Updating Our Controller to Handle Updates

[MUSIC] 0:00 In this section, we'll be updating the fitness frog web app with the ability to 0:04 update and delete entries. 0:09 Once those features are in place, our web app will be completed. 0:11 In this video, we'll be implementing the ability to update entries The Edit Entry 0:16 page, as you're about to see, is very similar to our Add Entry page. 0:21 Let's see how this will allow us to share code between the two pages. 0:26 Here's our EntriesController class. 0:30 If we navigate to the EditAction method. 0:32 We can see that aside from checking if the ID parameter is null 0:35 it's currently just returning the Edit View. 0:39 Let's add some TODO comments to plan out the changes that we need to make. 0:42 First, we need to update this Action Method to make a call into the repository 0:46 to get the entry for the provided ID parameter value to do 0:51 get the requested entry from the repository. 0:56 But also make sure that an entry was found in if not return a status of not found. 1:03 TODO Return a status of "not found" 1:08 if the entry wasn't found. 1:15 Lastly, we need to pass the entry to our view.TODO Pass that entry into the view. 1:21 We also need to add a corresponding Post action method, just like we did for 1:30 the ad entry page. 1:34 I'll go ahead and stub out that method now. 1:36 Public ActionResult Edit(). 1:38 It'll accept an Entry, and 1:47 return a call to View passing in the entry. 1:50 And also add the HttPost attribute. 1:57 The post version of our EditAction method will look 2:02 very similar to the add post action method. 2:05 Let's scroll up a bit to the Add method and 2:08 split our code editor by clicking on window Split. 2:10 Now, we can scroll the bottom window down to our Edit post action method, okay. 2:15 First, we need to validate the entry. 2:22 Validate the entry and if the entry is valid use the repository to 2:29 update the entry and then redirect the user to the entry's list page. 2:33 If the entry is valid 2:40 Use the repository to update the entry. 2:46 Redirect the user. 2:54 To the entries list page. 2:58 Lastly, we need to populate the activities select list items ViewBag property. 3:00 Populate the activities select 3:09 list items ViewBag property. 3:13 We can remove the split by dragging the divider down to the bottom of the editor. 3:18 Now, let's go back and implement our TODOs. 3:23 To get the entry, we just in to make a call to our repositories get entry method. 3:27 Entry, entry,equals 3:31 entriesRepository.GetEntry(id). 3:36 Don't forget, the ID parameter is a nullable int. 3:44 So, we need to cast it to an int in order to pass it into the get entry method. 3:48 To return a status of not found if the entry wasn't found, 3:55 we just need to check if the entry variable is null. 3:59 And if it is, return a call to the HttpNotFound method. 4:03 If (entry = null) 4:07 return HttpNotFound. 4:12 Remember,, as we saw in an earlier course every controller inherits from the N.B.C. 4:19 controller base class. 4:25 Which provides us with a number of convenience methods for 4:27 returning a variety of action results. 4:30 One of those methods is the HttpNotFound method. 4:33 Our last change to make to this method, is the easiest one to make. 4:38 We just need to pass the entry variable into our View method call. 4:41 Now, on to the Post action method. 4:50 First, we need to validate the entry just like we did in the Add method. 4:53 Here's our server validation rule that ensures the duration field value is 4:59 greater than 0. 5:04 We could just copy and paste this code down into our edit method. 5:05 But a better approach would be to extract this code into its own method. 5:10 Then we could call that method from the Add an EditPostAction methods. 5:14 Visual Studio makes extracting code into a method easy to do. 5:19 Just select these lines of code and 5:23 press control period to open the list of suggested quick actions. 5:25 Then press Enter to select the only item in the list, extract method. 5:29 Visual Studio will prompt us to name the new method. 5:34 Let's name the method ValidateEntry and press enter to complete the refactoring. 5:37 Now, the Add method is calling the validate entry method 5:45 to validate the entry. 5:49 And here's our new ValidateEntry method. 5:50 The method is using the private access modifier, 5:55 which makes it visible to just other members of this class. 5:58 If you'd like to learn more about access modifiers or 6:02 need a refresher, see the teachers notes for links to additional resources. 6:05 Visual Studio created the new method right below our Add method. 6:10 Since this method will be called from other methods in this class, 6:14 we're gonna move this method to the bottom. 6:17 Now, we can update the EditPostAction method with a call to our new 6:22 ValidateEntry method. 6:26 Remember the dry, don't repeat yourself design principle. 6:31 By not repeating our server validation code, we're keeping our code dry. 6:36 Another advantage that we gain by having our service side validation 6:40 in a single method is that if we ever need to change our validation logic 6:44 we only have to update our code in one place. 6:49 Let's tackle our next TODO. 6:52 To check of an entry is valid we need to add an if statement that checks 6:56 if the ModelState IsValid property is true. 7:00 Then, inside of the if statement we can call the repositories update entry method. 7:03 And lastly, return a call to the control or base classes RedirectToAction method 7:09 passing an index for the action method name to redirect to. 7:15 That completes this TODO. 7:19 For our last TODO, 7:24 we need to populate the activities select list items ViewBag propert. 7:25 And just like our service side validation the code that we need 7:30 is already available in the add post action method. 7:33 Actually, this code is already in two places. 7:37 It's also in our Add get action method. 7:40 That reminds me we need to populate the activity select list 7:44 items view big property on every request. 7:48 We forgot to do that on our edit GetAction method. 7:51 Lets add a TODO comment here to remind us about that. 7:55 TODO Populate the activities 7:57 select list items ViewBag property. 8:03 Let's scroll back up to the add GetAction method and 8:10 extract the ActivitesSelectListItems set up code into its own method. 8:13 Select the code, press Ctrl+period, 8:18 press Enter to select the extract method quick action, 8:23 name the method SetUp ActivitiesSelectListItems, 8:27 and press Enter to complete the refactoring. 8:35 And just like we did with the ValidateEntry method, 8:39 let's move the new method to the bottom of the class. 8:42 Now we can update the Add post action method and 8:50 our edit methods to call the new method. 8:53 I'll just copy this line of code and paste it here. 8:56 Here. 9:04 And here. 9:06 And that completes the changes to our controller. 9:09 Let's try building our project by pressing Ctrl+Shift+B. 9:12 Here in the output window we can see that our project was successfully built. 9:17 If you're using GitHub, let's commit our changes. 9:21 Enter a commit message of, Updated the controller 9:26 to support the "Edit Entry" page, and click the Commit All button. 9:31 After the break we'll turn our attention to the View. 9:40