Storage Ionic 4

Question

I'm a beginner in the Angular world and I'm tempted to insert and retrieve information in ionic storage 4, however, when I try to retrieve it it returns me empty array.

I did the following

export class OcorrenciasPage implements OnInit {

  public ocorrencia: CAD231SolitacaoOcorrencia[] = new Array();
  public url = 'http://localhost:53834/api/';
  constructor(private ocorrenciaService: CAD231SolicitacaoOcorrenciaService, private storage: Storage, private http: HttpClient) {



    this.http.get(this.url + 'CAD231/').subscribe(response => {
      for (let i = 0; i < Object.keys(response).length; i++) {
        this.ocorrencia.push({
          'idSolitacaoOcorrencia': response[i]['IdSolicitacaoOCorrencia'],
          'idProvedor': response[i]['IdProvedor'],
          'idStatusOcorrencia': response[i]['IdStatusOcorrencia'],
          'idTipoSolitacaoOcorrencia': response[i]['IdTipoSolicitacaoOcorrencia'],
          'dataCadastro': response[i]['DataCadastroSolicitacao'],
          'descricaoSolicitacao': response[i]['DescricaoSolicitacao'],
          'idUsuarioCadasro': response[i]['IdUsuarioCadastro'],
          'idCliente': response[i]['IdCliente']
        });
      }
    });
    console.log(this.ocorrencia);
    this.storage.set('ocorrencias',this.ocorrencia)

    storage.get('ocorrencias').then((val) => {
      console.log(val);
    });


  }
  ngOnInit() {

  }
}

the "ocorrencia" property is being filled in correctly,

but the result comes empty, can someone explain why

Aqui está

here is the values of the "occurrence" property and the value returned by the "storage"

score 0 · Accepted Answer · answered Mar 25 '19 at 16:35

subscribe method is using for Observable. Which means it will fire when the object changed. For this example you are getting some data from your back-end service and your program is going to setting storage to localstorage without waiting answer from your back-end. That's why we are using Observable.

To solve this issue you have to set storage after getting your back-end response, so you have to move setting storage method inside of your subscribe. Here is the documentation for Observables

this.http.get(this.url + 'CAD231/').subscribe(response => {
  for (let i = 0; i < Object.keys(response).length; i++) {
    this.ocorrencia.push({
      'idSolitacaoOcorrencia': response[i]['IdSolicitacaoOCorrencia'],
      'idProvedor': response[i]['IdProvedor'],
      'idStatusOcorrencia': response[i]['IdStatusOcorrencia'],
      'idTipoSolitacaoOcorrencia': response[i]['IdTipoSolicitacaoOcorrencia'],
      'dataCadastro': response[i]['DataCadastroSolicitacao'],
      'descricaoSolicitacao': response[i]['DescricaoSolicitacao'],
      'idUsuarioCadasro': response[i]['IdUsuarioCadastro'],
      'idCliente': response[i]['IdCliente']
    });
  }
  console.log(this.ocorrencia);
  this.storage.set('ocorrencias',this.ocorrencia)
  storage.get('ocorrencias').then((val) => {
  console.log(val);
    });
});

Storage Ionic 4

1 Answers1