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ngx-http-resilience

Angular HttpInterceptor that provides resiliency capabilities

Getting Started

Installation

npm install ngx-http-resilience

Usage

Interceptor Functions

// app.config.ts
import { provideHttpClient, withInterceptors } from '@angular/common/http';
import { ApplicationConfig } from '@angular/core';
import { HttpVisibilityInterceptorError, HttpVisibilityInterceptorHttpEvent, createHttpVisibilityInterceptorFn } from 'ngx-http-resilience';
import { Subject } from 'rxjs';

export const httpEvents$ = new Subject<HttpVisibilityInterceptorHttpEvent<unknown>>();
export const errors$ = new Subject<HttpVisibilityInterceptorError>();
const visibilityInterceptor = createHttpVisibilityInterceptorFn({
  httpEvents$,
  errors$,
});

export const appConfig: ApplicationConfig = {
  providers: [provideHttpClient(withInterceptors([visibilityInterceptor]))],
};

Interceptor Service

// app.config.ts
import { HTTP_INTERCEPTORS } from '@angular/common/http';
import { ApplicationConfig } from '@angular/core';
import { HttpVisibilityInterceptorService } from 'ngx-http-resilience';

export const visibilityInterceptorService = new HttpVisibilityInterceptorService();

export const httpInterceptorProviders = [
  {
    provide: HTTP_INTERCEPTORS,
    useValue: visibilityInterceptorService,
    multi: true,
  },
];

export const appConfig: ApplicationConfig = {
  providers: [httpInterceptorProviders],
};

Visibility

The visibility interceptor provides a stream of http events and errors. This can be used to modify an apps behaviour, such as letting a user know that there are network connectivity issues.

Retry

The retry interceptor allows for retrying failed requests. For example retrying requests that failed due to network connectivity issues.

Every retry interceptor has a retry policy, which determines:

  • Which requests it handles (shouldHandleRequest)
  • Which errors it handles (shouldHandleError)
  • How much time to wait between retries (delay)

Optionally it can also specify a:

  • Maximum number of retries (maxRetries)
  • Maximum time to wait for success (maxDuration)
Function Service

provideHttpClient(
  withInterceptors([
    createHttpRetryInterceptorFn({
      shouldHandleRequest: matchPattern({ url: /example.com/ }),
      shouldHandleError: withStatusCodes(STANDARD_RETRYABLE_STATUS_CODES),
      delay: constantDelay(10, true),
    })
  ])
),
TODO