How to get ngModel value of input tag into a component in angularjs4?

Question

I am new to angularjs4. I am working on angular-cli.Here I need to get the value of a ngModel value of input tag in my component.How can I get that value entered in input field?By using that value I need to write a filter for displaying searched data on my page.How can I Implement this one in angular4?. Here is my app.component.html and app.component.ts files:

import {
    Component
} from '@angular/core';
import {
    Http,
    Response,
    Headers,
    RequestOptions
} from '@angular/http';
import 'rxjs/add/operator/map';

@Component({
    selector: 'app-root',
    templateUrl: './app.component.html',
    styleUrls: ['./app.component.css']
})
export class AppComponent {
    productsList = '';
    show: boolean;
    hide: boolean;
    listBtn: boolean;
    gridBtn: boolean;
    values = '';

    onKey(event: any) { // without type info
        this.values += event.target.value;
        console.log("value " + this.values);
    }
    listView() {
        this.gridBtn = true;
        this.show = true;
        this.hide = false;
        this.listBtn = false;
    }
    gridView() {
        this.listBtn = true;
        this.gridBtn = false;
        this.show = false;
        this.hide = true;

    }
    constructor(private http: Http) {
        this.show = false;
        this.hide = true;
        this.show = false;
        this.listBtn = true;
        this.gridBtn = false;
        this.getData();
    }
    createAuthorizationHeader(headers: Headers) {
        headers.append('Authorization', 'Basic ' +
            btoa('ck_543700d9f8c08268d75d3efefb302df4fad70a8f:cs_f1514261bbe154d662eb5053880d40518367c901'));
        headers.append("Content-Type", "application/x-www-form-urlencoded");
    }
    getData() {
        console.log('hellooo');
        let headers = new Headers();
        this.createAuthorizationHeader(headers);
        return this.http.get(' https://www.colourssoftware.com/wordpress/wp-json/wc/v2/products', {
            headers: headers
        })
            .subscribe(res => {
                const products = res.json();
                console.log(products);
                this.productsList = products;
                console.log(this.productsList);
            })


    }

}

HTML

<div class="container" align="center">
    <div class="row">
        <div class="col-sm-6 col-sm-offset-3">
            <div class="input-group stylish-input-group">
                <input type="text" class="form-control" placeholder="Let's find your product....." (keyup)="onKey($event)">
                <span class="input-group-addon">
                    <button type="submit">
                        <span class="glyphicon glyphicon-search"></span>
                    </button>
                </span>
            </div>
        </div>
    </div>
    <br>
</div>


<br>
<div *ngIf="show">
    <ul class="list-group">
        <li class="list-group-item" *ngFor="let data of productsList">
            <img src="{{data.images[0].src}}" alt="image" width="auto" height="200px">
            <span>{{data.name}}</span>
            <span>{{data.regular_price}}</span>
        </li>
    </ul>
</div>

Answer 1

1.If you want one way data binding (Component to HTML), use -

<input [ngModel]="variable">

2.If you want two way data binding (Component to HTML and vice versa), use -

<input [(ngModel)]="variable">

3.If you want to work with the data changed in input field in html while working with one way data binding, you have to use (ngModelChange) as below :

<input [ngModel]="variable"(ngModelChange)="function_to_fire_on_model_change($event)">

Answer 2

UPDATE:

If you want to get the input value, but without ngModel (as in your snipet you don't use it), you can get as this:

 <input type="text" #input class="form-control" placeholder="Let's find your product....." (keyup)="onKey($event, input.value)">

onKey(event, newValue){
  console.log(newValue);
  console.log(event.key)
}

---

Usually, the pattern would be:

HTML

<input [(ngModel)]="yourModel" ....> 

or

<input [ngModel]="yourModel" (ngModelChange)="doSomething($event)"....> 

Typescript:

yourModel:any;
....
doSomething(event){
   console.log(event) // input value is logged
}

Here any changes in the input will update the ngModel as it's two-way bound.

• Angular documentation