Sometimes, we need to get a file posted from the client side and want to re-send the file to another server. This is slightly different than when we write a front-end code, where FormData is a standard web API, and we can use it directly, while in Nodejs context, we…

A typical use case of expand and reduce operator, with example and explanation provided. RXJS has many operators, all of them have their own particular use cases. If you are stuck on a particular real world situation, chances are RXJS has an operator for you! …

Get more control of routes, make application more flexible. Usually in our code, routes are all pre-defined. We define them as an constant routes variable, and register it into our app-routing.module.ts file. If we have lazy loaded modules, they also have their own routes defined and registered. Each module is…

ShareReplay: share source and replay specified number of emissions on subscription. After reading that, I still don’t know much about it. Probably the most used case we know about ShareReplay is when doing HTTP calls, we can call API once, and use ShareReplay(1) to give the results to other subscribers…

To add some custom logic before application starts Why we need it It’s common that before an application starts, it needs to know in advance quite a few configurations, such as what’s the baseURL of http call, what's the port number etc. These configurations can also differ between defferent environtments (dev or prod). In…

You might be wondering why we should self-hosting fonts and icons. Isn’t it more common to just link to a public CDN address for fonts and icons? We used to think that it will have a lot of advantages over self-hosting such as: It’s convenient. Just copy the CDN address…

Angular animation gives us a way to add animations to our application and make it more fun and straightforward to use. Typically we would start by adding the animations property inside the @component metadata, and define our animation states and styles there, so that our component has a defined animation.

Change detection By default Angular runs change detection automatically for us. It checks for all components and child components when anything from a click event to an Input binding changes, which is not quite efficient with a big and complicated app. ChangeDetectionStrategy.onPush …