Added item for page 655

docs/errata/README.md

@@ -4,6 +4,6 @@ If you find any mistakes in the seventh edition, *C# 11 and .NET 7 - Modern Cros
 
 [**Errata** (27 items)](errata.md): Typos, tool user interface changes, or mistakes in code that would cause a compilation error that prevents a successful build.
 
-[**Improvements** (4 items)](improvements.md): Changes to text or code that would improve the content. These are optional.
+[**Improvements** (5 items)](improvements.md): Changes to text or code that would improve the content. These are optional.
 
 All errata and improvements will be included in the 8th edition planned for publishing in November 2023. To be included they must be submitted by mid-September 2023.

docs/errata/improvements.md

@@ -1,4 +1,4 @@
-**Improvements** (4 items)
+**Improvements** (5 items)
 
 If you have suggestions for improvements, then please [raise an issue in this repository](https://github.com/markjprice/cs11dotnet7/issues) or email me at markjprice (at) gmail.com.
 
@@ -6,6 +6,7 @@ If you have suggestions for improvements, then please [raise an issue in this re
 - [Page 153 - Writing a function that returns a value](#page-153---writing-a-function-that-returns-a-value)
 - [Page 179 - Reviewing project packages](#page-179---reviewing-project-packages)
 - [Page 453 - Scaffolding models using an existing database](#page-453---scaffolding-models-using-an-existing-database)
+- [Page 655 - Exercise 14.2 – Practice implementing MVC by implementing a category detail page](#page-655---exercise-142--practice-implementing-mvc-by-implementing-a-category-detail-page)
 
 # Page 128 - Rounding numbers
 
@@ -69,3 +70,65 @@ For convenience, here is the same command as a single line to make it easier to
 ```
 dotnet ef dbcontext scaffold "Filename=Northwind.db" Microsoft.EntityFrameworkCore.Sqlite --table Categories --table Products --output-dir AutoGenModels --namespace WorkingWithEFCore.AutoGen --data-annotations --context Northwind
 ```
+
+# Page 655 - Exercise 14.2 – Practice implementing MVC by implementing a category detail page
+
+Earlier in the chapter, and in Exercise 14.2, the link generated for a category detail page looks like this:
+```
+https://localhost:5001/category/1
+```
+
+Although it is possible to configure a route to respond to that format of link, it would be easier if the link used the following format:
+```
+https://localhost:5001/home/categorydetail/1
+```
+
+In `Index.cshtml`, change how the links are generated to match the improved format, as shown in the following markup:
+```xml
+<a class="btn btn-primary"
+  href="/home/categorydetail/@Model.Categories[c].CategoryId">View</a>
+```
+
+This would then allow you to add an action method to the `HomeController` class as shown in the following code:
+```cs
+public async Task<IActionResult> CategoryDetail(int? id)
+{
+  if (!id.HasValue)
+  {
+    return BadRequest("You must pass a category ID in the route, for example, /Home/CategoryDetail/6");
+  }
+
+  Category? model = await db.Categories.Include(p => p.Products)
+    .SingleOrDefaultAsync(p => p.CategoryId == id);
+
+  if (model is null)
+  {
+    return NotFound($"CategoryId {id} not found.");
+  }
+
+  return View(model); // pass model to view and then return result
+}
+```
+
+And create a view that matches the name `CategoryDetail.cshtml`, as shown in the following markup:
+```xml
+@model Packt.Shared.Category 
+@{
+  ViewData["Title"] = "Category Detail - " + Model.CategoryName;
+}
+<h2>Category Detail</h2>
+<div>
+  <dl class="dl-horizontal">
+    <dt>Category Id</dt>
+    <dd>@Model.CategoryId</dd>
+    <dt>Product Name</dt>
+    <dd>@Model.CategoryName</dd>
+    <dt>Products</dt>
+    <dd>@Model.Products.Count</dd>
+    <dt>Description</dt>
+    <dd>@Model.Description</dd>
+  </dl>
+</div>
+```
+
+> Note: You could also use the simpler link format `https://localhost:5001/home/category/1` but then both the action method and the view filename must be just `Category` instead of `CategoryDetail`.