Metadata-Driven Network Logic with HttpContext

Snippet

Metadata-Driven Network Logic with HttpContext

Functional interceptors in Angular can utilize `HttpContext` to receive specific instructions from the calling service. By defining `HttpContextToken`s, you can pass metadata (like caching flags or retry policies) through the HTTP pipeline without polluting the URL or headers. This allows for highly flexible and reusable middleware.

snippet.js
javascript
import { HttpContext, HttpContextToken, HttpInterceptorFn } from '@angular/common/http';
 
export const IS_CACHE_ENABLED = new HttpContextToken<boolean>(() => false);
 
export const cacheInterceptor: HttpInterceptorFn = (req, next) => {
  if (req.context.get(IS_CACHE_ENABLED)) {
    console.log('Caching logic triggered for:', req.url);
  }
  return next(req);
};

angular

Breakdown

export const IS_CACHE_ENABLED = new HttpContextToken<boolean>(() => false);

Creates a unique token for passing boolean metadata through HTTP requests.

if (req.context.get(IS_CACHE_ENABLED))

Retrieves the value of the token from the request context to decide on interceptor logic.

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Metadata-Driven Network Logic with HttpContext

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