Angular 2中的全局管道 [英] Global pipe in Angular 2

问题描述

我想在所有应用程序中使用管道.根据我在Angular文档和Internet中阅读的内容，如果我在根模块声明中声明一个管道，则该管道将在所有应用程序中可用.我有这个AppModule代码:

I want to make a pipe available in all the app. Acording with what I read in the Angular docs and internet, if I declare a pipe into the root module declaratios, it make's the pipe available in all the application. I have this AppModule code:

@NgModule({
  imports:      [ BrowserModule, NavbarModule],
  declarations: [ AppComponent, TranslatePipe],
  bootstrap:    [ AppComponent],
})
export class AppModule { }

这对于子模块:

@NgModule({
  imports:      [ CommonModule],
  declarations: [ NavbarMenuComponent],//<---Call the pipe in this component
})

export class NavbarModule { }

管道:

@Pipe({
    name: 'translate',
    pure: false
})

export class TranslatePipe implements PipeTransform {
    constructor() { }

    transform(value: string, args: any[]): any {
        return value + " translated";
    }
}

但是当我在NavbarMenuComponent模板上调用管道时，会引发此错误:

But whe I call the pipe on the NavbarMenuComponent template it thows this error:

找不到管道"translate""

'The pipe "translate" could not be found'

如果我在子模块声明中声明该管道有效，但是我需要使该管道成为全局管道，因此当应用程序长大时，我不需要在所有模块中都声明该管道(以及其他全局管道) .有没有办法使管道成为全局管道?

If I declare the pipe in the child module declarations it works,but I need to make the pipe global, so when the app grows up, I don't need to declare this pipe(and other global pipes) in all modules. Is there a way to make the pipe global?

推荐答案

您需要将包含管道(并在declarations: []和exports: []中具有管道)的模块添加到您当前模块的>，然后在当前模块中可用.

You need to add the module that contains the pipe (and has it in declarations: [] and exports: []) to imports: [...] of your current module, then it's available in the current module.

@NgModule({
  imports:      [ CommonModule],
  declarations: [ TranslatePipe],
  exports:      [ TranslatePipe],
})
export class TranslateModule { }

@NgModule({
  imports:      [ CommonModule, TranslateModule],
  declarations: [ NavbarMenuComponent]
})
export class NavbarModule { }

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