Check console for events.
`,\n})\nexport class AppComponent implements OnInit {\n constructor(private sseClient: SseClient) {}\n\n ngOnInit(): void {\n const headers = new HttpHeaders().set('Authorization', `Basic YWRtaW46YWRtaW4=`);\n\n // Example of subscribing to an SSE stream with custom options and POST method\n this.sseClient.stream(\n '/api/subscribe', // Replace with your SSE endpoint\n { keepAlive: true, reconnectionDelay: 1_000, responseType: 'event' },\n { headers },\n 'POST'\n ).subscribe({\n next: (event) => {\n if (event.type === 'error') {\n const errorEvent = event as ErrorEvent;\n console.error('SSE Error Event:', errorEvent.error, errorEvent.message);\n } else {\n const messageEvent = event as MessageEvent;\n console.info(`SSE Message (${messageEvent.type}):`, messageEvent.data);\n }\n },\n error: (err) => {\n console.error('SSE Subscription Error:', err);\n },\n complete: () => {\n console.log('SSE Stream Completed.');\n }\n });\n }\n}","lang":"typescript","description":"Demonstrates injecting the `SseClient` service, subscribing to an SSE stream with custom options (keep-alive, reconnection delay, event response type), including HTTP headers for authorization, and using a POST method. It also shows handling both `MessageEvent` and `ErrorEvent` responses within the subscription."},"warnings":[{"fix":"Always check the `peerDependencies` in `package.json` or the changelog for `ngx-sse-client` to ensure compatibility with your Angular version before upgrading. Upgrade `ngx-sse-client` to the major version that matches your Angular version.","message":"Major versions of `ngx-sse-client` are tightly coupled with specific Angular versions. Upgrading Angular often requires a corresponding `ngx-sse-client` major version upgrade, which can introduce breaking changes. For example, v21.0.0 requires Angular >=21.0.0.","severity":"breaking","affected_versions":">=17.0.0"},{"fix":"For comprehensive error handling, especially during development or for robust applications, use `responseType: 'event'`. This allows you to differentiate between `MessageEvent` and `ErrorEvent` and react to stream errors. Only use `responseType: 'text'` if you are certain your server will not send error events or if you prefer to handle all stream interruptions as completion events.","message":"When `responseType` is set to `'text'`, the library will only return the message data. No errors will be propagated through the Observable's error channel or returned as `ErrorEvent` types within the stream, effectively suppressing error handling.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Ensure you call `.unsubscribe()` on the `Subscription` object obtained from `sseClient.stream().subscribe()` when the component or service using it is destroyed or no longer needs the stream. For Angular components, this typically means implementing `ngOnDestroy`.","message":"If `keepAlive` is set to `true`, the SSE connection will automatically attempt to reconnect if it's closed (e.g., by timeout or completion). To explicitly terminate the stream, you *must* `unsubscribe` from the Observable. Failure to do so will result in continuous reconnection attempts, potentially consuming resources.","severity":"gotcha","affected_versions":">=1.0.0"},{"fix":"Configure your proxy server (e.g., Nginx) to disable buffering for SSE endpoints. Common Nginx configurations include `proxy_buffering off;` and `proxy_set_header Connection '';` for the SSE location. Also, ensure your application server sends `X-Accel-Buffering: no` header.","message":"SSE connections can be buffered by intermediate proxies or web servers like Nginx, leading to delayed delivery of events. This can negate the real-time benefits of SSE.","severity":"gotcha","affected_versions":">=1.0.0"}],"env_vars":null,"last_verified":"2026-04-22T00:00:00.000Z","next_check":"2026-07-21T00:00:00.000Z","problems":[{"fix":"Add `SseClient` to the `providers` array in your `AppModule` (or a feature module where it's used) to make it injectable: `providers: [SseClient]`.","cause":"The `SseClient` service has not been provided in your Angular application's module or component hierarchy.","error":"Error: NG0201: No provider for SseClient!"},{"fix":"Ensure your `ngx-sse-client` version is up-to-date (currently v21.0.0 for Angular 21) and that your `stream` method call matches the signature of the installed version. You may need to update the library: `npm install ngx-sse-client@latest`.","cause":"This error can occur if you are using an older version of `ngx-sse-client` where the `stream` method had fewer parameters, but your code is written for a newer version that accepts more arguments (e.g., HTTP method and request options).","error":"Expected 1-2 arguments, but got 4."},{"fix":"Use type guards or type assertions within your subscription callback to correctly infer the type of the event. For example: `if (event.type === 'error') { const errorEvent = event as ErrorEvent; /* ... */ } else { const messageEvent = event as MessageEvent; /* ... */ }`.","cause":"When `responseType` is `'event'`, the `subscribe` callback receives an `Event` object, which needs to be type-asserted to `MessageEvent` or `ErrorEvent` to access specific properties like `data` or `message`.","error":"Property 'type' does not exist on type 'unknown'."}],"ecosystem":"npm","meta_description":null}