Angular 2 Issue: @Input() Directive Not Recognized - Unresolved Reference Error

I am a beginner trying to grasp Angular2 concepts from ng-book 2(v49). Below is the code snippet from article.componenets.ts file:

import { Component, OnInit } from '@angular/core';
import { Article } from './article.model';

@Component({
  selector: 'app-article',
  templateUrl: './article.component.html',
 styleUrls: ['./article.component.css'],
 host: {
 class: 'row'
 }
})
export class ArticleComponent implements OnInit {
  @Input() article: Article;



  voteUp(): boolean {
    this.article.voteUp();
    return false;
  }

  voteDown(): boolean {
    this.article.voteDown();
    return false;
  }

  ngOnInit() {
  }

}

Encountered an error while using angular-cli:

ERROR in C:/Users/saad/Desktop/books/Angular JS2/angular2Reddit/src/app/article/article.component.ts (13,4): Cannot find name 'Input'.)
webpack: Failed to compile.

https://i.sstatic.net/Q2gdI.png

Answer №1

Don't forget to include the Import directive for Input in your code. Update the first line as follows:

import { Component, OnInit, Input } from '@angular/core';

Always remember to assign a value to @Input parameters to avoid encountering an Unhandled promise error within your application.

You can define this inside either your ngOnInit method or your constructor.

ngOnInit() {
   this.article={
         id: 0
         .....
   };
}

or

constructor(....) {
   this.article={
         id: 0,
         .....
   };
}

Answer №2

To utilize Input within your code, you must import it:

import { Component, OnInit, Input } from '@angular/core';

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