Ways to access the JSON data beyond the subscribe function

After obtaining JSON data from the backend, my goal is to store it in a variable for populating a table. Below is the code snippet I am working with:

@Component({
  selector: 'app-kontakte',
  templateUrl: './kontakte.component.html',
  styleUrls: ['./kontakte.component.scss'],
})
export class KontakteComponent implements OnInit {

  textArea: string;
  minlength: number;
  maxlength = 100000;

  constructor(private kontakteService: KontakteService) {
    this.textArea = '';
    this.minlength = 1;
  }
  
  ngOnInit(): void {
    this.reload();
  }

  public reload():void {
    this.kontakteService.getTpoContacts().subscribe((res) => {
      this.textArea = JSON.stringify(res);
      console.log(this.textArea); // <-- Data output is visible here
    });
    console.log(this.textArea) // <- Empty string appears here 
  }
}


My intention was to store the JSON data in the textArea variable and then utilize it to populate a table. The retrieved data inside the subscription functions properly, but outside of it, the this.textArea remains empty.

If you have any suggestions on how I can resolve this issue, please share as I am relatively new to Angular.

Answer №1

The results are already being saved to a variable in your code snippet:

this.resultData = JSON.stringify(response);

Once the asynchronous function is finished, the variable resultData will contain the necessary information. The issue arises when you try to access it before the data has returned from the server:

public fetchData(): void {

    this.dataService.fetchData().subscribe((response) => {
        // This block of code will only execute once the data retrieval is complete.
        this.resultData = JSON.stringify(response);
        console.log(this.resultData); // <-- At this point, the data is logged correctly
    });

    // This line will run immediately because the service call above doesn't pause the execution
    console.log(this.resultData) // <- At this stage, an empty string is printed 
}

Avoid accessing the variable prematurely.

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