How to export a variable withinin a class and function to another component in Angular?

Question

I have a component named flow.component.ts like this:

var rsi_result: number[];

@Component({
  selector: 'flow-home',
  templateUrl: './flow.component.html',
  styleUrls: ['./flow.component.scss'],
  host: {
    '[@flyInOut]': 'true',
    'style': 'display: block;'
  },
  animations: [
    flyInOut(),
    expand()
  ]
})
export class FlowComponent implements AfterViewInit {

  setRsi(selectedValue){
    console.log('The RSI period is:' , selectedValue);
    periodd = selectedValue;
    this.label2 = ' نام اندیکاتور:  RSI';
    this.label3 = ' دوره زمانی: ' + periodd + 'روزه';
    rsi_result = rsi({period: periodd, values: pricess});
    console.log('The RSI result is:' ,  rsi_result);
  }

}

export const RSI_RESULT = rsi_result;

The code works well and I can see the result of this line of code in my console console.log('The RSI result is:' , rsi_result); but it seems the export line out of the class doesn't work and I can't use RSI_RESULT in other components and get undefined RSI_RESULT error message! Also when I write rsi_result or RSI_RESULT in console I get the same undefined error!

How is it possible when this line of code console.log('The RSI result is:' , rsi_result); works well and I can see the rsi_result in the console but when I type it by hand I get undefined error message?

EDITL

I tried to create a service named ngx.service with this content:

import { Injectable } from '@angular/core';

var RSI_RESULT: number[];
var MACD_RESULT: number[];

@Injectable({
  providedIn: 'root'
})
export class NgxService {

getRsiResult(){ 

  return (RSI_RESULT);
}  

getMacdResult(){ 
  return (MACD_RESULT);

}

  constructor() { }

}

Then edited the above code to :

export class FlowComponent implements AfterViewInit {

  macd_result: number[];
  rsi_result: number[];
  constructor(private dialog: MatDialog, private ngxService:NgxService) {
  }
  setRsi(selectedValue){
    console.log('The RSI period is:' , selectedValue);
    periodd = selectedValue;
    this.label2 = ' نام اندیکاتور:  RSI';
    this.label3 = ' دوره زمانی: ' + periodd + 'روزه';
    this.rsi_result = rsi({period: periodd, values: pricess});
    console.log('The RSI result is:' ,  this.rsi_result);
  }

}

But when I want to use rsi_result in the following component named ngx-charts I get the same error as before:

import { Component, OnInit } from '@angular/core';
import {MatDialog, MatDialogRef} from '@angular/material';
import { NewsComponent } from '../news/news.component';
import {NgxService} from '../services/ngx.service';
import { Mellat , Khodro, Shepna} from '../shared/stock_inf';


@Component({
  selector: 'app-ngx-charts',
  templateUrl: './ngx-charts.component.html',
  styleUrls: ['./ngx-charts.component.scss']
})



export class NgxChartsComponent implements OnInit {

  rsi_result: number[];
  macd_result: number[];

  constructor(public dialogRef: MatDialogRef<NgxChartsComponent> ,
     private ngxService: NgxService) { }

     ngOnInit() {
      this.rsi_result = this.ngxService.getRsiResult(); //.subscribe(RSI_RESULT => this.rsi_result = RSI_RESULT);
      this.macd_result = this.ngxService.getMacdResult(); //.subscribe(MACD_RESULT => this.macd_result = MACD_RESULT);

      console.log(this.rsi_result); 
    }

  // data goes here
public single = [
  {
    "name": " درصد سود",
    "value": 69
  },
  {
    "name": " درصد زیان",
    "value": 31
  },

];


 newArray = Mellat.map((e, i) => ({
  "name": (i + 1).toString(),
  "value": e,
}));

newArray2 = this.rsi_result.map((e, i) => ({
  "name": (i + 1).toString(),
  "value": e,
}));


public multi = [
  {
    "name": "Mellat",
    "series": this.newArray
  },

  {
    "name": "RSI",
    "series": this.newArray2
  }
];

//{name: (i + 1).toString(), value: e.toString()}



  view: any[];

  // options for the chart
  showXAxis = true;
  showYAxis = true;
  gradient = false;
  showLegend = true;
  showXAxisLabel = true;
  xAxisLabel = 'زمان';
  showYAxisLabel = true;
  yAxisLabel = 'قیمت';
  timeline = true;

  colorScheme = {
    domain: ['#5AA454', '#A10A28', '#C7B42C', '#AAAAAA']
  };

  // line, area
  autoScale = true;

  //pie
  showLabels = true;
  explodeSlices = false;
  doughnut = false;


}

EDIT2:

I reviewd my code again and noticed that I must delete var RSI_RESULT: number[]; and MACD_RESULT: number[]; from my app and also replace this.rsi_result lines to this.ngxService.RSI_RESULT when my ngx.service.ts file looks like this:

import { Injectable } from '@angular/core';
import {Observable, of} from 'rxjs';



@Injectable({
  providedIn: 'root'
})
export class NgxService {

RSI_RESULT: number[];
MACD_RESULT: number[];

getRsiResult(){ //: Observable<number[]>{

  return (this.RSI_RESULT);
}  

getMacdResult(){ //: Observable<number[]>{
  return (this.MACD_RESULT);

}

  constructor() { }

}

And the program works well by now!

Answer 1

Yo have to put your share info in an service and inject that service into all your components.

export class FlowComponent implements AfterViewInit {

  constructor(private readonly myService: MyService){}

  setRsi(selectedValue){
    console.log('The RSI period is:' , selectedValue);
    periodd = selectedValue;
    this.label2 = ' نام اندیکاتور:  RSI';
    this.label3 = ' دوره زمانی: ' + periodd + 'روزه';
    this.myService.setRsi(rsi({period: periodd, values: pricess}));
    console.log('The RSI result is:' ,  rsi_result);
  }

}




// Other file
export class OtherComponent {

  constructor(private readonly myService: MyService){}

  getRsi(){
     return this.myService.getRsi();
   }

}