ASP.NET Core Angular 2 template: Web API method (e.g. WeatherForecasts) called twice on F5

[TarasBanakh]

Installed product versions

• Visual Studio 2015
• This extension: 1.1.37

Description

In ASP.NET Core Angular 2 template the Web API server method WeatherForecasts called twice on browser refresh (F5) of 'http://localhost:5000/fetch-data' page.

Steps to recreate

1. Add System.Threading.Thread.Sleep(TimeSpan.FromSeconds(10)); in the beginning of Web API method WeatherForecasts. (Or just set a breakpoint in WeatherForecasts and debug it).
2. Try to refresh (F5) the 'http://localhost:5000/fetch-data' page.

Current behavior

You will notice that WeatherForecasts is called twice: once on the server during server-side prerendering and once from the browser's javascript after the page has being loaded.

Expected behavior

It should be only called once during server-side prerendering.

[SteveSandersonMS]

This is expected. Unlike the Redux template, the Angular app doesn't have an automatic way to transfer state from server to client.

[freddy01288]

any help for this? I get initial data twice, does anyone know if this happens only in development and not in production ?, it's a serious problem :(