From bcb8f59e40c0de81e7ed6c70c0be69d9ef80b1ee Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Halil=20=C4=B0brahim=20Kalkan?= <hi_kalkan@yahoo.com>
Date: Tue, 10 Apr 2018 18:00:56 +0300
Subject: [PATCH] Creating module development best practices document.

---
 docs/Module-Development-Best-Practices.md     | 54 +++++++++++++++++++
 .../Repositories/MongoDB/MongoDbRepository.cs |  2 +
 2 files changed, 56 insertions(+)
 create mode 100644 docs/Module-Development-Best-Practices.md

diff --git a/docs/Module-Development-Best-Practices.md b/docs/Module-Development-Best-Practices.md
new file mode 100644
index 0000000000..097b00dee1
--- /dev/null
+++ b/docs/Module-Development-Best-Practices.md
@@ -0,0 +1,54 @@
+## Module Development
+
+### Introduction
+
+This document describes the best practices for who want to develop modules that satisfies the following specifications:
+
+* Develop the module that applies the **Domain Driven Design** patterns & best practices.
+* Develop the module as DBMS and **ORM independent**.
+* Develop the module that can be used as a remote service / **microservice** as well as can be integrated to a **monolithic** application.
+
+### Data Access Layer
+
+The module should be completely independent of any DBMS and and ORM.
+
+- **Do not** use `IQueryable<TEntity>` features in the application code (domain, application... layers) except the data access layer.
+- **Do** create separated packages (projects/assemblies/libraries) for each ORM integration (like *Company.Module.EntityFrameworkCore* and *Company.Module.MongoDB*).
+- **Do** always use the specifically created repository interface (like `IIdentityUserRepository`) from the application code (as developed specified below). **Do not** use generic repository interfaces (like `IRepository<IdentityUser, Guid>`).
+
+#### Repositories
+
+* **Do** define a repository interface (and create its corresponding implementations) for each aggregate root.
+
+For the example aggregate root:
+
+````C#
+public class IdentityUser : AggregateRoot<Guid>
+{
+    //...
+}
+````
+
+Define the repository interface as below:
+
+````C#
+public interface IIdentityUserRepository : IBasicRepository<IdentityUser, Guid>
+{
+    //...
+}
+````
+
+* **Do** define repository interfaces in the **domain layer**.
+* **Do not** inherit the repository interface from `IRepository` interfaces. Because it inherits `IQueryable` and the repository should not expose `IQueryable` to the application.
+* **Do** inherit the repository interface from `IBasicRepository<TEntity, TKey>` (as normally) or a lower-featured interface, like `IReadOnlyRepository<TEntity, TKey>` (if it's needed).
+* **Do not** define repositories for entities those are **not aggregate roots**.
+* **Do** define all repository methods as **asynchronous**.
+* **Do** add a `cancellationToken` parameter to every method of the repository. 
+* **Do** create a **synchronous extension** method for each asynchronous repository method.
+* ...
+
+#### Integrations
+
+##### Entity Framework Core
+
+##### MongoDB
\ No newline at end of file
diff --git a/src/Volo.Abp.MongoDB/Volo/Abp/Domain/Repositories/MongoDB/MongoDbRepository.cs b/src/Volo.Abp.MongoDB/Volo/Abp/Domain/Repositories/MongoDB/MongoDbRepository.cs
index 2385ab150c..461b24460c 100644
--- a/src/Volo.Abp.MongoDB/Volo/Abp/Domain/Repositories/MongoDB/MongoDbRepository.cs
+++ b/src/Volo.Abp.MongoDB/Volo/Abp/Domain/Repositories/MongoDB/MongoDbRepository.cs
@@ -12,6 +12,8 @@ using Volo.Abp.MultiTenancy;
 
 namespace Volo.Abp.Domain.Repositories.MongoDB
 {
+    //TODO: Use GetCancellationToken() method!
+
     public class MongoDbRepository<TMongoDbContext, TEntity> : RepositoryBase<TEntity>, IMongoDbRepository<TEntity>
         where TMongoDbContext : IAbpMongoDbContext
         where TEntity : class, IEntity