1
00:00:01,060 --> 00:00:01,750
Enough lecturing.

2
00:00:01,750 --> 00:00:03,340
Time to start writing out some code.

3
00:00:03,400 --> 00:00:04,800
So here's our short term goal.

4
00:00:04,810 --> 00:00:09,040
Here's where we're going to go through the next couple of videos we're gonna create a new sub project

5
00:00:09,220 --> 00:00:11,530
inside of our current project directory.

6
00:00:11,650 --> 00:00:15,370
We're going to make sure that it has types of script support because I want to make sure that we understand

7
00:00:15,370 --> 00:00:18,200
how to work with no not streaming while using typescript.

8
00:00:18,670 --> 00:00:22,780
We're then going to install no net streaming into it and we're going to use it to connect toward that

9
00:00:22,780 --> 00:00:28,280
streaming server then inside this little sub project we're going to make sure that we have two different

10
00:00:28,340 --> 00:00:31,820
NPM scripts essentially two different ways to run our project.

11
00:00:31,820 --> 00:00:34,980
One script is going to try to run some code to emit events.

12
00:00:35,030 --> 00:00:39,680
Internet streaming server and the other script is going to run some code that's going to listen for

13
00:00:39,680 --> 00:00:45,740
events so we'll then have essentially two separate programs where we can emit events or listen for events

14
00:00:47,480 --> 00:00:51,800
last important note that won't throw out is that this program or essentially is two separate programs

15
00:00:52,040 --> 00:00:55,010
are going to be executed from outside of Cuban settings.

16
00:00:55,160 --> 00:00:58,820
So we're not going to worry about creating a deployment or anything like that.

17
00:00:58,820 --> 00:01:03,620
However this is going to present some interesting challenge because we're going to want to connect to

18
00:01:03,620 --> 00:01:07,910
the node that streams server or the net streaming server that is running inside of our Cuban cities

19
00:01:07,940 --> 00:01:08,720
cluster.

20
00:01:08,780 --> 00:01:13,830
So we just need to keep in mind that we need to somehow get access to the Nat streaming server.

21
00:01:14,030 --> 00:01:16,500
So let's get to it to get started.

22
00:01:16,520 --> 00:01:18,090
I can go back over to my terminal.

23
00:01:18,220 --> 00:01:24,620
I'm inside of my route ticketing directory inside of you're going to make a folder called Nat's test

24
00:01:25,640 --> 00:01:30,320
the only reason I'm calling it Dash test is to just make it really clear that this is some little test

25
00:01:30,320 --> 00:01:37,220
project inside of your going to change into that directory generate a package not just on file

26
00:01:40,190 --> 00:01:42,760
will then install a couple of different dependencies.

27
00:01:42,890 --> 00:01:46,120
So in total we're going to get that node and that's streaming thing.

28
00:01:46,160 --> 00:01:51,380
We're also going to get a couple of other dependencies just to run this project using typescript so

29
00:01:51,500 --> 00:02:02,910
npm install we're going to get node Nats streaming T.S. node Dev TypeScript and we're also gonna get

30
00:02:02,940 --> 00:02:10,700
a tight definition file for node J.S. itself at types flash node.

31
00:02:10,950 --> 00:02:15,920
Let's run that it's gonna take just a moment or two to install all that stuff.

32
00:02:15,920 --> 00:02:22,750
So while that's running let's go back over to our Ed and find the new Nats dash test directory inside

33
00:02:22,800 --> 00:02:31,840
they're going to make a new folder called as RC and inside of SLC I'm going to create two files.

34
00:02:32,040 --> 00:02:40,470
I'm going to call one publisher that T.S. and the other listener got to yes so these are going to be

35
00:02:40,470 --> 00:02:43,330
essentially the two separate programs we're going to put together.

36
00:02:43,350 --> 00:02:48,840
One is going to be dedicated to listening for events as it guess that's listener dot to us and the other

37
00:02:48,840 --> 00:02:51,200
is going to be dedicated to publishing events.

38
00:02:51,210 --> 00:02:56,330
Obviously publisher T.S. before worrying about writing out any code inside of here.

39
00:02:56,350 --> 00:03:01,710
Let's write out some different scripts to run each of these two separate files inside a package.

40
00:03:01,730 --> 00:03:02,470
Jason.

41
00:03:02,720 --> 00:03:07,290
I will delete the test script and I'm going to replace it with publish

42
00:03:11,160 --> 00:03:12,660
whenever we run the published commands.

43
00:03:12,660 --> 00:03:16,450
We're going to execute T.S. node Dev.

44
00:03:16,560 --> 00:03:23,210
We're gonna put in a option here of dash dash notify false and then we're going to try to run the SDR

45
00:03:23,220 --> 00:03:31,170
see publisher dot t s file then as a second script we're going to do pretty much the same thing.

46
00:03:31,240 --> 00:03:34,180
It will change the script name to listen.

47
00:03:34,190 --> 00:03:34,790
Still gonna do.

48
00:03:34,820 --> 00:03:35,020
Yes.

49
00:03:35,030 --> 00:03:39,330
No Dev dash dash notify false our.

50
00:03:39,340 --> 00:03:41,260
And this time around listener dot.

51
00:03:41,300 --> 00:03:41,680
Yes

52
00:03:44,560 --> 00:03:45,470
yeah that looks good.

53
00:03:47,520 --> 00:03:50,180
So we've got some root files we've got dependencies.

54
00:03:50,200 --> 00:03:52,810
We've got our scripts before we start to write out some code.

55
00:03:52,810 --> 00:03:55,040
One last little administrative thing we have to do.

56
00:03:55,240 --> 00:03:56,530
We are making use of typescript.

57
00:03:56,560 --> 00:04:01,840
So we really should still create a T S config file inside of here to do so we can't go back over to

58
00:04:01,840 --> 00:04:08,390
our terminal and again inside of our Nat stash test directory a TSC dash dash in it.

59
00:04:08,390 --> 00:04:13,340
And of course this command is assuming that you have typescript globally installed on your system.

60
00:04:13,340 --> 00:04:19,040
So if you get a an error from that you'll need to do an npm install DST type TypeScript and then rerun

61
00:04:19,040 --> 00:04:22,840
TSC dash dash in it OK.

62
00:04:22,890 --> 00:04:25,080
So let's go back over.

63
00:04:25,230 --> 00:04:30,910
We're gonna first start off inside of our publisher dot t yes file inside of you're at the very top.

64
00:04:30,950 --> 00:04:34,200
Let's first import the node Nat streaming library.

65
00:04:34,320 --> 00:04:41,700
So we're going to import nets from node Nats streaming we're then going to use this library to create

66
00:04:41,760 --> 00:04:42,690
a client.

67
00:04:42,810 --> 00:04:47,280
The client is what is going to actually connect to our Nat streaming server and tried to exchange some

68
00:04:47,280 --> 00:04:52,810
information with its will say client is Nats dot connect.

69
00:04:52,810 --> 00:04:57,580
Now quick note here you're going to see inside of just about all the documentation rather than calling

70
00:04:57,580 --> 00:05:00,810
this thing client which is a very reasonable term for it.

71
00:05:00,830 --> 00:05:04,530
Instead a lot of documentation is gonna refer to this as Stan.

72
00:05:04,720 --> 00:05:11,650
So Stan is just kind of a nat streaming server or Nats project little piece of terminology is just what

73
00:05:11,650 --> 00:05:19,890
they like to call a client Nats as you'd kind of guess is simply to me or Stan is just Nats backwards.

74
00:05:20,110 --> 00:05:23,170
So Nats is the library we're kind of a class of sorts.

75
00:05:23,170 --> 00:05:29,110
Stan is an actual instance or a client that we're using to connect to Nat streaming server if you want

76
00:05:29,110 --> 00:05:32,240
to instead called his client because it's a thousand times more clear.

77
00:05:32,290 --> 00:05:33,190
That's totally fine.

78
00:05:33,190 --> 00:05:39,610
But I'm going to stick with the community convention which is to call it Stan it's now inside of connect

79
00:05:39,610 --> 00:05:41,470
right here we're getting an air of course.

80
00:05:41,470 --> 00:05:44,520
So we need to put in a couple of different arguments to this thing.

81
00:05:44,710 --> 00:05:48,010
The first two arguments are gonna put in where it's going to throw in four right now and we'll come

82
00:05:48,010 --> 00:05:50,330
back and discuss why we use these values.

83
00:05:50,330 --> 00:05:52,000
And just a little bit.

84
00:05:52,230 --> 00:05:58,190
The first thing I'm gonna put in is a string of ticketing but a second argument I'm gonna put an ABC

85
00:05:59,310 --> 00:06:05,700
and then finally the last argument I'm gonna put in an object to specify a URL and I'll put it in a

86
00:06:05,700 --> 00:06:11,170
address right here of H TTP and slash slash local post or to do to

87
00:06:14,810 --> 00:06:17,210
then after that we're going to wait.

88
00:06:17,270 --> 00:06:22,850
Or Stan or the client in this case to successfully connect to our Nat streaming server.

89
00:06:22,850 --> 00:06:24,560
So to wait for this thing to actually connect.

90
00:06:24,590 --> 00:06:28,710
Unfortunately again we don't get to make use of that nice async await syntax.

91
00:06:28,730 --> 00:06:32,480
Instead we have to take a primarily event driven approach.

92
00:06:32,480 --> 00:06:38,090
So after the client successfully connects to the Natsumi server is going to emit a Connect event.

93
00:06:38,210 --> 00:06:40,500
So we're going to listen for the Connect event.

94
00:06:40,650 --> 00:06:46,820
I'm going to put in Stan dot on next and then a function as a second argument.

95
00:06:47,390 --> 00:06:52,970
So this function will be executed after the client has successfully connected to the Nat streaming server.

96
00:06:53,060 --> 00:06:57,750
Let's do a console log inside of here just to confirm that that takes place.

97
00:06:58,020 --> 00:07:05,100
So do a console log of publisher connected to that's it.

98
00:07:05,150 --> 00:07:06,440
So this looks good.

99
00:07:06,440 --> 00:07:07,790
Let's save this right here.

100
00:07:07,790 --> 00:07:11,900
If we try to run this code right now we're going to get an error because our net streaming server is

101
00:07:11,900 --> 00:07:18,160
not available on localized or two to two remember answering server is running inside of our communities

102
00:07:18,170 --> 00:07:22,990
cluster and by default we don't have direct access to anything running inside there.

103
00:07:23,030 --> 00:07:23,970
So let's take a pause right here.

104
00:07:23,990 --> 00:07:27,890
We'll come back next video and figure out how we can somehow get access to the Nat streaming server

105
00:07:28,160 --> 00:07:30,550
very easily just for test purposes.