In the same time when first object-oriented languages were emerging, another concept inspired by general relativity and quantum mechanics was taking shape – actor model. In general terms, the Actor model was defined 1973. and was developed on a platform of multiple independent processors in a network. Similar to the object-oriented approach, this essentially mathematical model, revolved around the concept of actors. An actor is the smallest structural unit of Actor model, and just like objects, they encapsulate data and behavior. In difference to objects, however, actors communicate with each other exclusively trough messages. Messages in actors are processed in a serial manner. According to the full definition of actors, they can do three things:

• send a finite number of messages to other actors
  
• create a finite number of new actors
  
• designate the behavior to be used for the next message it receives 
  

98.css is a CSS library for building interfaces that look like Windows 98. 

css-flip index.css > index.ltr.css

• ...
• Spam Filters 
  
• Sending Legally 
  
• Email Client CSS Support 
  
• Responsive Email 
  
• Client-specific CSS Styles 
  
• ...

In this post I described the problem that by default, DataAnnotation validation doesn't recursively inspect all properties in an object for DataAnnotation attributes. There are several solutions to this problem, but in this post I used the MiniValidation library from Damian Edwards. This simple library provides a convenience wrapper around DataAnnotation validation, as well as providing features like recursive validation. Finally I showed how you can replace the built-in DataAnnotation validation with a MiniValidation-based validator

var builder = WebApplication.CreateBuilder(args);

builder.Services.AddOptions<MySettings>()
    .BindConfiguration("MySettings")
    .ValidateMiniValidation() // 👈 Replace with mini validation
    .ValidateOnStart();

var app = builder.Build();

OptionsValidationException: 
  DataAnnotation validation failed for 'MySettings' member: 'Nested.Value' with errors: 'The Value field is required.'.; 
  DataAnnotation validation failed for 'MySettings' member: 'Nested.Count' with errors: 'The field Count must be between 1 and 100.'.
Microsoft.Extensions.Options.OptionsFactory<TOptions>.Create(string name)
Microsoft.Extensions.Options.OptionsMonitor<TOptions>+<>c__DisplayClass10_0.<Get>b__0()

The creator of C++, Bjarne Stroustrup, shares some valuable life advice that, let’s face it, all developers, no matter their years of experience could use. According to Bjarne, ‘You can’t just do code’, you need to develop more skills if you want to be a well-rounded successful developer. Watch this unreleased interview if you want some inspiration and guidance on your developer journey from one of the OGs.