1 00:00:01,060 --> 00:00:03,440 ‫So, Mongoose offers us developers 2 00:00:03,440 --> 00:00:05,823 ‫very powerful ways of validating data 3 00:00:05,823 --> 00:00:08,280 ‫that's coming into our model. 4 00:00:08,280 --> 00:00:10,430 ‫And so, in this video you're gonna learn 5 00:00:10,430 --> 00:00:13,093 ‫all about data validation with Mongoose. 6 00:00:14,870 --> 00:00:18,110 ‫Now, what exactly does validation actually mean? 7 00:00:18,110 --> 00:00:21,470 ‫Well, validation is basically checking if the entered 8 00:00:21,470 --> 00:00:24,270 ‫values are in the right format for each field 9 00:00:24,270 --> 00:00:27,430 ‫in our document schema, and also that values 10 00:00:27,430 --> 00:00:30,860 ‫have actually been entered for all of the required fields. 11 00:00:30,860 --> 00:00:33,940 ‫Now, on the other hand, we also have sanitization, 12 00:00:33,940 --> 00:00:37,240 ‫which is to ensure that the inputted data is 13 00:00:37,240 --> 00:00:40,250 ‫basically clean, so that there is no malicious code 14 00:00:40,250 --> 00:00:42,240 ‫being injected into our database, 15 00:00:42,240 --> 00:00:44,330 ‫or into the application itself. 16 00:00:44,330 --> 00:00:47,470 ‫So, in that step we remove unwanted characters, 17 00:00:47,470 --> 00:00:50,730 ‫or even code, from the input data, all right? 18 00:00:50,730 --> 00:00:53,210 ‫And this is actually a crucial step, like, 19 00:00:53,210 --> 00:00:56,180 ‫a golden standard in back-end development. 20 00:00:56,180 --> 00:00:58,690 ‫To never, ever accept input data 21 00:00:58,690 --> 00:01:00,690 ‫coming from a user as it is. 22 00:01:00,690 --> 00:01:03,860 ‫So, we always need to sanitize that incoming data. 23 00:01:03,860 --> 00:01:06,350 ‫But, anyway, I will leave data sanitization 24 00:01:06,350 --> 00:01:08,620 ‫for the security section of the course, 25 00:01:08,620 --> 00:01:10,070 ‫so that in this lecture 26 00:01:10,070 --> 00:01:13,400 ‫we can focus entirely on data validation. 27 00:01:13,400 --> 00:01:15,430 ‫And we are doing this data validation 28 00:01:15,430 --> 00:01:17,240 ‫right here on the model. 29 00:01:17,240 --> 00:01:20,130 ‫And that, again, is because of the fat model 30 00:01:20,130 --> 00:01:22,110 ‫and thin controller philosophy, 31 00:01:22,110 --> 00:01:24,230 ‫which makes the model the perfect place 32 00:01:24,230 --> 00:01:26,770 ‫to perform validation, right? 33 00:01:26,770 --> 00:01:29,540 ‫And, in fact, Mongoose already comes with a bunch 34 00:01:29,540 --> 00:01:32,230 ‫of validation tools out of the box. 35 00:01:32,230 --> 00:01:36,120 ‫And so, let's now actually do some data validation here. 36 00:01:36,120 --> 00:01:37,680 ‫And actually, we already did. 37 00:01:37,680 --> 00:01:41,850 ‫So, when we used this require here, that is actually 38 00:01:41,850 --> 00:01:45,290 ‫already a built in data validator, all right? 39 00:01:45,290 --> 00:01:48,368 ‫So you see that we use a validator like required 40 00:01:48,368 --> 00:01:50,970 ‫right here in the schema type options. 41 00:01:50,970 --> 00:01:54,340 ‫And required is actually available for all the data types. 42 00:01:54,340 --> 00:01:56,870 ‫So, not just strings, but really everything. 43 00:01:56,870 --> 00:02:00,010 ‫Numbers, Booleans, dates, or really, 44 00:02:00,010 --> 00:02:01,930 ‫whatever type you're using. 45 00:02:01,930 --> 00:02:04,970 ‫Then we also have unique here, but please note, 46 00:02:04,970 --> 00:02:08,610 ‫that this is actually, technically, not a validator. 47 00:02:08,610 --> 00:02:10,170 ‫It will still produce an error 48 00:02:10,170 --> 00:02:12,080 ‫when we have a duplicate name, 49 00:02:12,080 --> 00:02:15,167 ‫but again, this is not really a validator, all right? 50 00:02:15,167 --> 00:02:17,790 ‫But, required is a validator, 51 00:02:17,790 --> 00:02:20,403 ‫and so I'm going to show you now another one 52 00:02:20,403 --> 00:02:23,000 ‫which is specifically just for strings, 53 00:02:23,000 --> 00:02:26,870 ‫which is called max length and also min length. 54 00:02:26,870 --> 00:02:28,160 ‫So, we have max length 55 00:02:30,320 --> 00:02:32,830 ‫and as the name says, we use this to specify 56 00:02:32,830 --> 00:02:35,470 ‫the maximum length that a string can have. 57 00:02:35,470 --> 00:02:37,490 ‫And if it's longer than that, well then, 58 00:02:37,490 --> 00:02:39,800 ‫it's going to produce an error, all right? 59 00:02:39,800 --> 00:02:42,936 ‫So, let's do that just like we did before with required, 60 00:02:42,936 --> 00:02:47,170 ‫where we specified an array, and then set the value. 61 00:02:47,170 --> 00:02:50,940 ‫So, let's say we want 40 as the maximum string length, 62 00:02:50,940 --> 00:02:53,920 ‫and then, we add the error after that. 63 00:02:53,920 --> 00:02:56,850 ‫So, basically, the error message that we get. 64 00:02:56,850 --> 00:03:01,093 ‫So, a tour name must have 65 00:03:05,410 --> 00:03:08,693 ‫less or equal then 40 characters. 66 00:03:10,880 --> 00:03:13,320 ‫Okay, so, that is max length, 67 00:03:13,320 --> 00:03:15,673 ‫and then we also have min length. 68 00:03:18,600 --> 00:03:22,480 ‫All right, and so let's set that one to 10, 69 00:03:22,480 --> 00:03:27,480 ‫so a tour name must have more or equal then 10 characters. 70 00:03:29,010 --> 00:03:33,590 ‫Okay, and so just like this we have these two validators 71 00:03:33,590 --> 00:03:37,320 ‫that are actually only available on strings, okay? 72 00:03:37,320 --> 00:03:40,690 ‫And, so let's now actually go ahead and try that. 73 00:03:40,690 --> 00:03:42,690 ‫So, I'm going to create a new tour here. 74 00:03:44,570 --> 00:03:46,453 ‫And, this is not a secret tour, 75 00:03:48,050 --> 00:03:50,183 ‫but then here the rest does not matter. 76 00:03:53,550 --> 00:03:56,100 ‫I will just call this one Test Tour, 77 00:03:56,100 --> 00:03:58,160 ‫and let's see how many characters we have, 78 00:03:58,160 --> 00:04:00,280 ‫so four plus one, plus four, 79 00:04:00,280 --> 00:04:02,130 ‫so we only have nine characters. 80 00:04:02,130 --> 00:04:05,223 ‫And so, we should now expect to actually get an error. 81 00:04:06,490 --> 00:04:07,980 ‫So, let's try that out. 82 00:04:07,980 --> 00:04:09,910 ‫And, indeed, a tour name must have 83 00:04:09,910 --> 00:04:12,460 ‫more or equal then 10 characters. 84 00:04:12,460 --> 00:04:15,873 ‫Great, but now what about updating tours? 85 00:04:17,290 --> 00:04:19,860 ‫So, let's get one of these here. 86 00:04:19,860 --> 00:04:23,910 ‫So, we have this test tour two here, 87 00:04:23,910 --> 00:04:25,963 ‫so let's try to update this one. 88 00:04:27,540 --> 00:04:30,173 ‫So, we go to our update tour route. 89 00:04:33,690 --> 00:04:38,023 ‫And now let's here, change the name to Test, 90 00:04:39,890 --> 00:04:43,240 ‫send the request, and, we get the same error. 91 00:04:43,240 --> 00:04:45,540 ‫Now, this only works because of a setting 92 00:04:45,540 --> 00:04:47,400 ‫that we set way back, 93 00:04:47,400 --> 00:04:50,600 ‫when we implemented this updating handler. 94 00:04:50,600 --> 00:04:53,853 ‫So, let me quickly show that to you in the tour controller. 95 00:04:54,860 --> 00:04:57,846 ‫Delete and update, and so it's because of this option 96 00:04:57,846 --> 00:05:00,255 ‫here runValidators, set to true 97 00:05:00,255 --> 00:05:03,180 ‫that the validators are run again. 98 00:05:03,180 --> 00:05:04,959 ‫If I set it now to false, 99 00:05:04,959 --> 00:05:09,750 ‫then Mongoose should happily accept this name. 100 00:05:09,750 --> 00:05:12,673 ‫And indeed, it does, all right. 101 00:05:14,880 --> 00:05:17,072 ‫So, let's set it back to something longer, 102 00:05:17,072 --> 00:05:18,453 ‫it doesn't matter, 103 00:05:20,630 --> 00:05:24,073 ‫okay, and if I set it back to true, 104 00:05:26,950 --> 00:05:29,070 ‫then it should not accept it, 105 00:05:29,070 --> 00:05:33,140 ‫and indeed, we get our error back, all right? 106 00:05:33,140 --> 00:05:34,540 ‫So, just wanted to quickly 107 00:05:34,540 --> 00:05:36,763 ‫show you the fact of that setting. 108 00:05:38,820 --> 00:05:42,370 ‫All right, and so, yeah, these are now working. 109 00:05:42,370 --> 00:05:46,030 ‫Let's try a couple of more validators here. 110 00:05:46,030 --> 00:05:48,450 ‫For example, now on numbers. 111 00:05:48,450 --> 00:05:51,520 ‫So, let's go here to the ratings average. 112 00:05:51,520 --> 00:05:53,370 ‫And we know that the rating must always 113 00:05:53,370 --> 00:05:57,330 ‫be between one and zero, and we know that a rating 114 00:05:57,330 --> 00:06:00,880 ‫must always be between one and five, okay? 115 00:06:00,880 --> 00:06:03,680 ‫And so, very similar to the min and max length, 116 00:06:03,680 --> 00:06:06,253 ‫on numbers we simply have min and max. 117 00:06:08,350 --> 00:06:11,353 ‫So, the minimum that we want is one, 118 00:06:15,240 --> 00:06:17,253 ‫and then again our error message. 119 00:06:18,280 --> 00:06:23,280 ‫So, rating must be above 1.0, let's say. 120 00:06:26,360 --> 00:06:29,643 ‫And then the max is five. 121 00:06:34,040 --> 00:06:38,660 ‫Must be below 5.0, okay, 122 00:06:38,660 --> 00:06:40,873 ‫and let's quickly test this one as well. 123 00:06:43,300 --> 00:06:48,300 ‫So, creating a new tour, let's call it the Test Tour Amazing 124 00:06:49,390 --> 00:06:53,933 ‫because it has an average rating of six. 125 00:06:55,020 --> 00:06:57,680 ‫Okay, so let's see what happens then, 126 00:06:57,680 --> 00:07:00,380 ‫and indeed, the rating must be below five. 127 00:07:00,380 --> 00:07:03,620 ‫Okay, and so, that again is not going to work, 128 00:07:03,620 --> 00:07:06,930 ‫and of course it cannot be zero, either. 129 00:07:06,930 --> 00:07:10,130 ‫So, it must be above one, and of course, 130 00:07:10,130 --> 00:07:14,650 ‫with four, it is gonna work, and indeed, here is our tour. 131 00:07:14,650 --> 00:07:18,180 ‫Next up, I want to restrict this difficulty value here 132 00:07:18,180 --> 00:07:20,090 ‫to only three difficulties. 133 00:07:20,090 --> 00:07:22,480 ‫So, easy, medium, and difficult. 134 00:07:22,480 --> 00:07:24,660 ‫And if the user puts in something else, 135 00:07:24,660 --> 00:07:26,360 ‫then it's not going to work. 136 00:07:26,360 --> 00:07:27,623 ‫So, let's try that out. 137 00:07:32,660 --> 00:07:36,420 ‫So, the validator that we use for that is called enum, 138 00:07:36,420 --> 00:07:38,850 ‫okay, and so, here we can pass an array 139 00:07:38,850 --> 00:07:41,403 ‫of the values, basically, that are allowed. 140 00:07:42,570 --> 00:07:47,570 ‫So, we have easy, we have medium, and we have difficult. 141 00:07:49,550 --> 00:07:53,380 ‫All right, now we also want to specify our error message 142 00:07:53,380 --> 00:07:56,870 ‫here, but right now that's not really possible, right? 143 00:07:56,870 --> 00:07:59,490 ‫I mean, if we added another argument here, 144 00:07:59,490 --> 00:08:01,330 ‫then that would not be for the error message, 145 00:08:01,330 --> 00:08:05,540 ‫it would of course be for yet another possible value, okay? 146 00:08:05,540 --> 00:08:08,200 ‫And so, the solution that we need to do here, 147 00:08:08,200 --> 00:08:10,993 ‫is to create yet another object here, 148 00:08:11,900 --> 00:08:15,613 ‫and then, actually specify that these here are the values. 149 00:08:18,870 --> 00:08:23,560 ‫And then, our message, all right? 150 00:08:23,560 --> 00:08:26,230 ‫And so, this is actually how it really works. 151 00:08:26,230 --> 00:08:29,040 ‫This notation here is really just a shorthand for 152 00:08:29,040 --> 00:08:32,763 ‫this complete object here, all right? 153 00:08:34,760 --> 00:08:39,760 ‫So, difficulty is either: easy, medium, or difficult. 154 00:08:45,280 --> 00:08:50,280 ‫Okay, and so, that is a very nice, very handy validator 155 00:08:50,323 --> 00:08:53,870 ‫that is automatically available on all strings, okay, 156 00:08:53,870 --> 00:08:57,348 ‫so, don't try to use this one here on numbers, for example. 157 00:08:57,348 --> 00:08:59,870 ‫This is only for strings. 158 00:08:59,870 --> 00:09:02,540 ‫And, by the way this min and max here 159 00:09:02,540 --> 00:09:04,450 ‫is actually not only for numbers, 160 00:09:04,450 --> 00:09:07,820 ‫but it's also gonna work with dates, all right? 161 00:09:07,820 --> 00:09:12,820 ‫Anyway, let's now finally test this out as well. 162 00:09:13,180 --> 00:09:15,399 ‫So, we need to change the name, 163 00:09:15,399 --> 00:09:17,249 ‫and in here let's put something else, 164 00:09:20,460 --> 00:09:23,233 ‫all right, and so indeed, we get our error. 165 00:09:24,770 --> 00:09:28,080 ‫If we now put easy, then it works. 166 00:09:28,080 --> 00:09:30,450 ‫Okay, and that's actually all I wanted to show you 167 00:09:30,450 --> 00:09:31,780 ‫here in this lecture, 168 00:09:31,780 --> 00:09:35,110 ‫but there are actually a bunch of other validators. 169 00:09:35,110 --> 00:09:38,259 ‫For example, on strings you have a match validator 170 00:09:38,259 --> 00:09:40,370 ‫in order to check if the input 171 00:09:40,370 --> 00:09:43,090 ‫matches a given regular expression. 172 00:09:43,090 --> 00:09:46,460 ‫But, I believe that these ones that I just showed you here 173 00:09:46,460 --> 00:09:49,250 ‫are the most important built in validators. 174 00:09:49,250 --> 00:09:51,450 ‫And, for a complete list of all of them, 175 00:09:51,450 --> 00:09:54,530 ‫of course, you can always check out the documentation. 176 00:09:54,530 --> 00:09:57,590 ‫Now we can also specify our own validators, 177 00:09:57,590 --> 00:09:59,790 ‫and so, that is exactly what we will do 178 00:09:59,790 --> 00:10:01,363 ‫right in the next video.