WEBVTT 00:05.200 --> 00:07.400 Pay everyone welcome back. 00:07.400 --> 00:14.390 So in the last video we talked about Jason what Jason is in how we can use it as a format to send data 00:14.420 --> 00:16.500 from one server to the other. 00:16.520 --> 00:22.040 So in this video we're going to go back into eight to talk about HTB are we going to be talking about 00:22.040 --> 00:27.430 in much more detail so that we understand what we're supposed to do when we're developing a server. 00:27.860 --> 00:32.310 Ok so let's get started again with the same example that we always do. 00:32.450 --> 00:40.370 So let's say that you have your browser over here that's your browser and then on here we have Google 00:40.370 --> 00:49.950 servers so called servers and on it is how the the Web site google.com is hosted. 00:50.450 --> 00:56.580 OK so let's say you write google.com in your browser and again your browser goes to your ISP. 00:56.600 --> 01:02.730 You know does a DNS look up all that stuff and finally gets the IP for your Google server. 01:02.860 --> 01:03.950 And that's what we care about. 01:03.950 --> 01:06.620 We don't really care about the process in here. 01:06.770 --> 01:14.820 Now once we have the IP then your browser wants to initiate a request to your Google to Google the company. 01:15.200 --> 01:18.580 So our request should have a specific format. 01:18.720 --> 01:19.260 OK. 01:19.520 --> 01:23.240 The last time we were just saying well required we just send the request direct. 01:23.240 --> 01:28.040 So in this video we're going to be explaining how the request and the response should look like. 01:28.280 --> 01:37.100 So whether the request request can be should star in the beginning to identify what type of request 01:37.340 --> 01:37.800 this is. 01:37.910 --> 01:39.420 What message are you using. 01:39.680 --> 01:45.500 And there are so many different methods that you can use during a request for this video and really 01:45.500 --> 01:49.210 for most of the development we only focus on two of them. 01:49.390 --> 01:54.700 So we have to get to request and we have a POST request. 01:54.830 --> 01:58.250 Now you might you might be wondering OK what's it got what's pose. 01:58.250 --> 02:04.910 And actually we've been using so far all along throughout the videos we've actually been using get now 02:04.940 --> 02:05.260 what. 02:05.310 --> 02:10.960 Get means is that it simply requests from the server to get right. 02:10.970 --> 02:16.380 And the name suggests to get a specific resource from their server. 02:16.820 --> 02:22.880 And what what what kind of a resource is identified by what's after. 02:23.060 --> 02:36.470 So if I say get from Google that can and then right after it slash index ASTM then I'm requesting from 02:36.470 --> 02:38.840 Google dot com to give me their resource. 02:38.870 --> 02:43.450 Each DMA I'm requesting to get that resource from there. 02:43.880 --> 02:51.470 So in other words again it is just simply asking the server Hey sir I need some resource whether it's 02:51.670 --> 03:01.070 page whether it's you know some kind of resource and that and this and this place with that name then 03:01.070 --> 03:03.020 I simply use get to get it. 03:03.020 --> 03:05.440 Now we've been using this so far we always have. 03:05.460 --> 03:14.180 If you feel actually if we actually go back to our coding example here and at the root by Slash by and 03:14.180 --> 03:19.060 then if we actually go to the answer here we'll see here that one. 03:19.100 --> 03:21.500 So let's let's run flask here. 03:21.890 --> 03:22.540 Okay. 03:22.820 --> 03:30.770 And then if we go to here 2 2 to localhost slash by the way click enter and then we get the response 03:30.770 --> 03:31.070 back. 03:31.070 --> 03:39.870 You'll notice here that it says Get So we got gotten a request and slash by. 03:40.190 --> 03:46.110 So we get request and at the end point slash right. 03:46.490 --> 03:49.480 And it's using the protocol HTP. 03:49.610 --> 03:57.020 So that means that we're so far away when our browser really is clicking enter here what it is doing 03:57.140 --> 04:06.070 is setting up a get request to our server local server telling and hey I want whatever is that slash 04:06.310 --> 04:07.130 bye. 04:07.760 --> 04:11.040 And that's simply this is basically what a request is. 04:11.150 --> 04:17.190 We are requesting resource from from the server and the server responds to us whether it's an indexed 04:17.360 --> 04:23.270 HMO page whether it's a sign whether it's you know X amount which we're not going to be talking about 04:23.700 --> 04:27.750 some kind of response and then we get it back and that's it. 04:27.800 --> 04:30.540 That's our communication server. 04:30.780 --> 04:37.110 Now the second most famous type of request is actually the post request. 04:37.130 --> 04:39.750 So what is the request what what is it. 04:39.770 --> 04:45.470 It's basically that we're requesting from the server to request to access something that we're sending 04:45.470 --> 04:46.450 to it. 04:46.490 --> 04:55.190 So we're saying hey Google or com or hey you know slash my please accept this Jason or this you know 04:55.290 --> 04:56.740 you SML or whatever. 04:56.900 --> 05:03.110 Please accept whatever I'm going to be sending you and give me a response. 05:03.200 --> 05:09.830 So it's saying hey hostess something us so so post comes from you know when you post someone in email 05:09.850 --> 05:13.270 read your postings you're sending something to him. 05:13.360 --> 05:17.220 So you're posting something to the server whatever that something is. 05:17.240 --> 05:24.040 But we're going to see how is Jason actually as you might have guessed so we're saying hey server I'm 05:24.040 --> 05:28.530 sending you some Jaison at this point please accept it. 05:28.840 --> 05:37.270 And then the server is up to the server to either accept or deny that that that that coast right because 05:37.350 --> 05:40.990 someone someone might send me some you know malware right. 05:40.990 --> 05:43.000 I don't want to accept malware. 05:43.150 --> 05:47.750 So we're going to see how we can you know authentically and against the stuff in later videos. 05:47.890 --> 05:50.200 But for now let's assume all the users are nice. 05:50.200 --> 05:50.420 Right. 05:50.420 --> 05:55.460 No is going to try to hack our Web site so people are going to be sending us some Jason. 05:55.840 --> 06:00.430 And then regarding this Jason and then we're going to say OK what are we going to do. 06:00.760 --> 06:08.590 So these are the two types of requests whenever whenever our browser wants to make a request to another 06:08.590 --> 06:17.560 server or two or really whenever any server wants to make a request to another server using HTP then 06:17.560 --> 06:24.400 it has to prepare our request and this request can be either get post or some some you know there is 06:24.480 --> 06:31.360 you know there is also I think hand and there's all sort of protocols but really these two are the most 06:31.360 --> 06:33.040 famous ones which. 06:33.070 --> 06:36.240 And we'll be spending a lot of time on those. 06:36.400 --> 06:44.680 So get get get really quick recap quickly get give me some resources at this location post Hey I'm sending 06:44.680 --> 06:51.580 you some information and I want a response so you can think of a post as you know I'm sending information 06:51.610 --> 06:55.830 plus I'm getting you know I'm expecting something in return. 06:56.490 --> 06:57.030 OK. 06:57.070 --> 07:06.430 So once Google receives this request and for example slash slides and say OK so the user wants and get 07:07.330 --> 07:09.370 ad slashed by. 07:10.000 --> 07:19.690 So I'm going to take this request and prepare what is called response to Google or even our website 07:19.780 --> 07:23.160 or our API needs to send a response right. 07:23.200 --> 07:30.880 Our response is basically saying a user sent me your request so I told him to send him back a response 07:30.880 --> 07:31.770 right. 07:31.960 --> 07:33.310 I sent someone a request. 07:33.460 --> 07:35.280 He gives me no response. 07:35.320 --> 07:37.560 So what is the structure of the response. 07:37.750 --> 07:42.420 Well the response is first made a status line. 07:42.460 --> 07:49.290 So what is the status line as status line contains one number which is status code. 07:49.690 --> 07:54.270 So status quo basically says what happened to the overall request. 07:54.460 --> 07:59.780 So for example the most common status code you would see is 200. 08:00.040 --> 08:01.050 OK. 08:01.360 --> 08:06.010 Which basically means that 200 was this request was a success. 08:06.250 --> 08:13.320 So we succeeded your request was successfully handled and this response basically means that hey I'm 08:13.330 --> 08:18.820 returning the responses that you're expecting here because your request was successful. 08:18.820 --> 08:26.320 Another one which we're always you know you always hear jokes about is 404 not found which basically 08:26.320 --> 08:32.890 means you know it can mean a lot of things but maybe even slash for example are slashed by maybe this 08:32.940 --> 08:35.570 end point is not even at the server. 08:35.620 --> 08:40.600 So it sends me a response back that Google tells me hey you know I don't have anything called slash 08:40.600 --> 08:41.010 by. 08:41.020 --> 08:50.950 Right so if I if I go back to my At-Home here and if I comment you know this all these lines of code 08:51.640 --> 08:55.460 from here to here and then I save. 08:55.660 --> 09:05.710 And then again I paused this and rerun flask and then if I try to access slash by then what I'll get 09:05.890 --> 09:08.190 is not found 404. 09:08.320 --> 09:09.100 Right. 09:09.100 --> 09:12.020 So here you will see get slashed by. 09:12.040 --> 09:14.190 But then it returns 404. 09:14.410 --> 09:16.020 That that means it's a failure. 09:16.060 --> 09:17.930 I haven't found this resource. 09:17.980 --> 09:20.300 I don't have a slash by resource here. 09:20.390 --> 09:21.040 Right. 09:21.370 --> 09:22.130 OK. 09:22.360 --> 09:23.560 Let's continue. 09:24.100 --> 09:25.950 So we get a stainless go. 09:25.960 --> 09:28.450 There are so many types of this goes right. 09:28.450 --> 09:32.390 But these two are the most famous ones we're going to see so many other ones. 09:32.470 --> 09:37.740 Others you know invalid argument invalid blah blah blah we're going to see a lot of them. 09:37.750 --> 09:44.850 So we have to return for a sustained unscrewed and then after the state is good we have to return a 09:44.860 --> 09:49.960 message body so a message body is what the user is expecting. 09:49.960 --> 09:58.430 So in our case it's going to be Jason so we're saying oh field one you know blah blah. 09:58.570 --> 10:00.400 Right. 10:00.850 --> 10:08.000 And so were so really turning some object responds body using a Jaser. 10:08.020 --> 10:14.040 So to recap really quickly we're preparing our request right. 10:14.230 --> 10:16.960 And you might be wondering for a post request right. 10:16.960 --> 10:21.360 I might have admitted this when I'm sending a post request. 10:21.360 --> 10:30.550 There is also this message body image right so I can also put message body in their quest and then I 10:30.550 --> 10:38.770 can send you know I Jason this Jason means hey this is what I'm posting to the server. 10:38.890 --> 10:45.550 Right so this server should except this post post message and then it's going to return me a status 10:45.550 --> 10:46.170 code. 10:46.330 --> 10:54.190 For example 200 and then the message body is going to be well the adjacent that I'm expecting is. 10:54.190 --> 10:55.780 So hopefully this makes sense. 10:55.780 --> 11:02.530 So to recap really quickly we have a request and then we have our response. 11:02.530 --> 11:12.800 This one could be a get slash post slash lead slash head and lots and lots of methods. 11:13.390 --> 11:17.560 And then the response should have instant Stinnes good. 11:18.550 --> 11:22.740 And then here we would have message body. 11:24.280 --> 11:26.190 In the case of the post. 11:26.410 --> 11:26.820 Right. 11:26.860 --> 11:34.110 So in the case of post we have a message body and then in the response we also have a message Varney's 11:34.110 --> 11:35.130 on this right. 11:35.240 --> 11:42.580 M-B and then it's also the sun where you can send information back to the user and that's about it. 11:42.580 --> 11:43.570 So in the next video. 11:43.600 --> 11:52.240 So for all we're doing really if we go back here oh what we've been doing really is we're simply using 11:53.910 --> 11:55.240 GET requests. 11:55.300 --> 12:00.600 If you see like Slash or slash hire there all these are we simply having an end point. 12:00.610 --> 12:04.520 We're getting an end point and we're getting a response a very basic response. 12:04.630 --> 12:05.180 Right. 12:05.440 --> 12:12.250 So in the next video we're going to see how we can as a user send send the server or something. 12:12.260 --> 12:12.680 Right. 12:12.790 --> 12:19.780 So at me as a user I want to send the server something for example to numbers and then I want to ask 12:19.780 --> 12:24.850 the server to add these two numbers and send me your response back. 12:25.390 --> 12:31.870 So instead of doing this stuff here we're going to say hey server these two numbers add them together 12:32.140 --> 12:34.270 and send me your response back. 12:34.810 --> 12:39.690 So we'll see how we can do this using a post Massad in the next. 12:40.070 --> 12:43.240 So yeah until the next video had become.