Select based on enum in Angular2

update2 simplified by creating an array

@Pipe({name: 'enumToArray'})
export class EnumToArrayPipe implements PipeTransform {
  transform(value) : Object {
    return Object.keys(value).filter(e => !isNaN(+e)).map(o => { return {index: +o, name: value[o]}});
  }
}

@Component({
  ...
  imports: [EnumsToArrayPipe],
  template: `<div *ngFor="let item of roles | enumToArray">{{item.index}}: {{item.name}}</div>`
})
class MyComponent {
  roles = Role;
}

update

instead of pipes: [KeysPipe]

use

@NgModule({
  declarations: [KeysPipe],
  exports: [KeysPipe],
}
export class SharedModule{}
@NgModule({
  ...
  imports: [SharedModule],
})

original

Using the keys pipe from https://stackoverflow.com/a/35536052/217408

I had to modify the pipe a bit to make it work properly with enums (see also How to get names of enum entries?)

@Pipe({name: 'keys'})
export class KeysPipe implements PipeTransform {
  transform(value, args:string[]) : any {
    let keys = [];
    for (var enumMember in value) {
      if (!isNaN(parseInt(enumMember, 10))) {
        keys.push({key: enumMember, value: value[enumMember]});
        // Uncomment if you want log
        // console.log("enum member: ", value[enumMember]);
      } 
    }
    return keys;
  }
}

@Component({ ...
  pipes: [KeysPipe],
  template: `
  <select>
     <option *ngFor="let item of countries | keys" [value]="item.key">{{item.value}}</option>
  </select>
`
})
class MyComponent {
  countries = CountryCodeEnum;
}

Plunker

See also How to iterate object keys using *ngFor?


One more solution if you don't want to create a new pipe. You could also extract keys into helper property and use it:

@Component({
  selector: 'my-app',
  providers: [],
  template: `
    <div>
      <select>
        <option *ngFor="let key of keys" [value]="key" [label]="countries[key]"></option>
      </select>
    </div>
  `,
  directives: []
})
export class App {

  countries = CountryCodeEnum

  constructor() {
    this.keys = Object.keys(this.countries).filter(k => !isNaN(Number(k)));
  }
}

Demo: http://plnkr.co/edit/CMFt6Zl7lLYgnHoKKa4E?p=preview

Edit:

if you need the options as numbers instead of strings:

  • replace [value] with [ngValue]
  • add .map(Number) after .filter(...)