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I'm trying to pass a single variable from one component to another. It is an array and is declared as follows.

@Component({
  selector: 'component1',
  templateUrl: './component1.component.html',
  styleUrls: ['./component1.css'],
})
export class Component1 implements OnInit{
  ......
  columnVars = Object.keys(this.settings.columns);
  ......
}

So I set up my second component to extend my first and reference the variable like so and it works just as expected.

<table>
  <thead>
    <tr>
      <th>Column</th>
      <th>Description</th>
    </tr>
  </thead>
    <tbody *ngFor="let col of columnVars">
      <tr>
        <td>{{settings.columns[col]['title']}}</td>
        <td>{{settings.columns[col]['description']}}</td>
      </tr>
    </tbody>
</table>

The second component looks like this and this is where the problem comes in.

@Component({
  selector: 'component2',
  templateUrl: './component2.html',
  styleUrls: ['./component2.css']
})

export class Component2 extends Component1 implements OnInit {

  buttonObjList = {
    headendsButton: {
      title: 'Back to headends',
      route: '/headends',
    }
  };
}

I get the error 

ERROR in /home/grady/honeybadger-mat/src/app/column-info/column-info.component.ts (9,14): Class 'ColumnInfoComponent' incorrectly extends base class 'IngestViewComponent'.

  Types of property 'buttonObjList' are incompatible.
    Type '{ headendsButton: { title: string; route: string; }; }' is not assignable to type '{ columnInfo: { title: string; route: string; }; }'.
      Property 'columnInfo' is missing in type '{ headendsButton: { title: string; route: string; }; }'.

Which makes sense. So now my question is is there a way to pass a variable to another component without inheritance or a way to override specific inherited variables like buttonObjList? Thank you in advance.

Edit: To clarify I do not need to display this second component in my first component. So it seems the @input directive won't benefit me in this case. Correct me if I'm wrong.

user3736114
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  • It's not clear what you are trying to accomplish. How are the 2 components related? Passing information between 2 components is highly dependent on how they are related. That context is not clear from your question. – amal Oct 09 '17 at 23:18
  • They're not really related. They're just different views. One component shows a table. The other component explains what each column means on the table. – user3736114 Oct 09 '17 at 23:23
  • a little confused, so if one component explains what each columns mean on a table represented by the other component, they should be related in some way right? I mean is this column-component appearing within the template definition of the table-component? – amal Oct 09 '17 at 23:31
  • The column component does not show up in the table component. It's a separate view. What kind of relationship can I use is it's not a child component? I'm thinking about making the column component a modal to simplify this but I would still like to know the answer for the future. – user3736114 Oct 09 '17 at 23:44

1 Answers1

1
you can Achieve following way.

First Method:-(Global Variable Set and Get Example)

Step 1:
Declare a Global Variable in app.component.ts

export class AppComponent  {
    public static dataNavigate;
}
Step2:
import a App Component in Your Value Set Component(first.component.ts)

import {AppComponent} from '../app.component.ts';

AppComponent.columnVars = Object.keys(this.settings.columns);
//Your Value Set here

Now you can access every component in your app.
second.component.ts
import {AppComponent} from './app.component';

constructor(){
  console.log(AppComponent.columnVars);
}



Second Method:-(Common Service)

Step 1:
      Create a Service
dataService.ts
---------
import { Injectable } from '@angular/core';

@Injectable()
export class DataService {
constructor(){

}
public columnVars:any;
}

Step 2:
Import app.module.ts file

import {DataService} from './data.service';

providers:[DataService]

Step 3:
Set the Value to the Common Service Variable

first.component.ts
import {DataService} from './data.service';

constructor(dataService:DataService){
  this.dataService.columnVars="whatever maybe json or object etc..";
}

Step 4:
Access that you can do same way step3
second.component.ts
import {DataService} from './data.service';

constructor(dataService:DataService){
  console.log(this.dataService.columnVars);
}

other way is also possible you can set your variable some session or localstorage and use it for further visit Local storage in Angular 2

I believe its useful.

Karnan Muthukumar
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