uoiboy/cheesemvc-1

LC101 Unit3 CheeseMVC

CheeseMVC

Class 13 Prep

Class 13 Prep

NOTE: Again, I augment our existing CheeseMVC app, and do not follow the starter code exactly. See my comments for Class 12 Prep below.

Class 12 Prep

Class 12 Prep

NOTE: The code for class 12 prep does not follow the video tutorials exactly. It is not based on the Entity Framework starter project, but is rather a natural progression from previous CheeseMVC lessons. The chief differences are:

• there is no CategoryController, all category routes are in CheeseController
• there is no user interface for creating a new CheeseCategory, this must be done manually through SQL Server Object Explorer
• The view models may contain properties that are named differently (for example, NewCheeseViewModel.SelectedCheeseCategoryID instead of NewCheeseViewModel.CategoryID)
• there are several more migrations because I changed the Cheese class incrementally

Class 9

Class 9 Prep

NOTE: I did not start/end with the Git branches specified in the prep work description. All of my code modifications may be found in the class-9-prep branch.

Class 8

Class 8 Prep

NOTE: I did not start/end with the Git branches specified in the prep work description. All of my code modifications may be found in the class-8-prep branch.

Class 5

Class 5 Prep

Class 4

Class 4 Prep

Intro to ASP.NET Core MVC: Views (Part 1)

• controller => C# class
• view => .cshtml file

By default, "views" (.cshtml files) are located:

• PROJECT/Views/[ControllerName]/[ActionName].cshtml
• PROJECT/Views/Shared/[ActionName].cshtml

Razor templates (.cshtml) are similar to Jinja templates in Python in that they can contain both HTML markup and view logic.

ViewData is a specizlized Dictionary that acts as a "bucket" of data passed into the view.

To share a view across different controllers, put it in /Views/Shared.

C# code can be added to a view by prefixing it with an @ symbol.

A default layout can be applied to all views by adding the file: /Views/Shared/_Layout.cshtml.

Changes to views do not require a server restart ("hot deployment").

Intro to ASP.NET Core MVC: Views (Part 2)

Code blocks can be added to Razor views by preceeding them with the @ symbol:

<ul>
    @foreach (string cheese in cheeses)
    {
        <li>@cheese</li>
    }
</ul>

It is generally not a good idea to create data in view files!

There are multiple ways to pass data to a view.

ViewBag is a "dynamic" object that can be assigned properties of any type that contain data for the view. This is very similar to, but not the same, as ViewData. (See: ViewModel vs ViewData vs ViewBag vs TempData vs Session in MVC)

Links (<a> tags) can use asp-* attributes to generate href values:

<a asp-controller="Cheese" asp-action="Add">Add Cheese</a>

Static class properties can make data available to any instance of a class:

public class CheeseController : Controller
{
    // available to *all* instances of CheeseController;
    // all instances *share* this list
    private static List<string> cheeses = new List<string>();

    // created per-instance; each instance gets its own list
    private List<string> moreCheeses = new List<string>();
}

The Controller.Redirect() method returns a RedirectResult, which can be returned from a controller action method to take the user to some other route.

Studio

Routing parameters can be added to anchors using special MVC helper attributes.

In the controller:

[Route("/cheese/remove/{cheeseName}")]
[HttpGet]
public IActionResult RemoveSingleCheese(string cheeseName)
{
    // ... remove the cheese
    return Redirect("/cheese");
}

In the view:

<a asp-controller="Cheese"
   asp-action="RemoveSingleCheese"
   asp-route-cheeseName="@cheeseName">delete</a>

Inputs can be submitted as an array of values to an action method.

In the controller:

[Route("/cheese/remove")]
[HttpPost]
public IActionResult RemoveManyCheeses(string[] selectedCheeses)
{
    // ... remove the cheeses
    return Redirect("/cheese");
}

In the view:

<form method="post">
<ul>
    @foreach (KeyValuePair<string, string> cheese in ViewBag.cheeses)
    {
        <li>
            <input name="selectedCheeses[]" type="checkbox" value="@cheese.Key" />
            <label>@cheese.Key</label>
        </li>
    }
</ul>
<input type="submit" valu="Delete Cheeses"/>
</form>