Dext Framework Patterns

Dext Framework Patterns (Delphi)

The Dext Framework is a complete ecosystem for Delphi, directly inspired by ASP.NET Core and Spring Boot. It is intended for high-performance corporate development. Unlike Horse or DMVC, Dext embraces Dependency Injection, Minimal APIs with automatic model binding and has its own Entity ORM (Dext.Entity).

This manual provides the conventions that must be followed by the AI ​​when coding with Dext.

Important Note: Dext Framework is not short for DevExpress/DevExtreme visual components, but rather the backend project (https://github.com/cesarliws/dext).

Core Principles

1. Minimal Routing (Minimal APIs): Do not use traditional MVC Controllers unless necessary. Use functional routing syntax (MapGet, MapPost).
2. Auto Model Binding: Get JSON body not via strings and partial conversions, but by delegating strong typing to anonymous route parameters (function(Dto: MyDto): IResult).
3. Integrated DI Container: All interface dependencies must be resolved via App.Services (Injection). Do not use manual factories.
4. Smart ORM (Dext.Entity): Never concatenate SQL.

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1. WebApp Lifecycle and DI

Bootstrap of a Dext API occurs by registering services in the same route pipeline.

program MyAPI;

uses Dext.Web, Services.Interfaces, Services.Implementations;

begin
  var App := WebApplication;
  var Builder := App.Builder;

  //1. Registration of Dependency Injection Services
  App.Services.AddSingleton<IEmailService, TEmailService>;
  App.Services.AddScoped<IOrderRepository, TOrderRepository>;

  //2. Route Mapping
  Builder.MapGet<IResult>('/health', 
    function: IResult
    begin
        Result := Results.Ok('{"status": "ok"}');
    end);

  //3. Start
  App.Run(8080);
end.

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2. Minimal APIs & Model Binding

The preferred way to build REST APIs with Dext is using typed anonymous delegates, with DI dependencies passed in the final arguments.

Create user (Post + DTO Body + Auth)