Angular2 Input() output()

Input()

Parent Component : Initialize users lists.

@Component({
  selector: 'parent-component',
  template: '<div>
                <child-component [users]="users"></child-component>
             </div>'
})
export class ParentComponent implements OnInit{
  let users : List<User> = null;
  
  ngOnInit() {
    users.push(new User('A', 'A', 'A@gmail.com');
    users.push(new User('B', 'B', 'B@gmail.com'); 
    users.push(new User('C', 'C', 'C@gmail.com');  
  }      
}

Child component get user from parent component with Input()

@Component({
selector: 'child-component',
  template: '<div>
                  <table *ngIf="users !== null">
                    <thead>
                         <th>Name</th>
                         <th>FName</th>
                         <th>Email</th>   
                    </thead>
                    <tbody>
                        <tr *ngFor="let user of users">
                            <td>{{user.name}}</td>
                            <td>{{user.fname}}</td>
                            <td>{{user.email}}</td>
                        </tr>
                    </tbody>
                  </table>
                
             </div>',
})
export class ChildComponent {
  @Input() users : List<User> = null;
}


export class User {
  name : string;
  fname : string;
  email : string;

  constructor(_name : string, _fname : string, _email : string){
     this.name = _name;
     this.fname = _fname;
     this.email = _email;
  }
}

Simple example of Input Properties

Parent element html

<child-component [isSelected]="inputPropValue"></child-component>

Parent element ts

export class AppComponent {
     inputPropValue: true
}

Child component ts:

export class ChildComponent {
    @Input() inputPropValue = false;
}

Child component html:

<div [class.simpleCssClass]="inputPropValue"></div>

This code will send the inputPropValue from the parent component to the child and it will have the value we have set in the parent component when it arrives there - false in our case. We can then use that value in the child component to, for example add a class to an element.