Web Application Development Tutorial - Part 1: Creating the Server Side
Creating the Solution
Before starting the development, create a new solution named Acme.BookStore
and run it by following the getting started tutorial.
After Creating the Solution
Installing the Client-Side Packages
ABP CLI runs the abp install-libs
command behind the scenes to install the required NPM packages for your solution while creating the application.
However, sometimes this command might need to be manually run. For example, you need to run this command, if you have cloned the application, or the resources from node_modules folder didn't copy to wwwroot/libs folder, or if you have added a new client-side package dependency to your solution.
For such cases, run the abp install-libs
command on the root directory of your solution to install all required NPM packages:
abp install-libs
We suggest you install Yarn to prevent possible package inconsistencies, if you haven't installed it yet.
Create the Book Entity
Domain layer in the startup template is separated into two projects:
Acme.BookStore.Domain
contains your entities, domain services and other core domain objects.Acme.BookStore.Domain.Shared
containsconstants
,enums
or other domain related objects that can be shared with clients.
So, define your entities in the domain layer (Acme.BookStore.Domain
project) of the solution.
The main entity of the application is the Book
. Create a Books
folder (namespace) in the Acme.BookStore.Domain
project and add a Book
class inside it:
using System;
using Volo.Abp.Domain.Entities.Auditing;
namespace Acme.BookStore.Books;
public class Book : AuditedAggregateRoot<Guid>
{
public string Name { get; set; }
public BookType Type { get; set; }
public DateTime PublishDate { get; set; }
public float Price { get; set; }
}
- ABP has two fundamental base classes for entities:
AggregateRoot
andEntity
. Aggregate Root is a Domain Driven Design concept which can be thought as a root entity that is directly queried and worked on (see the entities document for more). - The
Book
entity inherits from theAuditedAggregateRoot
which adds some base auditing properties (likeCreationTime
,CreatorId
,LastModificationTime
...) on top of theAggregateRoot
class. ABP automatically manages these properties for you. Guid
is the primary key type of theBook
entity.
This tutorial leaves the entity properties with public get/set for the sake of simplicity. See the entities document if you want to learn more about DDD best practices.
BookType Enum
The Book
entity uses the BookType
enum. Create a Books
folder (namespace) in the Acme.BookStore.Domain.Shared
project and add a BookType
inside it:
namespace Acme.BookStore.Books;
public enum BookType
{
Undefined,
Adventure,
Biography,
Dystopia,
Fantastic,
Horror,
Science,
ScienceFiction,
Poetry
}
The final folder/file structure should be as shown below:
Add the Book Entity to the DbContext
EF Core requires that you relate the entities with your DbContext
. The easiest way to do so is adding a DbSet
property to the BookStoreDbContext
class in the Acme.BookStore.EntityFrameworkCore
project, as shown below:
public class BookStoreDbContext : AbpDbContext<BookStoreDbContext>
{
public DbSet<Book> Books { get; set; }
//...
}
Map the Book Entity to a Database Table
Navigate to the OnModelCreating
method in the BookStoreDbContext
class and add the mapping code for the Book
entity:
using Acme.BookStore.Books;
...
namespace Acme.BookStore.EntityFrameworkCore;
public class BookStoreDbContext :
AbpDbContext<BookStoreDbContext>,
IIdentityDbContext,
ITenantManagementDbContext
{
...
protected override void OnModelCreating(ModelBuilder builder)
{
base.OnModelCreating(builder);
/* Include modules to your migration db context */
builder.ConfigurePermissionManagement();
...
/* Configure your own tables/entities inside here */
builder.Entity<Book>(b =>
{
b.ToTable(BookStoreConsts.DbTablePrefix + "Books",
BookStoreConsts.DbSchema);
b.ConfigureByConvention(); //auto configure for the base class props
b.Property(x => x.Name).IsRequired().HasMaxLength(128);
});
}
}
BookStoreConsts
has constant values for the schema and table prefixes for your tables. You don't have to use it, but it's suggested to control the table prefixes in a single point.- The
ConfigureByConvention()
method gracefully configures/maps the inherited properties. Always use it for all your entities.
Add Database Migration
The startup solution is configured to use Entity Framework Core Code First Migrations. Since we've changed the database mapping configuration, we should create a new migration and apply changes to the database.
Open a command-line terminal in the directory of the Acme.BookStore.EntityFrameworkCore
project and type the following command:
dotnet ef migrations add Created_Book_Entity
This will add a new migration class to the project:
If you are using Visual Studio, you may want to use the
Add-Migration Created_Book_Entity
andUpdate-Database
commands in the Package Manager Console (PMC). In this case, ensure thatAcme.BookStore.EntityFrameworkCore
is the startup project in Visual Studio andAcme.BookStore.EntityFrameworkCore
is the Default Project in PMC.
Add Sample Seed Data
It's good to have some initial data in the database before running the application. This section introduces the Data Seeding system of the ABP. You can skip this section if you don't want to create the data seeding, but it is suggested to follow along and learn this useful ABP feature.
Create a class that implements the IDataSeedContributor
interface in the *.Domain
project by copying the following code:
using System;
using System.Threading.Tasks;
using Acme.BookStore.Books;
using Volo.Abp.Data;
using Volo.Abp.DependencyInjection;
using Volo.Abp.Domain.Repositories;
namespace Acme.BookStore;
public class BookStoreDataSeederContributor
: IDataSeedContributor, ITransientDependency
{
private readonly IRepository<Book, Guid> _bookRepository;
public BookStoreDataSeederContributor(IRepository<Book, Guid> bookRepository)
{
_bookRepository = bookRepository;
}
public async Task SeedAsync(DataSeedContext context)
{
if (await _bookRepository.GetCountAsync() <= 0)
{
await _bookRepository.InsertAsync(
new Book
{
Name = "1984",
Type = BookType.Dystopia,
PublishDate = new DateTime(1949, 6, 8),
Price = 19.84f
},
autoSave: true
);
await _bookRepository.InsertAsync(
new Book
{
Name = "The Hitchhiker's Guide to the Galaxy",
Type = BookType.ScienceFiction,
PublishDate = new DateTime(1995, 9, 27),
Price = 42.0f
},
autoSave: true
);
}
}
}
- This code simply uses the
IRepository<Book, Guid>
(the default repository) to insert two books to the database in case there weren't any books in it.
Update the Database
Run the Acme.BookStore.DbMigrator
application to update the database:
.DbMigrator
is a console application that can be run to migrate the database schema and seed the data on development and production environments.
Create the Application Service
The application layer is separated into two projects:
Acme.BookStore.Application.Contracts
contains your DTOs and application service interfaces.Acme.BookStore.Application
contains the implementations of your application services.
In this section, you will create an application service to get, create, update and delete books using the CrudAppService
base class of the ABP.
BookDto
CrudAppService
base class requires to define the fundamental DTOs for the entity. Create a Books
folder (namespace) in the Acme.BookStore.Application.Contracts
project and add a BookDto
class inside it:
using System;
using Volo.Abp.Application.Dtos;
namespace Acme.BookStore.Books;
public class BookDto : AuditedEntityDto<Guid>
{
public string Name { get; set; }
public BookType Type { get; set; }
public DateTime PublishDate { get; set; }
public float Price { get; set; }
}
- DTO classes are used to transfer data between the presentation layer and the application layer. See the Data Transfer Objects document for more details.
- The
BookDto
is used to transfer the book data to the presentation layer in order to show the book information on the UI. - The
BookDto
is derived from theAuditedEntityDto<Guid>
which has audit properties just like theBook
entity defined above.
It will be needed to map the Book
entities to the BookDto
objects while returning books to the presentation layer. AutoMapper library can automate this conversion when you define the proper mapping. The startup template comes with AutoMapper pre-configured. So, you can just define the mapping in the BookStoreApplicationAutoMapperProfile
class in the Acme.BookStore.Application
project:
using Acme.BookStore.Books;
using AutoMapper;
namespace Acme.BookStore;
public class BookStoreApplicationAutoMapperProfile : Profile
{
public BookStoreApplicationAutoMapperProfile()
{
CreateMap<Book, BookDto>();
}
}
See the object to object mapping document for details.
CreateUpdateBookDto
Create a CreateUpdateBookDto
class in the Books
folder (namespace) of the Acme.BookStore.Application.Contracts
project:
using System;
using System.ComponentModel.DataAnnotations;
namespace Acme.BookStore.Books;
public class CreateUpdateBookDto
{
[Required]
[StringLength(128)]
public string Name { get; set; } = string.Empty;
[Required]
public BookType Type { get; set; } = BookType.Undefined;
[Required]
[DataType(DataType.Date)]
public DateTime PublishDate { get; set; } = DateTime.Now;
[Required]
public float Price { get; set; }
}
- This
DTO
class is used to get a book information from the user interface while creating or updating the book. - It defines data annotation attributes (like
[Required]
) to define validations for the properties.DTO
s are automatically validated by the ABP.
As done to the BookDto
above, we should define the mapping from the CreateUpdateBookDto
object to the Book
entity. The final class will be as shown below:
using Acme.BookStore.Books;
using AutoMapper;
namespace Acme.BookStore;
public class BookStoreApplicationAutoMapperProfile : Profile
{
public BookStoreApplicationAutoMapperProfile()
{
CreateMap<Book, BookDto>();
CreateMap<CreateUpdateBookDto, Book>();
}
}
IBookAppService
Next step is to define an interface for the application service. Create an IBookAppService
interface in the Books
folder (namespace) of the Acme.BookStore.Application.Contracts
project:
using System;
using Volo.Abp.Application.Dtos;
using Volo.Abp.Application.Services;
namespace Acme.BookStore.Books;
public interface IBookAppService :
ICrudAppService< //Defines CRUD methods
BookDto, //Used to show books
Guid, //Primary key of the book entity
PagedAndSortedResultRequestDto, //Used for paging/sorting
CreateUpdateBookDto> //Used to create/update a book
{
}
- Defining interfaces for the application services are not required by the framework. However, it's suggested as a best practice.
ICrudAppService
defines common CRUD methods:GetAsync
,GetListAsync
,CreateAsync
,UpdateAsync
andDeleteAsync
. It's not required to extend it. Instead, you could inherit from the emptyIApplicationService
interface and define your own methods manually (which will be done for the authors in the next parts).- There are some variations of the
ICrudAppService
where you can use separated DTOs for each method (like using different DTOs for create and update).
BookAppService
It is time to implement the IBookAppService
interface. Create a new class, named BookAppService
in the Books
namespace (folder) of the Acme.BookStore.Application
project:
using System;
using Volo.Abp.Application.Dtos;
using Volo.Abp.Application.Services;
using Volo.Abp.Domain.Repositories;
namespace Acme.BookStore.Books;
public class BookAppService :
CrudAppService<
Book, //The Book entity
BookDto, //Used to show books
Guid, //Primary key of the book entity
PagedAndSortedResultRequestDto, //Used for paging/sorting
CreateUpdateBookDto>, //Used to create/update a book
IBookAppService //implement the IBookAppService
{
public BookAppService(IRepository<Book, Guid> repository)
: base(repository)
{
}
}
BookAppService
is derived fromCrudAppService<...>
which implements all the CRUD (create, read, update, delete) methods defined by theICrudAppService
.BookAppService
injectsIRepository<Book, Guid>
which is the default repository for theBook
entity. ABP automatically creates default repositories for each aggregate root (or entity). See the repository document.BookAppService
usesIObjectMapper
service (see) to map theBook
objects to theBookDto
objects andCreateUpdateBookDto
objects to theBook
objects. The Startup template uses the AutoMapper library as the object mapping provider. We have defined the mappings before, so it will work as expected.
Auto API Controllers
In a typical ASP.NET Core application, you create API Controllers to expose the application services as HTTP API endpoints. This allows browsers or 3rd-party clients to call them over HTTP.
ABP can automagically configure your application services as MVC API Controllers by convention.
Swagger UI
The startup template is configured to run the Swagger UI using the Swashbuckle.AspNetCore library. Run the application (Acme.BookStore.Web
) by pressing CTRL+F5
and navigate to https://localhost:<port>/swagger/
on your browser. Replace <port>
with your own port number.
You will see some built-in service endpoints as well as the Book
service and its REST-style endpoints:
Swagger has a nice interface to test the APIs.
If you try to execute the [GET] /api/app/book
API to get a list of books, the server returns such a JSON result:
{
"totalCount": 2,
"items": [
{
"name": "The Hitchhiker's Guide to the Galaxy",
"type": 7,
"publishDate": "1995-09-27T00:00:00",
"price": 42,
"lastModificationTime": null,
"lastModifierId": null,
"creationTime": "2020-07-03T21:04:18.4607218",
"creatorId": null,
"id": "86100bb6-cbc1-25be-6643-39f62806969c"
},
{
"name": "1984",
"type": 3,
"publishDate": "1949-06-08T00:00:00",
"price": 19.84,
"lastModificationTime": null,
"lastModifierId": null,
"creationTime": "2020-07-03T21:04:18.3174016",
"creatorId": null,
"id": "41055277-cce8-37d7-bb37-39f62806960b"
}
]
}
That's pretty cool since we haven't written a single line of code to create the API controller, but now we have a fully working REST API!