Binding select element to object in Angular

user_372296 0
Viewed 644076

I'd like to bind a select element to a list of objects -- which is easy enough:

@Component({
   selector: 'myApp',
   template: 
      `<h1>My Application</h1>
       <select [(ngModel)]="selectedValue">
          <option *ngFor="#c of countries" value="c.id">{{c.name}}</option>
       </select>`
    })
export class AppComponent{
   countries = [
      {id: 1, name: "United States"},
      {id: 2, name: "Australia"}
      {id: 3, name: "Canada"},
      {id: 4, name: "Brazil"},
      {id: 5, name: "England"}
   ];
   selectedValue = null;
}

In this case, it appears that selectedValue would be a number -- the id of the selected item.

However, I'd actually like to bind to the country object itself so that selectedValue is the object rather than just the id. I tried changing the value of the option like so:

<option *ngFor="#c of countries" value="c">{{c.name}}</option>

but this does not seem to work. It seems to place an object in my selectedValue -- but not the object that I'm expecting. You can see this in my Plunker example.

I also tried binding to the change event so that I could set the object myself based on the selected id; however, it appears that the change event fires before the bound ngModel is updated -- meaning I don't have access to the newly selected value at that point.

Is there a clean way to bind a select element to an object with Angular 2?

angular html
16 Answers

The key is to use a two way binding in the select via [(ngModel)] and use [ngValue] in each option.

You can even have a default null option and it works with Angular 12.

<select name="typeFather" [(ngModel)]="selectedType">
  <option [ngValue]="null">Select a type</option>
  <option *ngFor="let type of types" [ngValue]="type">{{type.title}}</option>
</select>

That approach is always going to work, however if you have a dynamic list, make sure you load it before the model.

user_124379720

Create another getter for selected item

<form [formGroup]="countryForm">
  <select formControlName="country">
    <option *ngFor="let c of countries" [value]="c.id">{{c.name}}</option>
  </select>

  <p>Selected Country: {{selectedCountry?.name}}</p>
</form>

In ts : 

get selectedCountry(){
  let countryId = this.countryForm.controls.country.value;
  let selected = this.countries.find(c=> c.id == countryId);
  return selected;
}
user_34126960

In app.component.html:

<select type="number" [(ngModel)]="selectedLevel">
  <option *ngFor="let level of levels" [ngValue]="level">{{level.name}}</option>
</select>

And app.component.ts:

import { Component } from '@angular/core';

@Component({
  selector: 'my-app',
  templateUrl: './app.component.html',
  styleUrls: [ './app.component.css' ]
})
export class AppComponent  {
  levelNum:number;
  levels:Array<Object> = [
      {num: 0, name: "AA"},
      {num: 1, name: "BB"}
  ];

  toNumber(){
    this.levelNum = +this.levelNum;
    console.log(this.levelNum);
  }

  selectedLevel = this.levels[0];

  selectedLevelCustomCompare = {num: 1, name: "BB"}

  compareFn(a, b) {
    console.log(a, b, a && b && a.num == b.num);
    return a && b && a.num == b.num;
  }
}
user_101168120

Also, if nothing else from given solutions doesn't work, check if you imported "FormsModule" inside of "AppModule", that was a key for me.

user_92169320

use this way also..

<h1>My Application</h1>
<select [(ngModel)]="selectedValue">
     <option *ngFor="let c of countries" value="{{c.id}}">{{c.name}}</option>
 </select>
user_61561260

Attention Angular 2+ users: for some reason, [value] does not work on elements. use [ngModel] instead.

<select [ngModel]="selectedCountry">
    <option *ngFor="let country of countries" [value]="country">{{country.name}}</option>
</select>
user_16597920

Tested on Angular 11. I need an extra object 'typeSelected'. Pay attention I'm not using [(ngValue)] as other answers do:

<mat-select formControlName="type" [(value)]="typeSelected" 
            [compareWith]="typeComparation">
  <mat-option *ngFor="let myType of allSurveysTypes" [value]="myType">
    {{myType.title}}
  </mat-option>
</mat-select>

//Declaration.
typeSelected: SurveyType;
...

//Assigning variable 'type' of object 'survey' to 'typeSelected'.
this.typeSelected = survey?.type;
...

    
//Function to compare SurveyType objects.
typeComparation = ( option, value ) =>  {
  if (option && value) {
    return option.id === value.id;
  }
}
user_37423790

This code is very simple:

<select class="form-control" id="marasemaat" [(ngModel)]="fullNamePresentor" 
        [formControl]="stateControl" (change)="onSelect($event.target.value)">
  <option *ngFor="let char of programInfo1;let i = index;" 
          onclick="currentSlide(9,false)" 
          value={{char.id}}>{{char.title + " "}}  ----> {{char.name + " "+ char.family }} ---- > {{(char.time.split('T', 2)[1]).split(':',2)}}</option>
</select>
user_101168120
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