer №3

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