# 7.1: Validation Messages

The code in this section adds success/failure messages for validation of note creation.

## Update the Create \[HttpPost] Method

1. Still in **ElevenNote.Web -> Controllers -> NoteController**
2. Change the `Create` \[Post] method to match this:

   ```csharp
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create(NoteCreate model)
        {
            if (!ModelState.IsValid) return View(model);

            var service = CreateNoteService();

            if (service.CreateNote(model))
            {
                return RedirectToAction("Index");
            };

            return View(model);
        }
   ```

## ViewBag vs ValidationSummary

1. Go to **ElevenNote.Web -> Views -> Note**
2. Open `Create.cshtml`
3. Notice the `ValidationSummary`
4. `ViewBag` is a way that communication could go to the view
5. Instead we will use `ValidationSummary`

## Add Model Error Message

1. Go back to **ElevenNote.Web -> Controllers -> NoteController**
2. Comment out the following code and add `ModelState.AddModelError...`, this way you can run the app and see the error message.

   ```csharp
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create(NoteCreate model)
        {
            if (!ModelState.IsValid) return View(model);

            //var service = CreateNoteService();

            //if (service.CreateNote(model))
            //{
            //    return RedirectToAction("Index");
            //};

            ModelState.AddModelError("", "Note could not be created.");

            return View(model);
        }
   ```
3. Run the app and try to create a note. You should see the error message:

   ![Error](/files/-LAxNDKTfcUeHiE_2Zw7)
4. Let's stop the app so that we can fix this.

## Add Success Message

1. Un-comment out the lines from before
2. Inside the `NoteController` conditional that indicates the save was successful, add `ViewBag.SaveResult = "Your note was created.";`
3. Your code should look like this:

   ```csharp
        [HttpPost]
        [ValidateAntiForgeryToken]
        public ActionResult Create(NoteCreate model)
        {
            if (!ModelState.IsValid) return View(model);            

            var service = CreateNoteService();

            if (service.CreateNote(model))
            {
                ViewBag.SaveResult = "Your note was created.";
                return RedirectToAction("Index");
            };

            ModelState.AddModelError("", "Note could not be created.");

            return View(model);
        }
   ```

## Add a Bootstrap Error Message in the View

1. Click on the `Index()` method and type `CTRL M G`, this should take you to the `Index.cshtml` file
2. Or, go to **ElevenNote.Web -> Views -> Note -> Index.cshtml**
3. Add this `<div>` between the `<p>` and the `<table>`

   ```markup
    <p>
        @Html.ActionLink("Create New", "Create")
    </p>
       <div class="alert alert-success fade in" role="alert">
            @ViewBag.SaveResult
            <button type="button" class="close" data-dismiss="alert">
                <span>&times;</span>
            </button>
        </div>
   ```
4. This uses a Bootstrap component, click [here](https://getbootstrap.com/docs/3.3/components/#alerts) to look at the docs.
5. The success message does not appear because of the `RedirectToAction`
6. RedirectToAction create ViewBag.Result to the following:
7. Back in the `NoteController.cs` file, change `ViewBag` to `TempData`

   ```csharp
         var service = CreateNoteService();

        if (service.CreateNote(model))
        {
            TempData["SaveResult"] = "Your note was created.";
            return RedirectToAction("Index");
        };
   ```
8. `TempData` removes information after it's accessed&#x20;
9. Go back to the `Index.cshtml` file
10. wrap your `<div class="alert...>` in the following conditional:

    ```markup
    <p>
        @Html.ActionLink("Create New", "Create")
    </p>

    @if(TempData.ContainsKey("SaveResult"))
    {
        <div class="alert alert-success fade in" role="alert">

            <button type="button" class="close" data-dismiss="alert">
                <span>&times;</span>
            </button>
            @TempData["SaveResult"]
        </div>
    }
    ```
11. `.ContainsKey` checks to see if that key is in the dictionary, but will not remove it.
12. Run the app, you should see this message when you create a note:

    ![Success Message](/files/-LAxNDxc-OFNWPwoR-cJ)
13. ![Git](/files/-LAwyxUd0dcYSLXYb-5s)

[Next,](/dotnet-201-elevennote/elevennote-parts-1-11/part-8-notedetail/8.0-notedetail.md) we'll work on the Note detail.


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