Introduction

We are creating different applications based on different needs. But implementing common and similar structures over and over again, at least in some level. Authorization, Validation, Exception Handling, Logging, Localization, Database Connection Management, Setting Management, Audit Logging are some of these common structures. Also, we are building architectural structures and best practices like Layered and Modular Architecture, Domain Driven Design, Dependency Injection and so on. And trying to develop applications based on some conventions.

Since all of these are very time-consuming and hard to build seperately for every project, many companies create private frameworks. They're developing new applications faster with less bugs using these frameworks. Surely, not all companies that lucky. Most of them have no time, budget and team to develop such frameworks. Even they have possibility to create a framework, it's hard to document, train developers and maintain it.

ASP.NET Boilerplate (ABP) is an open source and well documented application framework started idea of "developing a common framework for all companies and all developers!" It's not just a framework but also provides a strong architectural model based on Domain Driven Design and best practices in mind.

A Quick Sample

Let's investigate a simple class to see ABP's benefits:

public class TaskAppService : ApplicationService, ITaskAppService
{
    private readonly IRepository<Task> _taskRepository;

    public TaskAppService(IRepository<Task> taskRepository)
    {
        _taskRepository = taskRepository;
    }

    [AbpAuthorize(MyPermissions.UpdatingTasks)]
    public async Task UpdateTask(UpdateTaskInput input)
    {
        Logger.Info("Updating a task for input: " + input);

        var task = await _taskRepository.FirstOrDefaultAsync(input.TaskId);
        if (task == null)
        {
            throw new UserFriendlyException(L("CouldNotFoundTheTaskMessage"));
        }

        input.MapTo(task);
    }
}

Here, we see a sample Application Service method. An application service, in DDD, is directly used by presentation layer to perform use cases of the application. We can think that UpdateTask method is called by javascript via AJAX. Let's see ABP's some benefits here:

• Dependency Injection : ABP uses and provides a strong and conventional DI infrastructure. Since this class is an application service, it's conventionally registered to DI container as transient (created per request). It can simply inject all dependencies (as IRepository<Task> in this sample).
• Repository : ABP can create a default repository for each entity (as IRepository<Task> in this example). Default repository has many useful methods as FirstOrDefault used in this example. We can easily extend default repository upon our needs. Repositories abstracts DBMS and ORMs and simplifies data access logic.
• Authorization : ABP can check permissions. It prevents access to UpdateTask method if current user has no "updating task" permission or not logged in. It simplifies authorization using declarative attributes but also has additional ways of authorization.
• Validation : ABP automatically checks if input is null. It also validates all properties of an input based on standard data annotation attributes and custom validation rules. If request is not valid, it throws a proper validation exception.
• Audit Logging : User, browser, IP address, calling service, method, parameters, calling time, execution duration and some other informations are automatically saved for each request based on conventions and configurations.
• Unit Of Work : In ABP, each application service method is assumed as a unit of work as default. It automatically creates a connection and begins a transaction at the beggining of the method. If the method successfully completed without exception, then the transaction is commited and connection is disposed. Even this method uses different repositories or methods, all of them will be atomic (transactional). And all changes on entities are automatically saved when transaction is commited. Thus, we don't even need to call _repository.Update(task) method as shown here.
• Exception Handling : We almost never handle exceptions in ABP in a web application. All exceptions are automatically handled by default. If an exception occurs, ABP automatically logs it and returns a proper result to the client. For example, if this is an AJAX request, the it returns a JSON to client indicates that an error occured. If hides actual exception from client unless the exception is a UserFriendlyException as used in this sample. It also understands and handles errors on client side and show appropriate messages to users.
• Logging : As you see, we can write logs using the Logger object defined in base class. Log4Net is used as default but it's changable or configurable.
• Localization : Notice that we used L method while throwing exception. Thus, it's automatically localized based on current user's culture. Surely, we're defining CouldNotFoundTheTaskMessage in somewhere (see localization document for more).
• Auto Mapping : In the last line, we're using ABP's MapTo extension method to map input properties to entity properties. It uses AutoMapper library to perform mapping. Thus, we can easily map properties from one object to another based on naming conventions.
• Dynamic Web API Layer : TaskAppService is a simple class actually (even no need to deliver from ApplicationService). We generally write a wrapper Web API Controller to expose methods to javascript clients. ABP automatically does that on runtime. Thus, we can use application service methods directly from clients.
• Dynamic Javascript AJAX Proxy : ABP creates javascript proxy methods those make calling application service methods just as simple as calling javascript methods on the client.

We can see benefit of ABP in such a simple class. All these tasks normally take significiant time, but all they are automatically handled by ABP.

What Else

Beside this simple example, ABP provides a strong infrastructure and application model. Here, some other features of ABP:

• Modularity : Provides a strong infrastructure to build reusable modules.
• Data Filters : Provides automatic data filtering to implement some patterns like soft-delete and multi-tenancy.
• Multi Tenancy: It fully supports multi-tenancy, including single database or database per tenant architectures.
• Setting Management : Provides a strong infrastructure to get/change application, tenant and user level settings.
• Unit & Integration Testing: It's built testability in mind. Also provides base classes to simplify unit & integration tests. See this article for more information.

For all features, see documentation.

Startup Templates

Starting a new solution, creating layers, installing nuget packages, creating a simple layout and a menu... all these are also time consuming stuff.

ABP provides pre-built startup templates that makes starting a new solution is much more easier. Templates support SPA (Single-Page Application) and MPA (Multi-Page MVC Applications) architectures. Also, allows us to use different ORMs.

How To Use

ABP is developed on Github and distributed on Nuget . Easiest way of starting with ABP is creating a startup template and following the documentation.