Get selected value from the drop down list with Angular

Question

<tr (click)="onRowClick(myDropDownList.value)">
<td>
<select #myDropDownList (click)="$event.stopPropagation()" (change)="onChange($event.target.value)">
    <option *ngFor="let n of numbers" [value]="n">{{n}}</option>
</select>
</td>
</tr>

I was trying to get selected value from the drop down list and assign it to the onRowClick function. But myDropDownList always appears to be undefined for some reason. I was wondering what might go wrong here.

Answer 1

Make use of Forms or ngModel for this case . Using Forms

Template

<form [formGroup]="test">
        <div class="col-sm-6 form-group">
            <label>Industry</label>
            <tr (click)="onRowClick(myDropDownList.value)"> Click
                <td>
                    <select #myDropDownList class="form-control select" formControlName="Industry">
          <option [selected] = "true == true" [ngValue] = "0"> Please Select</option>
          <option *ngFor="let industry of industries"  [ngValue]="industry.id">{{industry.name}} </option>  
    </select>
                </td>
            </tr>
        </div>
    </form>

Component

export class AppComponent implements OnInit { 
  name = 'Angular 5';
  test:FormGroup;
  industries = [{id:1,name:"rahul"},{id:2,name:"jazz"}];

  ngOnInit(){
     this.test = new FormGroup({
      Industry:new FormControl('')
    });

    this.test.get('Industry').valueChanges.
    subscribe(data =>
      console.log(this.industries.filter(d =>  {return d.id == data}))
    );

  }

  onRowClick(value){
    console.log("called");
    alert(value);
  }

}

Working Example

Answer 2

I actually ended up with using ElementRef as the solution, which in my opinion is probably simpler and more straightforward.

@ViewChild('myDropDownList') myDropDownList: ElementRef;

onRowClick(){
    const selectedValue = this.myDropDownList.nativeElement.value;
    //...
}

Using forms was just a bit overkill in my case. But thanks for putting it out as another possible alternative.

Answer 3

Change your drop down HTML like the below

<select [(ngModel)]="selectedNumber" (ngModelChange)="onRowClick()" >
    <option *ngFor="let n of numbers" value={{n}}>{{n}}</option>
</select>

In TS file you can declare selectedNumber to pass default value or you can use inside onRowClick function to get the selected number

selectedNumber : number = 1;


onRowClick(){
console.log(this.selectedNumber)
}

You can find the working version here

Answer 4

You can pass an event and retrieve event.target.value

<select id="accounts">
      <option *ngFor="let account of accounts" [value]="account.value" (click)="selectAccount($event)">{{account.name}}</option>
    </select>

selectAccount(event){
    console.log(event.target.value)
  }