Using TempData

Currently, after we add, update, or 0:00 delete an entry we're redirected to the entries list page, but 0:02 there's no visual indication or message that the action successfully completed. 0:06 Let's see how we can use TempData to resolve this issue. 0:11 TempData can be used to pass data from a controller to a view. 0:15 On its own, that's not that unique. 0:19 ViewBag as we've seen in this course and 0:22 ViewData as we'll see in future Treehouse content, can both be used in the same way. 0:24 What makes TempData unique is that while ViewBag and viewdata must be used within 0:30 the same request TempData survives to the next request and then expires. 0:34 This allows us to set a TempData value on a request, redirect the user, and 0:40 display that value as part of the new request. 0:45 Let's see an example of TempData in action by updating the add entry page 0:48 to display a confirmation message on the entries list page. 0:52 Go ahead and stop the app and open our controller. 0:56 In the controllers add post action method, we need to add a line of code to set our 1:06 TempData value right before the call to the redirect to action method. 1:11 TempData["Message"] = and 1:21 then our message. 1:26 Your entry was successfully added. 1:29 Now open the view for the entries list page. 1:36 The index CSHTML file in the Views Entries folder. 1:39 We need to add an if statement to this view to check if the few data message key 1:44 has a value. 1:48 And if it does render it to the view @if ( 1:49 TempData [ "Message"] != null) then 1:54 a div containing @TempData ["Message"]. 2:00 Let's test our changes by pressing F5 to run the app. 2:06 Browse to the ad entry page. 2:16 Provide values for the entry and duration fields and save the form. 2:19 And here's our confirmation message at the top of the entries list page. 2:24 If we refresh the page we can see that the message will disappear demonstrating 2:29 that the temp data message value didn't survive past the next request. 2:34 Go ahead and stop the app so 2:39 we can add two more confirmation messages to our controller. 2:40 One when users update an entry and one when they delete an entry. 2:43 Starting with the edit post action method, let's set the temp data message value 2:48 right before the call to the redirect to action method. 2:52 TempData ["Message"] = "Your 3:00 entry was successfully updated!" and 3:05 then in the delete post action method. 3:10 TempData ["Message"] = "Your 3:22 entry was successfully deleted!". 3:26 Now let's make one more change to our view. 3:31 When our project's designer heard that we were planning on adding 3:38 confirmation messages to the entry's list page, they sent me the following HTML. 3:41 If you're following along, you could find this markup in the teacher's notes. 3:46 I'll select and copy this markup to the clipboard. 3:50 Switch back to Visual Studio and paste from the clipboard into our view 3:53 replacing the contents of our if statement. 3:59 Don't forget to replace the static message text here with our TempData message value. 4:02 @TempData ["Message"]. 4:07 The HTML that our designer provided to us is based on Bootstrap dismissible alerts. 4:14 For more information about that Bootstrap feature see the teacher's notes. 4:20 Now let's run and test our app again. 4:23 Browse to the add entry page provide the required values and save the form. 4:27 And here's a confirmation message with its improved style. 4:34 Notice that we can click the X on the right to dismiss the message. 4:39 Now let's test updating and deleting an entry. 4:44 First updating. 4:47 Click on the first entries Edit button. 4:48 Change the activity field value, then save the form. 4:52 And here's our confirmation message that the entry was successfully updated. 4:58 Now deleting. 5:02 Click the Delete button on our new entry and confirm the deletion. 5:04 And here's our confirmation message that the entry was successfully deleted. 5:10 Everything seems to work as expected. 5:15 Go ahead and stop the app. 5:18 If you're using GitHub, let's commit our changes. 5:21 Enter a commit message of Added confirmation messages and 5:28 click the Commit All button. 5:33 Let's also sync with the remote server. 5:38 Navigate to the synchronization panel, and click the Push link. 5:40 After the break, we'll review the section and wrap up the course. 5:46