WEBVTT 00:03.790 --> 00:05.380 Hated everyone they share. 00:05.380 --> 00:08.920 And in this video, we're going to learn a little bit about the middleware in the Mongoose. 00:08.920 --> 00:13.780 In the last video we saw that how middleware can happen between the express routes, but it can also 00:13.780 --> 00:16.390 happen in the mongoose and tons of other libraries, too. 00:16.750 --> 00:20.170 We're going to combine this with the video where we are going to write code even as well. 00:20.170 --> 00:24.520 We're going to do a solution in this video only because I think this is a short one to explain this 00:24.520 --> 00:25.000 stuff. 00:25.300 --> 00:29.710 Okay, so let's go into the mongoose and you might already be seeing the middleware here as well. 00:29.710 --> 00:32.290 So it is available here and you can read that in Express as well. 00:32.290 --> 00:33.370 It's really the same. 00:33.490 --> 00:37.210 So what the middleware is going to do in the case of Mongoose. 00:37.240 --> 00:41.860 Now remember, Mongoose helps you to write schema as well as save that schema into the MongoDB. 00:41.890 --> 00:45.810 So it gives you mainly two types of middleware which is pre and post. 00:45.820 --> 00:50.290 Now some people you are going to see, they call it as lifecycle hooks, which is also a correct term. 00:50.290 --> 00:53.440 There is no no point in arguing that part. 00:53.440 --> 00:54.460 So we can have that. 00:54.460 --> 00:59.140 Now notice here there are types of middleware which are given to you by Mongoose as well, like validate, 00:59.140 --> 01:02.050 save, remove, update one, delete and initialize as well. 01:02.170 --> 01:04.420 We won't be going in that much of depth right now. 01:04.420 --> 01:07.090 Our focus is only onto the pre and the post. 01:07.090 --> 01:09.700 Yes, you can handle the errors and then synchronous all of that. 01:09.700 --> 01:14.230 But let me show you what happens in the pre one and after that the post one will be self explanatory 01:14.230 --> 01:14.800 to you. 01:14.890 --> 01:19.600 So notice here in the pre one it says that hey, you can define your schema like this dot, dot, dot 01:19.600 --> 01:25.120 means whatever you decide to have first name, last name, whatever you want to have it, you can have 01:25.120 --> 01:25.450 it. 01:25.450 --> 01:27.190 Now I'm saying schema dot pre. 01:27.190 --> 01:32.410 So whatever the schema you are creating, we are simply saying hey now we are saying dot pre and by 01:32.410 --> 01:36.370 the term schema here means that whatever the object that you are creating you can actually inject on 01:36.370 --> 01:36.520 that. 01:36.520 --> 01:41.880 So user dot pre or whatever you are saying inside that we pass on a hook which is save. 01:41.890 --> 01:45.550 This is basically an event like save is obviously a common event. 01:45.550 --> 01:51.340 So before just hitting the save, use this pre so what we can do we can write a function and the only 01:51.340 --> 01:56.080 thing that you have to worry about here is it doesn't accept the arrow function, so you have to use 01:56.080 --> 02:00.280 the function keyword itself, make sure there is a next being included here as well. 02:00.280 --> 02:03.970 And when the things are being done you can use the next, so do this stuff. 02:03.970 --> 02:08.500 So what I have to do this stuff here is simply take the password from the model which is being passed 02:08.500 --> 02:11.440 on to us and we just simply have to encrypt it. 02:11.440 --> 02:12.070 So that's it. 02:12.070 --> 02:13.180 That's all we have to do. 02:13.330 --> 02:19.660 Now, the bigger question is we can do that here, here at this page where the post is happening. 02:19.660 --> 02:24.430 So just after checking the user exist or not, we can actually go ahead and encrypt it here or we can 02:24.430 --> 02:25.960 write it into the module file. 02:25.960 --> 02:27.310 Both of them are correct. 02:27.310 --> 02:31.660 It just the personal perspective here, but the question is how we are going to encrypt it. 02:31.660 --> 02:32.650 That is the question now. 02:32.650 --> 02:34.630 There are so many ways to encrypted it. 02:34.990 --> 02:39.790 We're going to go to NPM JS and you're going to find that a lot of people like to use some of the crypto 02:39.790 --> 02:40.540 packages. 02:40.540 --> 02:46.090 So if I go ahead and say crypto, if I can write that, correct crypto. 02:46.510 --> 02:51.490 So crypto packages are available like crypto JS and all of that, and they can help you to actually 02:51.490 --> 02:54.760 encrypt the data based on what kind of algorithm you are using. 02:55.030 --> 03:00.160 You can pass on a nonce and the message I wouldn't be talking too much and the hash digests and nonce 03:00.160 --> 03:02.920 and all of that don't want to make it a cryptography class. 03:03.130 --> 03:04.990 So this is one way of doing it. 03:04.990 --> 03:11.770 But if you are going to search for B script, which is really an insanely popular package, B script 03:11.770 --> 03:12.250 and B script. 03:12.250 --> 03:14.520 JZ Both we are going to use the script. 03:14.530 --> 03:17.260 JS Because it is built on top of B script. 03:17.290 --> 03:22.810 Now B script is just a library to encrypt, but B script G is actually is more compatible and that's 03:22.810 --> 03:25.000 why you see insane crazy weekly download. 03:25.000 --> 03:28.450 It is kind of designed for these kinds of situations where we are facing. 03:28.450 --> 03:30.790 We are not the only one who wants to encrypt the password. 03:30.790 --> 03:32.170 There are tons of other people. 03:32.380 --> 03:34.990 So how the usage actually works, really simple. 03:34.990 --> 03:40.300 You just install it and just require it, and once you have required it, then you can go ahead and 03:40.300 --> 03:45.160 use as encryption or you can just go ahead and do all the kinds of encryption that we want. 03:45.160 --> 03:48.550 So what we'll be doing is we'll be using a hash onto it. 03:48.550 --> 03:55.450 So let me just try to find it once we have a script and then we are going to use something like not 03:55.450 --> 03:59.560 the hash sink, but we'll be using the direct hash itself and we'll be working on that. 03:59.830 --> 04:00.140 Okay. 04:00.190 --> 04:06.160 So the the biggest interesting thing about it that I wanted to show you is that you can use a big script 04:06.160 --> 04:09.070 dot compare, which is actually used to check the password. 04:09.070 --> 04:10.600 We don't want to just encrypt it. 04:10.600 --> 04:15.010 We later on want to check whether the password has whatever the login feature is. 04:15.010 --> 04:16.390 User will enter the password. 04:16.390 --> 04:21.010 We also want to check that by encrypting it that it matches with the whatever the encrypted password 04:21.010 --> 04:25.600 we have stored in the database and this entire library is built around that so we don't have to worry 04:25.600 --> 04:26.230 too much. 04:26.920 --> 04:30.370 So moving on, we get the idea that how we are going to do it, let's copy that. 04:30.370 --> 04:38.110 Move back up here and close this one and now let's go ahead and install decrypt JS shouldn't take much 04:38.110 --> 04:40.990 of the time and we can start running the dev server up here. 04:41.170 --> 04:41.430 Okay. 04:41.530 --> 04:42.460 How are we going to do that? 04:42.460 --> 04:43.210 Really simple. 04:43.210 --> 04:44.350 We have done it so many times. 04:44.350 --> 04:45.430 Shouldn't be a big deal. 04:46.180 --> 04:53.680 So first let's just go ahead and use B script and that is going to be required. 04:55.390 --> 05:03.160 Four from be correct DJs once this is being required, will go back onto the existing user. 05:03.160 --> 05:09.070 So we have checked whether the user is existing or not and after that all we've got to do is go ahead 05:09.070 --> 05:10.240 and encrypt that. 05:10.240 --> 05:13.270 So once this is all done, we have checked everything. 05:13.270 --> 05:15.040 Now let's go ahead and encrypt the password. 05:15.040 --> 05:20.170 So let's call this one as my encrypt password or whatever you want to call that. 05:20.230 --> 05:24.370 Now how we're going to design this one, that is the most interesting thing. 05:24.370 --> 05:29.890 Now, again, we haven't yet designed this one, so we can actually go ahead and call it as const or 05:29.890 --> 05:31.720 let however you like to go with that. 05:31.900 --> 05:36.730 Now, this is going to take an A wait again because it might take a little bit of time. 05:36.730 --> 05:41.530 Whenever you encrypt that, it goes through a round of algorithms and it might take a little bit time, 05:41.530 --> 05:43.930 not too much as database, but sometimes it takes. 05:44.200 --> 05:49.540 So if you go ahead and say, hey, I want to use the script and you put a dot, it has so many of the 05:49.540 --> 05:54.970 features like compare, compare, sync, decode, get the salt hash and a whole lot of other things. 05:54.970 --> 05:59.650 We're going to use just the hash because we obviously want to create the hash, the password that we 05:59.650 --> 06:01.120 grabbed from request body. 06:01.120 --> 06:05.020 And then you can go ahead and mention that how many iterations you want. 06:05.020 --> 06:10.180 The number here is how many rounds of that algorithm I have to do to encrypt it. 06:10.180 --> 06:14.680 And the more that is better, but don't do it too much because it might take some time. 06:14.680 --> 06:20.680 And sometimes even the storage capacity of particular unit or particular property in the MongoDB might 06:20.680 --> 06:21.310 exceed there. 06:21.310 --> 06:24.790 So ten is usually the good number of length to generate that. 06:25.150 --> 06:25.550 Okay. 06:25.600 --> 06:30.130 This is actually you can see here as well the salt lend to generate the salt to you. 06:30.130 --> 06:33.070 So this is basically it don't want to make it too cryptic up here. 06:33.490 --> 06:35.170 Okay, so now this is all done. 06:35.860 --> 06:40.960 So let's go ahead and construct a user because this is the object that we'll be handling over to Mongoose 06:40.960 --> 06:43.000 that, hey, just go ahead and save this one. 06:43.090 --> 06:49.570 So we're going to go ahead and say this a await and let's go ahead and use this model. 06:49.570 --> 06:55.330 So user and basically let me let me make it a little bit more simpler so that it's easier for you to 06:55.330 --> 06:55.960 understand. 06:55.960 --> 07:00.730 So we're going to take this model and we're going to say that, hey, I want to go ahead and simply 07:00.730 --> 07:01.390 create one. 07:01.390 --> 07:04.690 So this is the command to create a template that command a function. 07:04.690 --> 07:07.120 And inside this you have to pass on an object. 07:07.210 --> 07:12.730 Our object is going to be heavily, not heavily entirely dependent on the user that we have created 07:12.730 --> 07:13.390 here, the model. 07:13.390 --> 07:16.210 So first name, last name, email, password, token. 07:16.210 --> 07:18.400 We'll do we'll do something about it in a minute. 07:18.670 --> 07:18.860 Okay. 07:18.940 --> 07:19.900 So let's go up here. 07:19.900 --> 07:20.680 Sorry. 07:20.680 --> 07:21.370 There we go. 07:21.460 --> 07:26.530 So first we go ahead and say, hey, we have this first name, then we go ahead and say, hey, we have 07:26.530 --> 07:27.550 this last name. 07:27.850 --> 07:33.040 Then we go ahead and simply say, hey, we have this email, and then we simply go ahead and say, Hey, 07:33.040 --> 07:39.400 we also have this password, but this time the password, we have changed it to my encrypted password. 07:39.400 --> 07:42.460 So password will be replaced by the encrypted one and that's it. 07:42.490 --> 07:49.210 Now you will also notice that sometimes people go ahead and change this email to email to lower case 07:49.210 --> 07:49.540 command. 07:49.540 --> 07:52.840 So just me know it's not going to do that to lowercase. 07:52.840 --> 07:53.440 So there we go. 07:53.440 --> 07:56.530 It just a basic JavaScript function to just lowercase the entire email. 07:56.530 --> 08:00.220 Maybe user has entered it in a kind of weird casing and all of that. 08:00.220 --> 08:03.250 So this will actually be responsible for creating that. 08:03.250 --> 08:08.080 Now, further down the road, I told you that anything that happens with the mongoose, it's actually 08:08.080 --> 08:09.300 a dot then dot cat. 08:09.340 --> 08:10.930 So basically it's a promise. 08:10.930 --> 08:13.630 But you can go ahead in this way also. 08:13.630 --> 08:18.490 And another way of handling this situation is actually hold that into a variable just like that. 08:18.490 --> 08:23.020 But since it's a database operation, so we have to go ahead and do a wait totally up to you. 08:23.020 --> 08:24.700 Both methods are same. 08:24.700 --> 08:27.760 Use a dot, then dot catch however you want to go. 08:27.760 --> 08:29.830 That could be much more easier than this. 08:30.160 --> 08:32.080 Okay, so this is all done. 08:32.080 --> 08:35.710 We have saved the user yet, but the job is not done. 08:35.710 --> 08:41.500 Because if I go back up here onto the presentation, I've said that take care of the password. 08:41.500 --> 08:42.340 We have done that. 08:42.340 --> 08:46.570 Now we have to either generate that token or send the success message. 08:46.570 --> 08:50.470 I prefer to not send the success message because that would be easier. 08:50.470 --> 08:54.820 I will choose the little bit of path here to generate token because obviously we haven't talked about 08:54.820 --> 08:55.480 the token yet. 08:55.480 --> 08:56.530 So it's time now. 08:56.530 --> 08:58.870 Let's go ahead and talk about the tokens.