The day before yesterday, we added content in `Blog.razor` to display both authorized and unauthorized views. However, if the unauthorized content to be displayed is the same across the system, writing it in every component would be a waste of time. We can use `App.razor` to handle unified presentation.
Earlier, we mentioned `UserAuthentication()` and `UserAuthorization()`. The difference is that the former is used to verify who the user is, and the latter determines what the user can do.
Yesterday's authentication only targeted the Identity system and did not include our logs.
Today, we'll implement the authentication part.
When developing a system, logging is very important. It hasn't been mentioned before; the author only recently thought of it, so let's implement it!
In most websites, uploading images is also a very important feature. Today we will practice it.
Suppose there is a situation: there is one log entry, and before adding the second one and submitting, you want to delete the first one. What will happen then?
Next, we will talk about database-related content, focusing on ASP.NET Core and EF Core. Only if there is a need to modify the page, we will mention Blazor. This part will take up more space.
We now have basic logs, but every time we finish inputting and reload the page, the data is reset because these data only exist in the browser and are not actually stored in the database. To save them, we need to connect to the database.
Sometimes we want to apply individual styles to different components. But if we write all CSS classes in `wwwroot/css/site.css`, or modify styles for a specific element, it may cause a change to affect all components. This kind of global conflict must be avoided, but how should we do it?