不支持角度4.x函數調用。考慮與參考替換函數或lambda來導出函數

Question

我試圖提供一種方法來定製服務，通過使用靜態forRoot（），但...

我碰到下面的錯誤 - 即使我已導出menuServiceFactory函數以用作工廠。
我也試着將它作爲const值導出。

ERROR in Error: Error encountered resolving symbol values statically. Calling function 'MenuModule', function calls are not supported. Consider replacing the function or lambda with a reference to an exported function, resolving symbol AppModule in ...

相關的代碼 -

import { NgModule, ModuleWithProviders, SkipSelf, Optional } from '@angular/core'; 
import { CommonModule } from '@angular/common'; 
import { MenuComponent } from './menu.component'; 
import { MenuService } from './menu.service'; 
import { MdMenuModule, MdToolbarModule, MdButtonModule } from '@angular/material'; 
import { FlexLayoutModule } from '@angular/flex-layout'; 
import { SecurityModule, SecurityService } from '@savantly/ngx-security'; 

@NgModule({ 
    imports: [ 
    CommonModule, 
    MdMenuModule, MdToolbarModule, MdButtonModule, FlexLayoutModule, SecurityModule 
    ], 
    exports: [ 
    CommonModule, 
    MdMenuModule, MdToolbarModule, MdButtonModule, FlexLayoutModule, 
    SecurityModule, 
    MenuComponent], 
    declarations: [MenuComponent], 
    providers: [] 
}) 
export class MenuModule { 

    static forRoot(options?: any): ModuleWithProviders { 
    if (options && options.securityService) { 
     return { 
     ngModule: MenuModule, 
     providers: [{ 
      provide: MenuService, 
      useFactory: menuServiceFactory, 
      deps: [options.securityService] 
      }] 
     } 
    } else { 
     return { 
     ngModule: MenuModule, 
     providers: [MenuService] 
     }; 
    } 
    } 

    constructor (@Optional() @SkipSelf() parentModule: MenuModule) { 
    if (parentModule) { 
     throw new Error(
     'MenuModule is already loaded. Import it in the AppModule only'); 
    } 
    } 
} 

export function menuServiceFactory(_securityService: SecurityService): MenuService { 
    return new MenuService(_securityService); 
} 

Answer 1

隨着@yurzui幫助 - 這是重構模塊 -

import { NgModule, ModuleWithProviders, SkipSelf, Optional } from '@angular/core'; 
import { CommonModule } from '@angular/common'; 
import { MenuComponent } from './menu.component'; 
import { MenuService } from './menu.service'; 
import { MdMenuModule, MdToolbarModule, MdButtonModule } from '@angular/material'; 
import { FlexLayoutModule } from '@angular/flex-layout'; 
import { SecurityModule, SecurityService } from '@savantly/ngx-security'; 

@NgModule({ 
    imports: [ 
    CommonModule, 
    MdMenuModule, MdToolbarModule, MdButtonModule, FlexLayoutModule, SecurityModule 
    ], 
    exports: [ 
    CommonModule, 
    MdMenuModule, MdToolbarModule, MdButtonModule, FlexLayoutModule, 
    SecurityModule, 
    MenuComponent], 
    declarations: [MenuComponent], 
    providers: [] 
}) 
export class MenuModule { 

    static forRoot({securityService = SecurityService}: {securityService?: SecurityService} = {}): ModuleWithProviders { 
    return { 
     ngModule: MenuModule, 
     providers: [{ 
      provide: MenuService, 
      useFactory: menuServiceFactory, 
      deps: [securityService] 
      }] 
     }; 
    } 

    constructor (@Optional() @SkipSelf() parentModule: MenuModule) { 
    if (parentModule) { 
     throw new Error(
     'MenuModule is already loaded. Import it in the AppModule only'); 
    } 
    } 
} 

export function menuServiceFactory(_securityService: SecurityService): MenuService { 
    return new MenuService(_securityService); 
}