How to assign a value to variable inside subscription?

Question

I have Ionic 4 angular project, I need to assign value while reading inside subscribe. However I could not do that. I know there are several Questions and Answers related to mine. However none of them is working for me. Here is the my code and I tried so far. Any comments, any help is appriciated. Thank you very much.`

Service.ts

  public loggedChecker: any;
  private lofff = new Subject<any>();

    postLoginToServer (password, email) {
    var headers = new Headers();
    headers.append("Accept", 'application/json');
    headers.append('Content-Type', 'application/json' );
    let postData =  {
     password: password,
     mail: email
 }
 console.log("8888888888888888888888888888888");

    this.http.post("http://localhost:8080/api/login", postData, { observe: 'response'} )
      .pipe(map(data =>  this.loggedChecker =(data.body)));

      console.log(this.loggedChecker,"0330303333333333"); //undefined

      return this.loggedChecker+"";
}

And here is the another I try

  postLoginToServer (password, email) {
    var headers = new Headers();
    headers.append("Accept", 'application/json');
    headers.append('Content-Type', 'application/json' );
    let postData =  {
     password: password,
     mail: email
 }
    this.http.post("http://localhost:8080/api/login", postData,{observe: 'response'})
      .subscribe(data => {
         
        this.loggedChecker =(data.body);
        
        this.textToDisplay = (data.body);
        this.lofff.next(data);
       }, error => {
        console.log(error);
      });

    console.log(this.lofff,"logged checker");
    
    return this.loggedChecker+"";
    }

Here is the page.ts

Page.ts

 logForm(){    
   
   console.log(this.fineService.postLoginToServer(this.passwordUser, this.email));
}
    

Both of them are not working. Thank you.

Answer 1

From what I understand you are trying to assign a class property named loggedChecker. This is what you should do:

  postLoginToServer (password, email) {
    var headers = new Headers();
    headers.append("Accept", 'application/json');
    headers.append('Content-Type', 'application/json' );
    let postData =  {
     password: password,
     mail: email
    }
    this.http.post("http://localhost:8080/api/login", postData,{observe: 'response'})
      .pipe(tap(data => {
        this.loggedChecker =(data.body);
        this.textToDisplay = (data.body);
        this.lofff.next(data);
       }, error => {
        console.log(error);
      }));
    }

tap(import from rxjs) operator will not change the data but can be used to do things like what you're trying to do.

UPDATE: You should change your logForm function.

 logForm(){    
   console.log(this.fineService.postLoginToServer(this.passwordUser, this.email));
}

should be

     logForm(){    
       this.fineService.postLoginToServer(this.passwordUser, this.email).subscribe(data => {
        console.log(data);
       })
    }

because the HTTP request will return an observable and you will get its value when you subscribe to it.