订阅不是Angular函数

Question

I am trying to return the value while subscribing and I am getting the value also but getting the error also

** Inside Service **

getColumnValueg(): Observable<any>
{  console.log("service",this.colValueg);
   return (this.colValueg);
}

** FormComponent **

ngOnInit()
{
  // perform the task of sending and receiving value.
  console.log("inint form-lib component",this.UserFormArray);

  this.UserFormArray = this.service.getFormDetails();

  this.service.getColumnValueg().subscribe(data => this.g1 = data);
  this.service.getColumnValueg().subscribe(data => this.lg1 = data);
  this.service.getColumnValueg().subscribe(data => this.md1 = data);

  console.log('userformarray',this.UserFormArray);
  console.log(this.g1,this.lg1,this.md1);
}

but data is not getting called after that I called these service method from a button click event then it showed the value. I am getting the error to subscribe is not a function. I tried using of, from it's not working. I am trying to fetch value on page load but i am not able to fetch data on page load

Edited
The problem is solved but the next problem raised is that I am not able to fetch the value on nginit

Answer 1

Change your method which returns the Observable

getColumnValueg(): Observable<any>
{  console.log("service",this.colValueg);
   return Observable.of(this.colValueg);
}

OR

getColumnValueg(): Observable<any>
{  console.log("service",this.colValueg);
   return of(this.colValueg);
}

Change in ngOnInit

   ngOnInit()
    {
      // perform the task of sending and receiving value.
      console.log("inint form-lib component",this.UserFormArray);

      this.UserFormArray = this.service.getFormDetails();

      this.service.getColumnValueg().subscribe(data => {
          console.log(" ColumnValue data " , data);
      });

      console.log('userformarray',this.UserFormArray);
      console.log(this.g1,this.lg1,this.md1);
    }

Demo link is here - https://stackblitz.com/edit/angular-srabjg

Answer 2

Looks like this.colValueg is not an Observable. You'll have to convert it into one. You can use of to do that:

If you're using Rxjs6:

import { of } from 'rxjs';
...
colValueg = 'Some Value';
...
getColumnValueg(): Observable < any > {
  console.log("service", this.colValueg);
  return of(this.colValueg);
}

If you're using Rxjs5:

import { Observable } from "rxjs/Observable";
...
colValueg = 'Some Value';
...
getColumnValueg(): Observable < any > {
  console.log("service", this.colValueg);
  return Observable.of(this.colValueg);
}