1

00:00:00,710 --> 00:00:07,100

So this time around, what we want to do is to change this menu so that when a user is logged in, this



2

00:00:07,100 --> 00:00:13,340

shows a log out and we want to create the necessary root and handler to actually log a user out of the



3

00:00:13,360 --> 00:00:13,870

system.



4

00:00:13,880 --> 00:00:15,260

And none of that is too difficult.



5

00:00:15,860 --> 00:00:20,870

Now, last lecture, I said I probably use the middleware to accomplish this, and that was wrong.



6

00:00:21,200 --> 00:00:24,050

I'm not going to use the middle where there's a much simpler way to do this.



7

00:00:24,320 --> 00:00:27,260

I'm looking right now at the template data go file.



8

00:00:27,260 --> 00:00:33,680

And if you recall, this struct holds information that is available to every single page of our Web



9

00:00:33,680 --> 00:00:34,040

site.



10

00:00:34,340 --> 00:00:37,700

And all I'm going to do is add a new new member to this or a new field to this.



11

00:00:37,700 --> 00:00:40,970

I'm going to call it is authenticated.



12

00:00:44,900 --> 00:00:47,360

Which I hope I spelled right, it will just be an.



13

00:00:48,830 --> 00:00:53,360

So if this value is greater than zero, then the user will be logged in.



14

00:00:53,630 --> 00:00:56,240

If it's equal to zero, then the user is not logged in.



15

00:00:56,240 --> 00:00:57,880

And that's the simple logic.



16

00:00:58,310 --> 00:01:04,510

So the only thing I need to do is to ensure that I populate that field every request.



17

00:01:04,520 --> 00:01:09,360

And where do I do that while I do that in the render package here, the add default data.



18

00:01:09,980 --> 00:01:13,280

So I need to make a decision here as to whether or not a user is logged in.



19

00:01:13,280 --> 00:01:20,930

And if you recall, when the user is logged in, we set a sessional variable called User Underscore



20

00:01:20,930 --> 00:01:21,350

ID.



21

00:01:21,500 --> 00:01:25,520

So here in our default data, I have access to the request.



22

00:01:25,790 --> 00:01:27,430

That means I can use the session.



23

00:01:27,560 --> 00:01:29,720

So all I have to do is to say something like this.



24

00:01:30,110 --> 00:01:39,800

If app session dot exists and give it the context, are context and look for the key user ID.



25

00:01:39,980 --> 00:01:45,200

If that exists, then populated what is authenticated with one.



26

00:01:45,950 --> 00:01:46,580

And that's it.



27

00:01:46,760 --> 00:01:50,510

Because if it's not there, then the default value for it is authenticate.



28

00:01:50,510 --> 00:01:52,850

It is the default value for an event and that's zero.



29

00:01:53,030 --> 00:01:57,680

So that should give me enough to determine whether or not someone is logged in.



30

00:01:58,910 --> 00:02:04,110

Now, of course, I need to still change this login to log out, and that's not that hard.



31

00:02:04,130 --> 00:02:07,850

Let's go to our base layout and find the log in.



32

00:02:07,850 --> 00:02:08,540

It's right here.



33

00:02:08,720 --> 00:02:10,490

This is the menu item for a login.



34

00:02:10,520 --> 00:02:11,660

I'll just put an if statement here.



35

00:02:12,200 --> 00:02:21,140

So I'll say if equals is authenticated one, then show log out.



36

00:02:21,440 --> 00:02:23,360

So we'll put a space for that.



37

00:02:25,040 --> 00:02:27,010

Else show log in.



38

00:02:28,810 --> 00:02:34,240

And put an end there and format this and then I'll copy this log in.



39

00:02:36,480 --> 00:02:44,400

And paste it up here and change that to user log out a route that doesn't exist yet, but it will momentarily



40

00:02:44,820 --> 00:02:47,310

and change this to log out.



41

00:02:52,140 --> 00:02:57,850

And I guess I didn't get the pointy bracket, so there that should work, so let's try that out.



42

00:02:58,320 --> 00:02:59,220

Let's run this.



43

00:03:01,900 --> 00:03:07,690

Go back to her application, reload this page, log in, shows up like it should, let's put in a valid



44

00:03:07,690 --> 00:03:15,150

login admin at admin dot com password and hopefully when I log in, that will change to log out.



45

00:03:16,750 --> 00:03:17,470

And it does.



46

00:03:18,460 --> 00:03:19,240

So it's log out.



47

00:03:19,240 --> 00:03:23,350

Now, if I click on this, of course, nothing happens because that route doesn't exist yet.



48

00:03:23,350 --> 00:03:26,260

So let's go create the log route, which is really, really easy.



49

00:03:27,070 --> 00:03:28,540

So go back to my reads file.



50

00:03:29,210 --> 00:03:33,940

I'll find the part where I've logged in and right underneath that I'll say mux dot get and I'll make



51

00:03:33,940 --> 00:03:42,460

it a get request user log out and that will go to Handler's repo dot logo, which doesn't exist.



52

00:03:42,790 --> 00:03:44,060

So let's go create that.



53

00:03:44,740 --> 00:03:49,180

So over to our handlers file and at the very bottom, which is where I am right now, I'll create a



54

00:03:49,180 --> 00:03:49,810

new function.



55

00:03:53,390 --> 00:03:57,680

Which I will call funk, and it'll have to have the repository receiver.



56

00:03:59,350 --> 00:04:04,390

And I'll call it logout, and because it's a handler requires a response writer.



57

00:04:06,590 --> 00:04:08,150

And a pointer to a request.



58

00:04:10,830 --> 00:04:12,960

And I just love the user, OK, now how do you do that?



59

00:04:13,150 --> 00:04:18,840

Well, all I really need to do is to make sure that that sessional variable user ID doesn't exist.



60

00:04:19,260 --> 00:04:24,140

But as this application grows, I might be putting more things in the session.



61

00:04:24,150 --> 00:04:27,720

So the simplest thing to do is just to destroy the session.



62

00:04:27,990 --> 00:04:31,950

And we can do that by calling our our session at UT.



63

00:04:32,610 --> 00:04:40,920

So I am dot app, dot session destroyed and all that requires is the context which we can get from our



64

00:04:40,920 --> 00:04:41,580

request.



65

00:04:45,580 --> 00:04:48,440

And then, as I said before, there should be an equal sign there.



66

00:04:48,490 --> 00:04:52,810

This throws an error that I'm not bothering to check for because destroying a session just works.



67

00:04:54,070 --> 00:04:58,030

We also want to regenerate our session Tolkan or renew our session tokens.



68

00:04:58,030 --> 00:04:58,940

So let's do that, too.



69

00:04:58,960 --> 00:05:00,550

It's always good practice to do that.



70

00:05:00,880 --> 00:05:05,740

M dot app, dot session, dot renew, Tolkan.



71

00:05:05,740 --> 00:05:07,450

And that just requires the context.



72

00:05:09,610 --> 00:05:13,090

And then of course we have to take them somewhere, otherwise they're just going to see a white screen.



73

00:05:13,090 --> 00:05:14,650

So we'll take them back to the login screen.



74

00:05:15,610 --> 00:05:27,400

Each redirect w r slash user slash login and some status code, HDTV, the status, the other and that



75

00:05:27,400 --> 00:05:27,930

should work.



76

00:05:27,940 --> 00:05:30,460

But let's give this its comment as we're supposed to do.



77

00:05:32,770 --> 00:05:37,720

Logs a user out, so let's stop our application, start our application.



78

00:05:40,120 --> 00:05:47,440

Go back to this screen, to our application, and let's reload the page, good, so we're not logged



79

00:05:47,440 --> 00:05:56,160

in, so let's log in admin at admin dot com password submit.



80

00:05:56,800 --> 00:05:57,840

I'm now logged in.



81

00:05:58,600 --> 00:05:59,590

Let's try logging out.



82

00:06:00,730 --> 00:06:01,510

And it worked.



83

00:06:01,510 --> 00:06:02,080

Perfect.



84

00:06:02,290 --> 00:06:05,080

Now, one thing you should be aware of, you may have noticed this already.



85

00:06:05,410 --> 00:06:10,000

If I log in admin, admin, dot com password.



86

00:06:12,280 --> 00:06:20,340

I'm logged in right now if I go back and stop my application and start it back up and reload this page,



87

00:06:20,560 --> 00:06:25,570

I will be logged out every time you stop the application because we're just using cookies to store this



88

00:06:25,570 --> 00:06:28,000

information, the login information and track our sessions.



89

00:06:28,630 --> 00:06:33,790

If you stop your application and restart at the sessions are gone, you've lost your session.



90

00:06:33,790 --> 00:06:35,380

And that's that's not a big deal.



91

00:06:35,380 --> 00:06:42,040

When we're working, as we are right now on a local server in production, you may not want to use simple



92

00:06:42,040 --> 00:06:43,480

cookies to store your session.



93

00:06:43,480 --> 00:06:48,370

You may want to use something like Retests or one of the other stores that are available to us.



94

00:06:48,730 --> 00:06:51,880

But that's beyond the scope of what I'm trying to teach you right now.



95

00:06:51,880 --> 00:06:52,870

It's not difficult.



96

00:06:52,870 --> 00:06:59,230

You can read the documentation on Alex Edwards, excession manager, and use retests or some other means



97

00:06:59,230 --> 00:07:00,910

of storing your sessional information.



98

00:07:00,910 --> 00:07:02,830

You can even start in the database if you want to.



99

00:07:03,100 --> 00:07:07,510

And then that sort of thing won't happen because the cookies are not ephemeral.



100

00:07:07,510 --> 00:07:10,990

They don't disappear between restarts of the application.



101

00:07:11,170 --> 00:07:14,110

But for our purposes, this is sufficient for what we're trying to do.



102

00:07:14,560 --> 00:07:18,790

So now we have a means of actually logging a user in and logging user out.



103

00:07:19,030 --> 00:07:25,000

The next step is to actually create some new routes that are only available to users who are logged



104

00:07:25,000 --> 00:07:25,360

in.



105

00:07:25,360 --> 00:07:27,820

And we'll do that in the next lecture.