.NET MVC Expert Skill

Trigger On

• The user requests to create, debug, refactor, or review ASP.NET Core MVC applications.
• The project contains Views and Controllers directories and inherits from Controller (not ControllerBase).
• The target framework is .NET 6.0 (LTS) and above.
• There is a need to optimize Server-Side Rendering (SSR) performance or improve view organizational structure.

Workflow

1. Perceive (Architecture Awareness):

• Check .csproj to identify TargetFramework.
• Analyze Views/Shared to confirm existing configurations for layouts and partial views.
• Identify whether Tag Helpers and static resource versioning are enabled.

1. Reason (Planning Phase):

• Evaluate whether complex Partial Views need to be migrated to View Components.
• Determine whether custom Tag Helpers are needed to simplify UI logic.
• Choose an appropriate ViewModel organization method based on project scale.

1. Act (Execution Phase):

• Write high-quality controllers and strongly-typed views.
• Implement data validation (Data Annotations) and integrate them into ViewModels.
• Configure and use Tag Helpers to ensure the semantic correctness of forms and links.

1. Validate (Standard Validation):

• Validate whether page rendering conforms to the expected HTML structure.
• Check whether model validation correctly operates on both the frontend and backend.
• Ensure Antiforgery tokens are correctly applied to all state-modifying requests.

Feature Roadmap (.NET 6 - 10)

.NET 6 & 7 (Foundation)

• Tag Helpers: Declarative HTML attribute extensions.
• View Components: Logic-driven UI block modularization.
• Cache Tag Helper: Server-side view fragment caching.
• Nullable Views: Better Razor null safety support.

.NET 8 & 9 (Productivity)

• Blazor Integration: Hybrid development support for MVC and Blazor components.
• Antiforgery Improvements: Global anti-forgery automatic validation optimization.
• Keyed Services in Controllers: Finer-grained dependency injection support.
• Native AOT for MVC: Metadata compilation optimization tailored for AOT.

.NET 10+ (Version-Specific Features)

• Extension Members for IHtmlHelper: Extending view helper functions.
• Advanced Serialization in Views: Performance optimization for large view models.

Coding Standards

• Strongly Typed Views: All views must have an explicit @model.
• ViewModel Separation: Strictly prohibit exposing database entities directly to views.
• Naming: View models must end with ViewModel, action methods prioritize asynchronous patterns.
• Formatting: Follow the Allman style and use Tag Helpers instead of HTML Helpers.

Deliver

• Version-Optimized MVC Code: Provide modernized controllers, models, and views suitable for the target version.
• UI Architecture Suggestions: Provide design suggestions for view components and Tag Helpers.
• Validation Logic: Provide a complete model validation and error prompting implementation plan.

Validate

• Ensure the code complies with C# 10+ syntax standards.
• Validate endpoints correctly handle model validation failures and return form states.
• Confirm static resources and scripts are correctly cached via asp-append-version.

Documentation

Official References

• Overview of ASP.NET Core MVC
• Tag Helpers in ASP.NET Core
• View components in ASP.NET Core

Internal References

• MVC Coding Style and Naming Conventions
• MVC Anti-Patterns and Best Practices
• MVC Modern Patterns Guide