import { PipeTransform } from '@angular/core';
import { SelectItem } from './select-item.model';
/**
 * 将枚举转换为 SelectItem
 */
export declare function transformToSelectItem(value: any, optionalItem?: boolean | string): SelectItem[];
/**
 * Keyvalue select dropdown, use with enum, or object
 * @example
 *  <select [(ngModel)]="myDirectionValue">
 *      <option value=""></option>
 *      <option *ngFor="let a of myDirection | appSelectItem" [value]="a.value">{{a.label}}</option>
 *  </select>
 *
 *
 *      public myDirection       = NumberDirection;             // type of enum
 *      public myDirectionValue =  NumberDirection.Down;        // enum value
 *
 *
 *      export enum NumberDirection {
 *           Up    = 1,
 *           Down  = 2,
 *           Left  = 4,
 *           Right = 'abc'.length
 *      }
 *
 *      export enum StringDirection {
 *          Up    = 'aUp',
 *          Down  = 'aDown',
 *          Left  = 'aLeft',
 *          Right = 'aRight'
 *      }
 */
export declare class SelectItemPipe implements PipeTransform {
    /**
     * transform
     *
     * @param value type of enum
     * @param optionalItem 添加默认的空项
     */
    transform(value: any, optionalItem?: boolean | string): SelectItem[];
}
export declare class SelectItemPipeModule {
}