WEBVTT 1 00:00.440 --> 00:01.820 Hi everyone! 2 00:01.820 --> 00:09.050 In this video I will introduce for you the request Lifecycle in NestJS application. 3 00:09.980 --> 00:17.090 And in this video I will not write anything the code in this video, right? 4 00:18.590 --> 00:24.920 Okay, after we watch this video you can feel free to test in this. 5 00:27.080 --> 00:30.290 And what is the request life cycle. 6 00:30.590 --> 00:33.200 And actually the term life cycle right here. 7 00:33.200 --> 00:36.230 Exist in everywhere okay. 8 00:37.400 --> 00:40.520 Anything in the world will have a life cycle. 9 00:40.550 --> 00:41.210 Right. 10 00:41.540 --> 00:43.910 And the NestJS is not exception. 11 00:43.940 --> 00:45.800 We have a request lifecycle. 12 00:45.920 --> 00:54.050 If you want to look up the document you can go to the FAQ right here and click on Request Life 13 00:54.080 --> 00:54.710 Cycle. 14 00:56.000 --> 00:57.830 Now let me explain for you. 15 00:58.550 --> 01:06.130 Let me reminder for you in my previous video. I think in the first section, we already know 16 01:06.340 --> 01:07.870 the life cycle. 17 01:08.050 --> 01:13.300 When we have a request, it will accept us using the middleware first. 18 01:13.330 --> 01:14.020 Right? 19 01:15.010 --> 01:15.730 Middleware. 20 01:16.390 --> 01:19.660 And after middleware, it will trigger the Guard 21 01:21.850 --> 01:23.320 Right after Guard. 22 01:23.350 --> 01:26.260 It will give the interceptor. 23 01:26.410 --> 01:27.100 Right. 24 01:27.670 --> 01:33.070 So this is the lifecycle of the request and response. 25 01:34.420 --> 01:40.690 But what is, for example, in the guard we have a global guard. 26 01:40.960 --> 01:47.380 We have a so many concept related to global guard okay or the interceptor. 27 01:47.380 --> 01:50.260 It also have a global interceptor right. 28 01:51.340 --> 01:59.410 And we have a something called controller level of the guard or the interceptor. 29 01:59.620 --> 02:02.170 And we have a method level. 30 02:04.980 --> 02:05.550 Okay. 31 02:05.550 --> 02:07.620 And also we have a global. 32 02:09.630 --> 02:12.090 So how it can be excuted. 33 02:12.120 --> 02:15.540 For example with guard we have a global guard. 34 02:15.780 --> 02:19.590 We have something called global controller. 35 02:20.160 --> 02:23.490 Sorry the guard controller. 36 02:23.580 --> 02:25.860 And we have a guard in the methods. 37 02:26.580 --> 02:31.710 Now let me show you what it means inside the overview right here. 38 02:32.490 --> 02:38.850 For example, if I go out into the interceptor now we will scroll down a little bit. 39 02:39.660 --> 02:43.200 We have an interceptor right and right here. 40 02:43.200 --> 02:51.180 It will use it into the class, it means this is a class level interceptor okay. 41 02:51.450 --> 02:54.600 And we can actually do that in the methods. 42 02:56.340 --> 02:59.100 Or we can use the global right here. 43 02:59.130 --> 03:02.340 Now you can see this is a global interceptor. 44 03:02.340 --> 03:10.280 And it is also available interceptor you can see and when we do the project, we will see this approach. 45 03:10.850 --> 03:13.070 Don't worry about what it means right now. 46 03:13.850 --> 03:15.440 You will understand later. 47 03:16.340 --> 03:16.970 Okay. 48 03:17.000 --> 03:23.960 And actually we can also use that in the in the method level right here. 49 03:23.990 --> 03:27.500 Let me show you for example right here. 50 03:29.420 --> 03:32.960 Let me open the the post controller here. 51 03:33.710 --> 03:34.070 Okay. 52 03:34.250 --> 03:36.710 Here will be the class level. 53 03:37.460 --> 03:38.450 Class level. 54 03:40.670 --> 03:48.440 And if I go in the @POST right here, it means this is the method level interceptor. 55 03:48.830 --> 03:49.400 Okay. 56 03:49.790 --> 03:54.620 And if we use something like this, I will call. 57 03:54.620 --> 03:55.640 This will be the. 58 04:01.640 --> 04:03.110 Something like this, I'll call 59 04:03.110 --> 04:05.330 This will be the global interceptor. 60 04:05.330 --> 04:07.340 And how it can be excuted. 61 04:07.880 --> 04:08.450 Okay. 62 04:08.570 --> 04:11.740 That's the concept of request lifecyle 63 04:11.740 --> 04:12.460 Read more about that 64 04:13.360 --> 04:20.890 If we scroll down a little bit right here, now, you can see, you can read a summary right here, 65 04:20.920 --> 04:23.140 or you can read details. 66 04:24.940 --> 04:29.380 You can read details for example like that, the middleware excute. 67 04:29.680 --> 04:32.200 Uh, right here. 68 04:32.230 --> 04:32.710 Right. 69 04:33.610 --> 04:38.590 You can see, and after that we will go to the guard. 70 04:39.040 --> 04:42.940 The guard will be start with global guard and then the controller guard. 71 04:42.940 --> 04:46.690 And finally the route guard. This is a "route guard" 72 04:48.160 --> 04:50.110 Or you can see the method level. 73 04:52.300 --> 05:03.040 Now you can see, if we use something like this if we if we use something like 2 guards here and also 74 05:03.040 --> 05:03.880 guard here. 75 05:03.880 --> 05:07.420 What it's mean, the guard one will be executed first. 76 05:10.240 --> 05:12.780 And after that it will run the guard 2 77 05:13.320 --> 05:18.060 And after that we will go to the useGuard in method level 78 05:21.900 --> 05:25.590 Okay, you can read more about them right here. 79 05:29.160 --> 05:35.790 And interceptor is it will be the same. Let meread more about that. 80 05:36.240 --> 05:41.130 When we have a incoming request it will accept by middleware okay. 81 05:41.130 --> 05:47.520 And it will back to the global middleware and also the module middleware. 82 05:48.660 --> 05:50.880 And the guard is similar. 83 05:50.910 --> 06:00.660 Firstly we will the global guard and the second will be controller guard and route guard 84 06:01.320 --> 06:01.920 Okay. 85 06:02.040 --> 06:04.200 Interceptor will be the same right. 86 06:04.230 --> 06:05.760 You can see it will be the same. 87 06:05.760 --> 06:07.050 And also the pipes. 88 06:08.370 --> 06:16.100 And we have so many things after each run, the some steps, it will come back to the controller 89 06:16.250 --> 06:25.820 and service and post interceptor because the interceptor it will have a two way, right? 90 06:26.030 --> 06:27.380 This is the interceptor. 91 06:27.740 --> 06:31.940 And when we respond, it also have interceptor, right? 92 06:32.660 --> 06:35.690 For that reason, it will trigger interceptor in this step. 93 06:36.860 --> 06:39.350 And we also have exception. 94 06:39.530 --> 06:43.130 And after that, the finally will be the response. 95 06:43.160 --> 06:43.670 Right. 96 06:44.240 --> 06:52.190 We can see the interceptor execute before the server response. 97 06:52.220 --> 06:52.520 Right. 98 06:52.550 --> 06:59.780 You can see okay, that's it. That's the concept of request life cycle. 99 06:59.810 --> 07:04.280 You can read more about them in the topics right here. 100 07:04.310 --> 07:07.760 But I think this very enough for you right now. 101 07:09.470 --> 07:13.190 So that's it for the video. 102 07:14.240 --> 07:16.100 I will see you in the next one.