ABP Framework Patterns

Master ABP Framework patterns for building maintainable, scalable applications following Domain-Driven Design principles.

This skill orchestrates three focused skills:

Quick Reference

Architecture Layers

Domain.Shared    → Constants, enums, shared types
Domain           → Entities, repositories, domain services, domain events
Application.Contracts → DTOs, application service interfaces
Application      → Application services, mapper profiles, validators
EntityFrameworkCore → DbContext, repository implementations
HttpApi          → Controllers (auto-generated by ABP)
HttpApi.Host     → Startup, configuration

Common Patterns

Entity Patterns

Standard Entity with Encapsulation

public class Patient : FullAuditedAggregateRoot<Guid>
{
    public string FirstName { get; private set; } = string.Empty;
    public string LastName { get; private set; } = string.Empty;
    public string Email { get; private set; } = string.Empty;
    public bool IsActive { get; private set; } = true;

    // Required for EF Core
    protected Patient() { }

    public Patient(Guid id, string firstName, string lastName, string email) : base(id)
    {
        SetName(firstName, lastName);
        SetEmail(email);
    }

    public void SetName(string firstName, string lastName)
    {
        FirstName = Check.NotNullOrWhiteSpace(firstName, nameof(firstName), maxLength: PatientConsts.MaxFirstNameLength);
        LastName = Check.NotNullOrWhiteSpace(lastName, nameof(lastName), maxLength: PatientConsts.MaxLastNameLength);
    }

    public void SetEmail(string email)
    {
        Email = Check.NotNullOrWhiteSpace(email, nameof(email), maxLength: PatientConsts.MaxEmailLength);
    }

    public void Activate() => IsActive = true;
    public void Deactivate() => IsActive = false;
}

Constants Class

// Domain.Shared/{Feature}/{Entity}Consts.cs
namespace {ProjectName}.{Feature};

public static class PatientConsts
{
    public const int MaxFirstNameLength = 100;
    public const int MaxLastNameLength = 100;
    public const int MaxEmailLength = 256;
}

AppService Patterns

Standard AppService (Recommended)

[Authorize({ProjectName}Permissions.Patients.Default)]
public class PatientAppService : ApplicationService, IPatientAppService
{
    private readonly IRepository<Patient, Guid> _patientRepository;

    public PatientAppService(IRepository<Patient, Guid> patientRepository)
    {
        _patientRepository = patientRepository;
    }

    public async Task<PagedResultDto<PatientDto>> GetListAsync(GetPatientsInput input)
    {
        var queryable = await _patientRepository.GetQueryableAsync();

        var query = queryable
            .WhereIf(!input.Filter.IsNullOrWhiteSpace(),
                x => x.FirstName.Contains(input.Filter!) || x.LastName.Contains(input.Filter!))
            .WhereIf(input.IsActive.HasValue, x => x.IsActive == input.IsActive);

        var totalCount = await AsyncExecuter.CountAsync(query);
        var patients = await AsyncExecuter.ToListAsync(
            query
                .OrderBy(input.Sorting.IsNullOrWhiteSpace() ? nameof(Patient.LastName) : input.Sorting)
                .PageBy(input));

        return new PagedResultDto<PatientDto>(totalCount, patients.ToDto());
    }

    public async Task<PatientDto> GetAsync(Guid id)
    {
        var patient = await _patientRepository.GetAsync(id);
        return patient.ToDto();
    }

    [Authorize({ProjectName}Permissions.Patients.Create)]
    public async Task<PatientDto> CreateAsync(CreatePatientDto input)
    {
        var patient = new Patient(
            GuidGenerator.Create(),
            input.FirstName,
            input.LastName,
            input.Email);

        await _patientRepository.InsertAsync(patient, autoSave: true);
        return patient.ToDto();
    }

    [Authorize({ProjectName}Permissions.Patients.Edit)]
    public async Task<PatientDto> UpdateAsync(Guid id, UpdatePatientDto input)
    {
        var patient = await _patientRepository.GetAsync(id);

        patient.SetName(input.FirstName, input.LastName);
        patient.SetEmail(input.Email);

        await _patientRepository.UpdateAsync(patient, autoSave: true);
        return patient.ToDto();
    }

    [Authorize({ProjectName}Permissions.Patients.Delete)]
    public async Task DeleteAsync(Guid id)
    {
        await _patientRepository.DeleteAsync(id);
    }
}

CrudAppService Base (For Simple CRUD)

// Use when no custom business logic is needed
public class PatientAppService : CrudAppService<
    Patient,           // Entity
    PatientDto,        // Output DTO
    Guid,              // Primary key
    GetPatientsInput,  // GetList input
    CreatePatientDto,  // Create input
    UpdatePatientDto>, // Update input
    IPatientAppService
{
    public PatientAppService(IRepository<Patient, Guid> repository)
        : base(repository)
    {
    }

    // Override specific methods if needed
    protected override async Task<IQueryable<Patient>> CreateFilteredQueryAsync(GetPatientsInput input)
    {
        var query = await base.CreateFilteredQueryAsync(input);
        return query
            .WhereIf(!input.Filter.IsNullOrWhiteSpace(),
                x => x.FirstName.Contains(input.Filter!));
    }
}

Mapperly Patterns

Static Extension Methods (RECOMMENDED)

// Application/{Feature}/{Entity}Mappers.cs
using Riok.Mapperly.Abstractions;

namespace {ProjectName}.{Feature};

[Mapper]
public static partial class PatientMappers
{
    // Single entity mapping
    public static partial PatientDto ToDto(this Patient patient);

    // Collection mapping
    public static partial List<PatientDto> ToDto(this List<Patient> patients);

    // IEnumerable for LINQ
    public static partial IEnumerable<PatientDto> ToDto(this IEnumerable<Patient> patients);

    // Update entity from DTO (ignores Id)
    [MapperIgnoreTarget(nameof(Patient.Id))]
    public static partial void UpdateFrom(this Patient patient, UpdatePatientDto dto);
}

// Usage in AppService (no injection needed):
return patient.ToDto();
return patients.ToDto().ToList();

Instance Mapper (Alternative)

// Only if DI is required (e.g., for resolving navigation properties)
[Mapper(RequiredMappingStrategy = RequiredMappingStrategy.None)]
public partial class PatientApplicationMappers
{
    public partial PatientDto Map(Patient patient);
    public partial List<PatientDto> MapList(List<Patient> patients);
}

// Register in Module:
context.Services.AddSingleton<PatientApplicationMappers>();

Permission Patterns

Permission Constants

// Application.Contracts/Permissions/{Entity}Permissions.cs
namespace {ProjectName}.Permissions;

public static class PatientPermissions
{
    public const string GroupName = "{ProjectName}.Patients";

    public const string Default = GroupName;
    public const string Create = GroupName + ".Create";
    public const string Edit = GroupName + ".Edit";
    public const string Delete = GroupName + ".Delete";
}

Permission Definition Provider

public class {ProjectName}PermissionDefinitionProvider : PermissionDefinitionProvider
{
    public override void Define(IPermissionDefinitionContext context)
    {
        var myGroup = context.AddGroup({ProjectName}Permissions.GroupName);

        var patientsPermission = myGroup.AddPermission(
            PatientPermissions.Default,
            L("Permission:Patients"));

        patientsPermission.AddChild(
            PatientPermissions.Create,
            L("Permission:Patients.Create"));

        patientsPermission.AddChild(
            PatientPermissions.Edit,
            L("Permission:Patients.Edit"));

        patientsPermission.AddChild(
            PatientPermissions.Delete,
            L("Permission:Patients.Delete"));
    }

    private static LocalizableString L(string name) =>
        LocalizableString.Create<{ProjectName}Resource>(name);
}

Filter DTO Pattern

Standard Filter DTO

using Volo.Abp.Application.Dtos;

namespace {ProjectName}.{Feature};

public class GetPatientsInput : PagedAndSortedResultRequestDto
{
    // Text search filter
    public string? Filter { get; set; }

    // Status filter
    public bool? IsActive { get; set; }

    // Foreign key filter
    public Guid? DoctorId { get; set; }

    // Date range filters
    public DateTime? FromDate { get; set; }
    public DateTime? ToDate { get; set; }
}

WhereIf Extension Usage

var query = queryable
    .WhereIf(!input.Filter.IsNullOrWhiteSpace(),
        x => x.FirstName.Contains(input.Filter!) ||
             x.LastName.Contains(input.Filter!) ||
             x.Email.Contains(input.Filter!))
    .WhereIf(input.IsActive.HasValue, x => x.IsActive == input.IsActive)
    .WhereIf(input.DoctorId.HasValue, x => x.DoctorId == input.DoctorId)
    .WhereIf(input.FromDate.HasValue, x => x.CreationTime >= input.FromDate)
    .WhereIf(input.ToDate.HasValue, x => x.CreationTime <= input.ToDate);

Best Practices

Do's

1. Entity encapsulation - Use private setters and domain methods
2. Thin AppServices - Orchestrate, don't implement business logic
3. Domain Services - For cross-entity business rules
4. Static Mappers - Use extension methods for cleaner code
5. WhereIf pattern - Clean optional filtering
6. Permission checks - Class-level [Authorize] + method-level for mutations
7. autoSave: true - Use for single operations (avoid extra SaveChanges)
8. Constants classes - Define max lengths in Domain.Shared

Don'ts

1. Don't duplicate authorization - If class has [Authorize], methods with same permission don't need it
2. Don't inject mappers - Use static extension methods instead
3. Don't check null after WhereIf - The .HasValue check handles it
4. Don't use AutoMapper - Use Mapperly for source generation
5. Don't expose entities - Always return DTOs

Code Quality Checklist

Before completing implementation:

• Entity has private setters and domain methods
• Entity has parameterless protected constructor for EF Core
• AppService class has [Authorize(Permission.Default)]
• All mutations have specific [Authorize(Permission.Action)]
• Mapper uses static extension methods pattern
• Filter DTO extends PagedAndSortedResultRequestDto
• Filter uses WhereIf pattern for optional parameters
• Constants defined in Domain.Shared
• Permissions follow {Project}.{Resource}.{Action} pattern
• InsertAsync uses autoSave: true for single operations

Detailed Reference

For comprehensive patterns, see the focused skills:

• abp-entity-patterns - Entity base classes, repositories, domain services, data seeding
• abp-service-patterns - AppServices, DTOs, Mapperly, UoW, Filter DTOs, CommonDependencies
• abp-infrastructure-patterns - Permissions, background jobs, distributed events, multi-tenancy
• abp-contract-scaffolding - Interface and DTO generation for parallel workflows

External Resources

• ABP Documentation: https://docs.abp.io/
• ABP Community: https://community.abp.io/
• ABP GitHub: https://github.com/abpframework/abp
• Mapperly: https://mapperly.riok.app/