Angular 2:静态解析符号值时遇到错误.- 我怎样才能把它变成工厂方法? [英] Angular 2 : Error encountered resolving symbol values statically. - How can I turn this into a factory method?

问题描述

安装 Angular-cli 后出现此错误:

After installing Angular-cli I am getting this error:

Error encountered resolving symbol values statically. Function calls are not supported. Consider replacing the function or lambda with a refer
ence to an exported function (position 55:19 in the original .ts file), resolving symbol AppModule in C:/TM-2013/Debt/Debt Platform/Code/main/Think.Debt.Presentation/deb-explorer-with-angular
-cli/src/app/app.module.ts    

在我的 App.Module.ts 中它不喜欢这段代码:

In my App.Module.ts it does not like this section of code:

供应商:[

//   These are needed throughout the site    
AppConfigService,

{ provide: APP_INITIALIZER, useFactory: configServiceFactory, deps: [AppConfigService], multi: true },
{
  provide: HttpService,
  useFactory: (backend: XHRBackend, options: RequestOptions) => {
    return new HttpService(backend, options);
  },
  deps: [XHRBackend, RequestOptions]
}

]、

使用 .load

  { provide: APP_INITIALIZER, useFactory: (config: AppConfigService) => () => config.load(), deps: [AppConfigService], multi: true },
    {
      provide: HttpService,
      useFactory: (backend: XHRBackend, options: RequestOptions) => {
        return new HttpService(backend, options);
      },
      deps: [XHRBackend, RequestOptions]
    }

是否可以将其转换为工厂类，因为它不喜欢当前的用法?

Is it possible to turn this into a factory class as it does not like this current usage?

推荐答案

完全按照建议去做:

// named exported function
export function httpFactory(backend: XHRBackend, options: RequestOptions) {
    return new HttpService(backend, options);
}

export function configServiceFactory(config: AppConfigService) {
    return () => config.load();
}

// after goes declaration of you module with `providers`
// ... skipped ...
{ provide: APP_INITIALIZER, useFactory: configServiceFactory, deps: [AppConfigService], multi: true },
{
    provide: HttpService,
    useFactory: httpFactory,  // reference to the function
    deps: [XHRBackend, RequestOptions]
}
// ... skipped ...

这篇关于Angular 2:静态解析符号值时遇到错误.- 我怎样才能把它变成工厂方法?的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！