1 1 00:00:00,780 --> 00:00:01,940 Hi and welcome back. 2 2 00:00:01,940 --> 00:00:04,140 In this video we're going to bring decorators 3 3 00:00:04,140 --> 00:00:05,870 over to our web application 4 4 00:00:05,870 --> 00:00:07,520 so that we can use them 5 5 00:00:07,520 --> 00:00:10,713 to limit who can access certain endpoints. 6 6 00:00:11,640 --> 00:00:16,640 What am gonna do is am gonna go over to my alerts views. 7 7 00:00:17,010 --> 00:00:19,550 And here we're gonna apply the decorator 8 8 00:00:19,550 --> 00:00:20,950 to a bunch of these. 9 9 00:00:20,950 --> 00:00:22,590 And we haven't defined the decorator yet, 10 10 00:00:22,590 --> 00:00:23,700 we gonna do that in just a moment. 11 11 00:00:23,700 --> 00:00:28,440 So we gonna say from models.user input requires login. 12 12 00:00:28,440 --> 00:00:30,950 That's what our decorator is gonna be called. 13 13 00:00:30,950 --> 00:00:32,493 And now you're under the last video. 14 14 00:00:32,493 --> 00:00:36,880 What we going to do is we're gonna say the index function 15 15 00:00:37,780 --> 00:00:41,510 is the index function but passed through 16 16 00:00:41,510 --> 00:00:44,006 the requires login decorator. 17 17 00:00:44,006 --> 00:00:45,210 And what that's gonna do 18 18 00:00:45,210 --> 00:00:47,610 is before running the index function, 19 19 00:00:47,610 --> 00:00:50,310 we're going to check whether the users logged in 20 20 00:00:50,310 --> 00:00:54,170 and only if they are will we run the original function. 21 21 00:00:54,170 --> 00:00:57,923 If they are not, we will send them over to the login page. 22 22 00:00:58,810 --> 00:01:01,220 And then we gonna do the same for new alert. 23 23 00:01:01,220 --> 00:01:03,810 The new alert function will be the new alert function 24 24 00:01:03,810 --> 00:01:07,480 but passed through the requires login decorator. 25 25 00:01:07,480 --> 00:01:08,820 Which once again will do the same thing, 26 26 00:01:08,820 --> 00:01:11,240 it'll check to see if the users logged in. 27 27 00:01:11,240 --> 00:01:14,460 And if they are, we will run the original function, 28 28 00:01:14,460 --> 00:01:16,110 and so on for the others as well. 29 29 00:01:17,220 --> 00:01:20,340 So how do we apply a decorator in the real world? 30 30 00:01:20,340 --> 00:01:21,770 Because we're not gonna do 31 31 00:01:24,540 --> 00:01:28,670 index equal requires login index. 32 32 00:01:28,670 --> 00:01:31,990 Although I'm not entirely unconvinced this wouldn't work. 33 33 00:01:31,990 --> 00:01:33,170 But there's a better way 34 34 00:01:33,170 --> 00:01:35,960 of applying decorators of doing essentially that. 35 35 00:01:35,960 --> 00:01:39,100 And that is this syntax up here. 36 36 00:01:39,100 --> 00:01:42,840 The at syntax in front of a function is a decorator. 37 37 00:01:42,840 --> 00:01:46,240 And what it does is it passes the index function 38 38 00:01:46,240 --> 00:01:47,423 through the decorator. 39 39 00:01:48,430 --> 00:01:51,130 And then this function only runs 40 40 00:01:51,130 --> 00:01:53,690 when the decorator allows it to essentially, 41 41 00:01:53,690 --> 00:01:56,260 the decorator is used to extend it. 42 42 00:01:56,260 --> 00:01:58,040 The decorator can also do other things 43 43 00:01:58,040 --> 00:02:00,610 other than prevent access to a function. 44 44 00:02:00,610 --> 00:02:02,210 It can do a number of things 45 45 00:02:02,210 --> 00:02:04,880 run other functions before this function runs 46 46 00:02:04,880 --> 00:02:07,810 or run other functions after this function runs, 47 47 00:02:07,810 --> 00:02:12,393 for example to do logging or anything else. 48 48 00:02:13,770 --> 00:02:17,760 So we gonna to apply our requires login decorator 49 49 00:02:17,760 --> 00:02:19,400 to this function. 50 50 00:02:19,400 --> 00:02:20,980 And also to this one, and to this one 51 51 00:02:23,770 --> 00:02:25,490 and to this one. 52 52 00:02:25,490 --> 00:02:27,570 Now it's very important in flask 53 53 00:02:27,570 --> 00:02:29,560 that the requires login decorator 54 54 00:02:29,560 --> 00:02:34,490 goes underneath the route decorator and not above it. 55 55 00:02:34,490 --> 00:02:36,670 So make sure that the order of decorators is like this 56 56 00:02:36,670 --> 00:02:38,390 because it matters. 57 57 00:02:38,390 --> 00:02:41,860 Otherwise, you'd be trying to assert the users logged in 58 58 00:02:41,860 --> 00:02:43,530 before you even know what endpoint 59 59 00:02:43,530 --> 00:02:45,120 they are trying to retrieve, 60 60 00:02:45,120 --> 00:02:47,420 which wouldn't really make sense. 61 61 00:02:47,420 --> 00:02:49,490 So make sure the order is like this. 62 62 00:02:49,490 --> 00:02:53,130 And now we can go ahead and implement our decorator. 63 63 00:02:53,130 --> 00:02:54,810 We gonna go into user 64 64 00:02:54,810 --> 00:02:56,690 and create a new file that am gonna call 65 65 00:02:56,690 --> 00:02:59,350 decorators.py 66 66 00:02:59,350 --> 00:03:02,550 and then here we gonna write our decorator. 67 67 00:03:02,550 --> 00:03:04,350 In order to write a decorator that 68 68 00:03:04,350 --> 00:03:06,990 fully complies with what a decorator should do, 69 69 00:03:06,990 --> 00:03:09,490 we need to import a module that comes with Python 70 70 00:03:09,490 --> 00:03:12,730 called functools for function tools. 71 71 00:03:12,730 --> 00:03:15,083 And from typing we're gonna import callable. 72 72 00:03:15,920 --> 00:03:19,470 Then from flask we're gonna import session, flash, 73 73 00:03:19,470 --> 00:03:22,180 redirect, URL for, and request. 74 74 00:03:22,180 --> 00:03:23,510 We gonna use all of these things 75 75 00:03:23,510 --> 00:03:25,110 in just a few lines. 76 76 00:03:25,110 --> 00:03:27,500 By the way flash, has nothing to do with 77 77 00:03:27,500 --> 00:03:29,990 this technology used for displaying graphics. 78 78 00:03:29,990 --> 00:03:30,990 It's something else. 79 79 00:03:31,990 --> 00:03:35,600 Then we gonna define our requires login decorator, 80 80 00:03:35,600 --> 00:03:38,130 which is gonna take in that funk function, 81 81 00:03:38,130 --> 00:03:41,300 or let me gonna call it F for shortness. 82 82 00:03:41,300 --> 00:03:45,600 And as we know, F is a function 83 83 00:03:45,600 --> 00:03:48,490 and in a typing module functions or other things you can 84 84 00:03:48,490 --> 00:03:51,750 call or execute are called callables. 85 85 00:03:51,750 --> 00:03:55,020 So F is a callable and this requires login decorator 86 86 00:03:55,020 --> 00:03:56,820 as you remember from the last video, 87 87 00:03:56,820 --> 00:03:59,143 will also return a callable. 88 88 00:04:00,530 --> 00:04:03,673 Then we gonna have our decorated function. 89 89 00:04:04,980 --> 00:04:07,240 This decorated function, 90 90 00:04:07,240 --> 00:04:10,110 which is this index function really 91 91 00:04:10,110 --> 00:04:12,890 well this index function will be replaced 92 92 00:04:12,890 --> 00:04:14,823 by this decorated function. 93 93 00:04:16,110 --> 00:04:19,460 Often doesn't take any arguments. 94 94 00:04:19,460 --> 00:04:23,510 But sometimes it does take some arguments like alert ID. 95 95 00:04:23,510 --> 00:04:26,290 So we wanna make sure that these decorated function 96 96 00:04:26,290 --> 00:04:28,880 can also take arguments. 97 97 00:04:28,880 --> 00:04:30,883 The way we do that in Python is we say, 98 98 00:04:32,520 --> 00:04:36,790 asterisk args, an asterisk asterisk kwargs 99 99 00:04:36,790 --> 00:04:39,500 for arguments and keyword arguments 100 100 00:04:39,500 --> 00:04:40,870 and in Python this means that 101 101 00:04:40,870 --> 00:04:43,280 it can have any number of arguments, 102 102 00:04:43,280 --> 00:04:46,293 and it can also have any number of keyword arguments. 103 103 00:04:47,460 --> 00:04:48,620 Why does that matter? 104 104 00:04:48,620 --> 00:04:51,760 Well, because we don't know how many or which arguments 105 105 00:04:51,760 --> 00:04:53,100 a function is gonna have. 106 106 00:04:53,100 --> 00:04:55,580 These ones have an argument called alert ID, 107 107 00:04:55,580 --> 00:04:59,400 but also others have an argument called store ID. 108 108 00:04:59,400 --> 00:05:02,830 So because we don't know exactly what arguments it has, 109 109 00:05:02,830 --> 00:05:06,720 we gonna accept any number of arguments in this function. 110 110 00:05:06,720 --> 00:05:10,100 And then we gonna say, 111 111 00:05:10,100 --> 00:05:12,990 if not session get email, 112 112 00:05:12,990 --> 00:05:17,240 i.e. if there is no email inside the session variable, 113 113 00:05:17,240 --> 00:05:19,253 which again we've imported from flask, 114 114 00:05:20,290 --> 00:05:22,580 then we're going to flash a message 115 115 00:05:22,580 --> 00:05:27,020 saying you need to be signed in for this page. 116 116 00:05:27,020 --> 00:05:30,040 And then this takes in a second argument, 117 117 00:05:30,040 --> 00:05:32,410 which is gonna be danger. 118 118 00:05:32,410 --> 00:05:34,010 Because this is a dangerous message, 119 119 00:05:34,010 --> 00:05:35,180 now because we're gonna just show 120 120 00:05:35,180 --> 00:05:36,940 an error message to the user. 121 121 00:05:36,940 --> 00:05:39,220 And this is what flash is for. 122 122 00:05:39,220 --> 00:05:44,160 Flash, places this message into a queue of messages, 123 123 00:05:44,160 --> 00:05:45,730 and then from your templates, 124 124 00:05:45,730 --> 00:05:48,410 you can get all the messages from the queue 125 125 00:05:48,410 --> 00:05:50,000 and display them to the user. 126 126 00:05:50,000 --> 00:05:52,203 So is actually a pretty handy way of just, 127 127 00:05:53,050 --> 00:05:54,890 putting things out into a queue, 128 128 00:05:54,890 --> 00:05:57,700 so that when the user actually sees them, 129 129 00:05:57,700 --> 00:05:59,060 you can show them all. 130 130 00:05:59,060 --> 00:06:01,060 And here we're just gonna show this one. 131 131 00:06:02,210 --> 00:06:03,820 Once we flash this message, 132 132 00:06:03,820 --> 00:06:06,540 we gonna return a redirect 133 133 00:06:06,540 --> 00:06:11,180 of URL for to users.login user. 134 134 00:06:11,180 --> 00:06:12,370 What this is gonna do 135 135 00:06:12,370 --> 00:06:16,110 is it's going to store this message into this queue 136 136 00:06:16,110 --> 00:06:19,220 and then it's gonna send the user over to the login page. 137 137 00:06:19,220 --> 00:06:20,520 In the login page, 138 138 00:06:20,520 --> 00:06:22,470 we would then show this message. 139 139 00:06:22,470 --> 00:06:24,870 And we have to do that we haven't done that yet. 140 140 00:06:26,110 --> 00:06:28,360 If we don't do this, 141 141 00:06:28,360 --> 00:06:32,350 it means that we do have an email in the session, 142 142 00:06:32,350 --> 00:06:35,000 because this would evaluate to false. 143 143 00:06:35,000 --> 00:06:37,640 So if we do have an email in the session, 144 144 00:06:37,640 --> 00:06:39,470 then we gonna return 145 145 00:06:39,470 --> 00:06:42,317 F with args and kwargs. 146 146 00:06:44,520 --> 00:06:45,353 And what that's gonna do 147 147 00:06:45,353 --> 00:06:47,870 is it's gonna take all the arguments and keyword arguments 148 148 00:06:47,870 --> 00:06:50,200 that this function may have taken, 149 149 00:06:50,200 --> 00:06:53,313 and it's gonna call the original function with all of those. 150 150 00:06:54,250 --> 00:06:58,330 Remember, these decorated function becomes 151 151 00:06:58,330 --> 00:07:00,040 each of these functions. 152 152 00:07:00,040 --> 00:07:03,100 So when flask calls it in order to evaluate 153 153 00:07:03,100 --> 00:07:05,140 what to return for our users, 154 154 00:07:05,140 --> 00:07:07,960 it will pass the alert ID. 155 155 00:07:07,960 --> 00:07:10,430 So that's this function getting the alert ID. 156 156 00:07:10,430 --> 00:07:12,180 So that's why it needs to take in 157 157 00:07:12,180 --> 00:07:13,830 arguments and keyword arguments, 158 158 00:07:13,830 --> 00:07:15,450 but it needs to pass them 159 159 00:07:15,450 --> 00:07:17,310 to our original function which is the one 160 160 00:07:17,310 --> 00:07:19,053 that's actually doing the work. 161 161 00:07:20,920 --> 00:07:24,220 Finally, we return decorated function. 162 162 00:07:24,220 --> 00:07:27,520 Make sure to not include brackets at the end. 163 163 00:07:27,520 --> 00:07:29,870 We wanna return the function itself, 164 164 00:07:29,870 --> 00:07:33,313 not the decorated function execution. 165 165 00:07:34,850 --> 00:07:36,700 Actually thinking we don't need requests anymore, 166 166 00:07:36,700 --> 00:07:38,450 this is everything that we do need. 167 167 00:07:39,820 --> 00:07:43,710 Now, when we apply this decorator to one of these functions, 168 168 00:07:43,710 --> 00:07:46,173 essentially it becomes replaced. 169 169 00:07:47,290 --> 00:07:49,603 And that has some implications. 170 170 00:07:50,600 --> 00:07:53,890 For example, this function is called delete alert. 171 171 00:07:53,890 --> 00:07:58,120 But when it gets replaced by this function, 172 172 00:07:58,120 --> 00:08:00,730 what will the function name be? 173 173 00:08:00,730 --> 00:08:01,760 Well, you guessed it, 174 174 00:08:01,760 --> 00:08:04,163 the function name will be decorated function. 175 175 00:08:05,660 --> 00:08:08,030 Another thing, functions in Python 176 176 00:08:08,030 --> 00:08:09,740 can have documentation applying to them. 177 177 00:08:09,740 --> 00:08:11,710 Not sure if you knew this but 178 178 00:08:11,710 --> 00:08:14,630 for any function you can write how it should be used 179 179 00:08:14,630 --> 00:08:18,810 or who should use it or when it gets cold or anything else. 180 180 00:08:18,810 --> 00:08:20,870 And then from within Python code, 181 181 00:08:20,870 --> 00:08:24,313 you can read this documentation by using help tools. 182 182 00:08:25,890 --> 00:08:26,900 But you guessed it 183 183 00:08:26,900 --> 00:08:29,980 when this function becomes replaced by this one, 184 184 00:08:29,980 --> 00:08:31,460 it does not have documentation 185 185 00:08:31,460 --> 00:08:33,910 because this function doesn't have documentation. 186 186 00:08:35,600 --> 00:08:38,820 That's where funk tools comes into play. 187 187 00:08:38,820 --> 00:08:42,670 We can use funk tools to tell this function 188 188 00:08:42,670 --> 00:08:46,120 to take in the name and documentation 189 189 00:08:46,120 --> 00:08:47,920 of the original function 190 190 00:08:47,920 --> 00:08:51,823 and use those instead of the ones that are here. 191 191 00:08:53,430 --> 00:08:54,263 So it's gonna take 192 192 00:08:54,263 --> 00:08:57,230 any identifying information of the original function 193 193 00:08:57,230 --> 00:09:01,060 and this function will at the time that this is evaluated, 194 194 00:09:01,060 --> 00:09:03,943 use the original functions identifying information. 195 195 00:09:04,810 --> 00:09:08,040 And that is what makes decorators so powerful. 196 196 00:09:08,040 --> 00:09:11,690 Because really, this function no longer gets deleted 197 197 00:09:11,690 --> 00:09:13,760 or ignored or forgotten, 198 198 00:09:13,760 --> 00:09:17,143 it just becomes extended by this stuff here. 199 199 00:09:18,420 --> 00:09:22,343 And funnily enough, the way you use functools 200 200 00:09:23,920 --> 00:09:25,640 is with another decorator. 201 201 00:09:25,640 --> 00:09:28,180 So you need a decorator in order 202 202 00:09:29,350 --> 00:09:31,210 to define a decorator. 203 203 00:09:31,210 --> 00:09:33,100 Well, you don't really need it, 204 204 00:09:33,100 --> 00:09:35,240 you can ignore this line if you want, 205 205 00:09:35,240 --> 00:09:38,090 but it is what keeps the original name and documentation. 206 206 00:09:39,400 --> 00:09:44,400 So that's a pretty interesting quirk about decorators 207 207 00:09:44,620 --> 00:09:47,963 that you need a decorator in order to define one. 208 208 00:09:48,880 --> 00:09:49,713 But that's it. 209 209 00:09:49,713 --> 00:09:51,820 This is our decorator, I hope that makes sense. 210 210 00:09:51,820 --> 00:09:54,400 Decorators are quite mind twisting 211 211 00:09:54,400 --> 00:09:55,610 when you first look at them. 212 212 00:09:55,610 --> 00:09:57,940 So I hope that you're not too confused 213 213 00:09:57,940 --> 00:10:01,300 and I would recommend that you define and use a few of them 214 214 00:10:01,300 --> 00:10:04,103 to get more acquainted with how they work. 215 215 00:10:06,580 --> 00:10:07,850 But that's it. 216 216 00:10:07,850 --> 00:10:10,830 Now these decorators will prevent users 217 217 00:10:10,830 --> 00:10:13,100 from accessing these pages 218 218 00:10:13,100 --> 00:10:15,910 unless they are logged in. 219 219 00:10:15,910 --> 00:10:18,673 And we can verify that by running the app. 220 220 00:10:19,830 --> 00:10:22,260 Oh, we do have something else that we've forgotten, 221 221 00:10:22,260 --> 00:10:26,280 which is that here we've imported from models.user, 222 222 00:10:26,280 --> 00:10:30,300 which means the init method of the models.user folder, 223 223 00:10:30,300 --> 00:10:32,290 we do have to say from 224 224 00:10:32,290 --> 00:10:37,290 models user decorators import requires login. 225 225 00:10:38,010 --> 00:10:39,233 Now we can run our app. 226 226 00:10:40,310 --> 00:10:42,810 Then we can go over to Chrome, 227 227 00:10:42,810 --> 00:10:44,530 which we've got here. 228 228 00:10:44,530 --> 00:10:49,380 And we are going to go over to our alerts page. 229 229 00:10:49,380 --> 00:10:51,100 But as you can see it instantly 230 230 00:10:51,100 --> 00:10:53,003 redirects us to the login page. 231 231 00:10:54,850 --> 00:10:57,860 Because we've got this requires login decorator here 232 232 00:10:57,860 --> 00:11:01,610 before we evaluate any of this, 233 233 00:11:01,610 --> 00:11:04,900 we're actually going through this decorated function. 234 234 00:11:04,900 --> 00:11:07,730 And because we don't have email in the session, 235 235 00:11:07,730 --> 00:11:09,830 we just restarted our app. 236 236 00:11:09,830 --> 00:11:12,463 Then it redirects us to the login user page. 237 237 00:11:13,490 --> 00:11:14,483 And now the question is, 238 238 00:11:14,483 --> 00:11:16,633 well what happened to this flashed message? 239 239 00:11:17,530 --> 00:11:20,360 We haven't shown the flashed message yet. 240 240 00:11:20,360 --> 00:11:22,690 So we're gonna do that just now. 241 241 00:11:22,690 --> 00:11:24,993 In our base.html. 242 242 00:11:27,450 --> 00:11:30,880 We gonna do that in base.html and not in net login. 243 243 00:11:30,880 --> 00:11:33,080 Because just in case another part of our app 244 244 00:11:33,080 --> 00:11:35,020 wants to flash a message as well, 245 245 00:11:35,020 --> 00:11:38,260 we can put it here and then anytime any part of our app 246 246 00:11:38,260 --> 00:11:40,610 flashes a message, it will be displayed 247 247 00:11:40,610 --> 00:11:41,540 and we don't have to like 248 248 00:11:41,540 --> 00:11:44,850 copy this code into everything else that we'll be doing. 249 249 00:11:44,850 --> 00:11:47,650 You'll see what this code does in just a moment. 250 250 00:11:47,650 --> 00:11:48,503 We gonna say, 251 251 00:11:50,220 --> 00:11:55,173 with messages equal get flashed messages. 252 252 00:11:56,770 --> 00:11:58,100 And we gonna pass in with 253 253 00:11:58,100 --> 00:12:00,320 categories equal true endwith. 254 254 00:12:04,387 --> 00:12:07,980 And what this does is it defines a variable called messages, 255 255 00:12:07,980 --> 00:12:10,340 but only the variable only exists 256 256 00:12:10,340 --> 00:12:11,533 inside this block. 257 257 00:12:12,460 --> 00:12:14,880 So this is a ginger way of defining a variable 258 258 00:12:14,880 --> 00:12:16,620 that has a limited lifetime, 259 259 00:12:16,620 --> 00:12:18,910 it only lives within this block. 260 260 00:12:18,910 --> 00:12:21,963 Then we gonna say if messages exists. 261 261 00:12:24,660 --> 00:12:25,810 Now we wanna show them, 262 262 00:12:26,661 --> 00:12:30,823 we gonna say, for category message in messages. 263 263 00:12:34,900 --> 00:12:39,810 And here we will show a div that has a class of alert, 264 264 00:12:39,810 --> 00:12:42,363 alert dash category. 265 265 00:12:44,070 --> 00:12:45,740 And the role is going to be alert. 266 266 00:12:45,740 --> 00:12:47,160 This is for screen reader software 267 267 00:12:47,160 --> 00:12:48,680 to know what this is all about. 268 268 00:12:48,680 --> 00:12:51,743 And inside it, we're gonna put the message. 269 269 00:12:52,860 --> 00:12:56,520 So category is that danger 270 270 00:12:57,700 --> 00:13:00,603 and the message is the content. 271 271 00:13:02,700 --> 00:13:05,260 So for each one of them, as long as there's any of them. 272 272 00:13:05,260 --> 00:13:06,640 We're gonna show these div 273 273 00:13:06,640 --> 00:13:10,610 with two classes alert and alert dash danger. 274 274 00:13:10,610 --> 00:13:12,130 The role is gonna be alert and inside it, 275 275 00:13:12,130 --> 00:13:14,670 we gonna have our message. 276 276 00:13:14,670 --> 00:13:19,090 This is a bootstrap alert when it has these two classes, 277 277 00:13:19,090 --> 00:13:21,270 so it's gonna style it like bootstrap boot. 278 278 00:13:21,270 --> 00:13:24,170 If you don't put the classes in, it'll just show the text. 279 279 00:13:25,060 --> 00:13:29,053 Alright let's restart our app and go back into Chrome. 280 280 00:13:30,200 --> 00:13:32,140 If you refresh this page by the way, 281 281 00:13:32,140 --> 00:13:34,780 you are in users login. 282 282 00:13:34,780 --> 00:13:37,470 So you not actually running the decorator. 283 283 00:13:37,470 --> 00:13:41,670 The decorator only runs when you access the alert endpoints. 284 284 00:13:41,670 --> 00:13:44,170 So you do have to go back to alerts. 285 285 00:13:44,170 --> 00:13:46,900 And there you get the alert. 286 286 00:13:46,900 --> 00:13:49,430 You need to be signed in for this page 287 287 00:13:51,059 --> 00:13:55,120 Let's just gonna make a small edit into this base.html. 288 288 00:13:55,120 --> 00:13:59,800 Am gonna add mt dash two for margin top small. 289 289 00:13:59,800 --> 00:14:02,683 So that when you see the alert, 290 290 00:14:03,700 --> 00:14:06,240 it'll have a small gap at the top. 291 291 00:14:06,240 --> 00:14:08,103 Just looks a little bit nicer and I think. 292 292 00:14:09,060 --> 00:14:10,090 And that's it. 293 293 00:14:10,090 --> 00:14:13,400 That's how you make sure that users are logged in 294 294 00:14:13,400 --> 00:14:16,080 before they access one of your endpoints. 295 295 00:14:16,080 --> 00:14:19,310 And you've also learned about message flashing in flask, 296 296 00:14:19,310 --> 00:14:22,363 which is actually a pretty nice feature of the library. 297 297 00:14:23,780 --> 00:14:25,650 So thank you for joining me in this video. 298 298 00:14:25,650 --> 00:14:27,020 I hope you've learned something. 299 299 00:14:27,020 --> 00:14:28,503 I'll see you on the next one.