Skip to content

Latest commit

 

History

History
84 lines (68 loc) · 5.54 KB

PostCategories.md

File metadata and controls

84 lines (68 loc) · 5.54 KB
Raw

My Blog Sample

(Italian translate)

Add categories to Posts [database, backend, frontend]

Jim wants to create logical categories to collect the Posts. He would like the Posts to be linked to a category, for now he doesn't mind being able to link them to more than one category, only one is enough.

Tom suggests inserting a new table for the categories and adding a reference to the category in the Post table.

Implementation specifications

Database

  • Create a table called Categories with the following columns:
      • Id * [int, primary key],
      • Name * [string],
      • Description * [string],
      • CreateDate * [datetime]
  • Create new column in Posts table named CategoryId, which will be foreign key on category table id.

Backend

Domain Project
  • Add an ICategory.cs interface in the /Interfaces/Models folder, use the IPost.cs as a trace, copy the code and adapt it, but add a property to hold the category posts:
public List<Post> Posts { get; set; }
  • Add an ICategoriesRepository.cs interface in the /Interfaces/Repositories folder, use the IPostsRepository.cs as a trace, copy the code and adapt it
  • Add an ICategoriesService.cs interface in the /Interfaces/Services folder, use the IPostsService.cs as a trace, copy the code and adapt it
  • Add a Category.cs class in the /Models folder, use the Post.cs as a trace, copy the code and adapt it
  • Add a property CategoryId in interface /Interfaces/Models/IPost.cs and in class /Models/Post.cs
UnitTest DAL project (optional, but highly recommended)
  • Add a Category.cs class in the /Models folder, use the Post.cs class as a trace, copy the code and adapt it
  • Add a CategoriesHelper.cs class in the /Helpers folder, use the PostsHelper.cs class as a trace, copy the code and adapt it
  • Add a CategoriesRepositoryTest.cs class in the /Repositories folder, use the PostsRepositoryTest.cs class as a trace, copy the code and adapt it. (In the test that verifies the retrieve of a category you will also have to insert the posts in the InMemory database, otherwise you will receive an error).
// insert post because of InMemory DB must have table Posts
var mockPosts = PostsHelper.GetDefaultMockData();
db.Insert<Post>(mockPosts);
Be careful, in the CategoriesRepositoryTest.cs class use the Category class you created in this project, not the Domain project one. This is an exception due to the InMemory database not recognizing the table name correctly, with this hack you can pass the table name through the Post class attribute, or in your implementation Category (Tom is still working to solve this case correctly).
[Alias("Posts")]
Be careful, the test project doesn't compile because of there are no class in DAL Project. It's ok, in TDD practice you write before the test and then you write code for use it.
DAL Project

Add CategoriesRepository.cs class in /Repositories folder, use PostsRepository.cs class as trace, copy the code and adapt it, but remember to retrieve all posts of the category in the property:

public List<Post> Posts { get; set; }
Progetto UnitTest BL (opzionale, ma vivamente consigliato)
  • Add CategoriesHelper.cs class in /Helpers folder, use PostsHelper.cs class as trace, copy the code and adapt it
  • Add CategoriesServiceTest.cs class in /Services folder, use PostsServiceTest.cs class as trace, copy the code and adapt it
BL Project
  • Add the CategoriesService.cs class in the /Services folder, use the PostsService.cs class as a trace, copy the code and adapt it

Web Project

  • Add the Categories action in the HomeController controller, use the Index action as a trace, copy the code and adapt it
  • Add the Category({id}) action in the HomeController controller, use the Post({id}) action as a trace, copy the code and adapt it
  • Add the Categories view in the Views/Home folder, use the Index view as a trace, copy the code and adapt it
  • Add the Category view in the Views/Home folder, use the Post view as a trace, copy the code and adapt it, but remember that you will also have to display the list of posts contained in the category, for this you see the foreach in the Index view
  • Add a link to Categories page in Views/Shared/_Layout.cshtml, you can copy and past the link Home and adapt it
<a href="@Url.Action("Categories", "Home")" data-rb-event-key="about" class="nav-link">Categories</a>
  • In file Startup.cs add code to handle dependence injection for the new interfaces and classes, inside the function ConfigureServices:
services.AddScoped<ICategory, Category>();
services.AddScoped<ICategoriesRepository, CategoriesRepository>();
services.AddScoped<ICategoriesService, CategoriesService>();

Integration Test Web Project

  • Add a test like HomeControllerTest.should_retrieve_all_posts to verify that the categories page responds correctly
  • Add a test like HomeControllerTest.should_retrieve_post_by_id to verify that the category page responds correctly when requesting an existing id
  • Add a test like HomeControllerTest.should_retrieve_no_one_post to verify that the category page responds correctly when requesting a non-existent id

See the repository with the implementation (!!! contains spoilers)

Return to main page