What steps are necessary to integrate barrel file imports with my Angular 2 application?

Following the Angular 2 style guideline 04-10 Create and Import Barrels can be challenging, as it may lead to unexpected file loading issues. When running my app, I noticed that Angular attempts to load a non-existent file named "my-component-name-here.js". To demonstrate this problem, I made changes to the Angular 2 sample app, incorporating a barrel file which resulted in a 404 error.

To address this issue, I organized the heroes component files into a separate folder named heroes. In this folder, I created a new file called heroes/index.ts:

export * from './heroes/heroes.component';

Subsequently, I modified the import statement in app.component.ts to:

import { HeroesComponent } from './heroes';

Upon attempting to load the app, an error was observed in the developer console:

Error: Error: XHR error (404 Not Found) loading app/heroes.ts(…)

A Plunkr demonstrating this issue is available here: http://plnkr.co/edit/YXY0PwuFot1g1s6qTqDt?p=preview

This problem seems to be related to SystemJS, but my understanding of it is limited. Any assistance in resolving this would be greatly appreciated. Thank you in advance!

angulartypescriptsystemjs

Answer №1

To get the barrel working, you need to implement a few changes:

index.ts

   export * from './heroes.component';

systemjs.config.js

Add the following entry to map:

  'heroes':                     'app/heroes',

Next, add this entry under packages:

  'heroes': { main: 'index.ts',  defaultExtension: 'ts' },

This should resolve the issue with the barrel, however, it may not resolve all your problems as there is also a reference to hero-detail inside the heroes component that needs attention.

Answer №2

From what I have observed in your Plunkr example, it seems that the HeroesComponent class is situated inside the app/heroes/heroes.component.ts file. Therefore, my suggestion would be to make use of the following code snippet:

import { HeroesComponent } from './heroes.component';

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