1 00:00:02,010 --> 00:00:04,750 Hi, and welcome back. 2 00:00:04,750 --> 00:00:08,060 This video is recorded a little bit after 3 00:00:08,060 --> 00:00:09,270 the rest of the course, 4 00:00:09,270 --> 00:00:12,070 so you may see a little difference 5 00:00:12,070 --> 00:00:14,240 between the other videos in the course 6 00:00:14,240 --> 00:00:15,870 and this section. 7 00:00:15,870 --> 00:00:17,850 Please bear with me while I explain then 8 00:00:17,850 --> 00:00:20,433 and also while I bring you up to speed. 9 00:00:21,310 --> 00:00:25,380 So what we've got here is Visual Studio Code. 10 00:00:25,380 --> 00:00:27,300 This is changed from Atom. 11 00:00:27,300 --> 00:00:29,480 So in the rest of the course we were using Atom. 12 00:00:29,480 --> 00:00:30,800 Now I'm using Visual Studio Code 13 00:00:30,800 --> 00:00:32,690 just because a few months have passed. 14 00:00:32,690 --> 00:00:34,380 I've come to the conclusion 15 00:00:34,380 --> 00:00:36,720 that Visual Studio Code is a bit better, 16 00:00:36,720 --> 00:00:38,890 a bit nicer to work with, 17 00:00:38,890 --> 00:00:40,020 just looks a bit nicer. 18 00:00:40,020 --> 00:00:42,850 It has more integrations with things. 19 00:00:42,850 --> 00:00:44,220 If you wanna keep using Atom, 20 00:00:44,220 --> 00:00:45,870 by all means do that. 21 00:00:45,870 --> 00:00:49,590 I'm just using Visual Studio Code now more often. 22 00:00:49,590 --> 00:00:51,363 So that's why I'm using that. 23 00:00:52,270 --> 00:00:53,970 All of the time I'm also using PyCharm. 24 00:00:53,970 --> 00:00:56,100 So still can use that if you want. 25 00:00:56,100 --> 00:00:57,513 It's also a very good tool. 26 00:00:58,680 --> 00:01:02,300 For our all intents and purposes it's gonna be the same. 27 00:01:02,300 --> 00:01:03,900 So you're not gonna notice any difference 28 00:01:03,900 --> 00:01:05,930 between the rest of the course and this one. 29 00:01:05,930 --> 00:01:07,230 Just the editor looks a little bit different, 30 00:01:07,230 --> 00:01:08,163 but that's it. 31 00:01:09,920 --> 00:01:12,370 Now, in this section 32 00:01:12,370 --> 00:01:17,160 we are going to look at Flask-JWT-Extended. 33 00:01:17,160 --> 00:01:19,440 A lot of you have asked for this section 34 00:01:19,440 --> 00:01:21,310 to be included in the course 35 00:01:21,310 --> 00:01:24,840 because it contains a key piece of functionality 36 00:01:24,840 --> 00:01:26,330 when we develop authentication 37 00:01:26,330 --> 00:01:30,253 in our REST APIs, which is token refreshing. 38 00:01:31,130 --> 00:01:35,450 Token refreshing allows you to get a new JWT 39 00:01:35,450 --> 00:01:38,120 without asking your users for their username 40 00:01:38,120 --> 00:01:39,730 and password again. 41 00:01:39,730 --> 00:01:43,490 If your JWT expires after say 10 minutes, 42 00:01:43,490 --> 00:01:45,060 every 10 minutes you have to ask your users 43 00:01:45,060 --> 00:01:46,750 for username and password 44 00:01:46,750 --> 00:01:49,440 if you don't use token refreshing. 45 00:01:49,440 --> 00:01:52,370 So we're going to look at Flask-JWT-Extended 46 00:01:52,370 --> 00:01:54,020 because it supports that, 47 00:01:54,020 --> 00:01:55,680 but, of course, I'm also going to guide you 48 00:01:55,680 --> 00:01:58,120 through using Flask-JWT-Extended 49 00:01:58,120 --> 00:02:01,120 like we have done with Flask-JWT, 50 00:02:01,120 --> 00:02:03,530 but, because you already know a bunch of stuff, 51 00:02:03,530 --> 00:02:05,530 we don't have to cover absolutely everything 52 00:02:05,530 --> 00:02:07,560 in very slow detail. 53 00:02:07,560 --> 00:02:08,950 We can go quite quickly 54 00:02:08,950 --> 00:02:11,620 because a lot of thing are very similar. 55 00:02:11,620 --> 00:02:14,130 Now this code that you see here 56 00:02:14,130 --> 00:02:15,890 is more or less exactly the same 57 00:02:15,890 --> 00:02:18,060 as the code that we had 58 00:02:18,060 --> 00:02:19,610 at the end of the last section. 59 00:02:20,650 --> 00:02:22,180 There are a couple differences, 60 00:02:22,180 --> 00:02:23,370 and I'm going to highlight them 61 00:02:23,370 --> 00:02:25,610 for you in this video. 62 00:02:25,610 --> 00:02:28,880 So please take the code that I provide 63 00:02:28,880 --> 00:02:30,570 at the start of this section. 64 00:02:30,570 --> 00:02:33,740 It's linked in the resources of this lecture. 65 00:02:33,740 --> 00:02:34,970 It's called the starter code, 66 00:02:34,970 --> 00:02:37,640 and that's the starter code for this section. 67 00:02:37,640 --> 00:02:40,100 So you can feel free to download that 68 00:02:40,100 --> 00:02:41,490 and give it a go. 69 00:02:41,490 --> 00:02:43,110 It'll be more or less the same 70 00:02:43,110 --> 00:02:44,910 as what we've already got. 71 00:02:44,910 --> 00:02:45,930 For the rest of the section 72 00:02:45,930 --> 00:02:47,810 I recommend you use this code 73 00:02:47,810 --> 00:02:50,100 as opposed to the one in the last section 74 00:02:50,100 --> 00:02:51,810 because of these minor difference 75 00:02:51,810 --> 00:02:54,050 that I'm about to tell you about. 76 00:02:54,050 --> 00:02:57,190 The first minor difference is this line here. 77 00:02:57,190 --> 00:02:59,623 App.confige PROPAGATE_EXCEPTIONS is true. 78 00:03:00,870 --> 00:03:01,880 What does this mean? 79 00:03:01,880 --> 00:03:05,020 Well, turns out when you're running your Flask app, 80 00:03:05,020 --> 00:03:08,100 if Flask-JWT raises an error, 81 00:03:08,100 --> 00:03:11,210 your Flask app is not going to see that error. 82 00:03:11,210 --> 00:03:14,280 For example, let's say Flask-JWT raises 83 00:03:14,280 --> 00:03:15,970 not authorised error, 84 00:03:15,970 --> 00:03:19,530 and it tries to return an error code 401, 85 00:03:19,530 --> 00:03:22,850 which means unauthorised in the HTTP codes. 86 00:03:22,850 --> 00:03:24,530 If you don't have this, 87 00:03:24,530 --> 00:03:26,380 your Flask app is actually just going to return 88 00:03:26,380 --> 00:03:27,700 an error code 500. 89 00:03:27,700 --> 00:03:29,620 It's going to say, sorry, 90 00:03:29,620 --> 00:03:31,030 I don't know what to do, 91 00:03:31,030 --> 00:03:33,310 so I'm just gonna give you an error. 92 00:03:33,310 --> 00:03:35,110 If you allow PROPAGATE_EXCEPTIONS, 93 00:03:35,110 --> 00:03:37,290 that means that the Flask extensions 94 00:03:37,290 --> 00:03:42,290 like Flask-JWT can raise their own exceptions 95 00:03:42,330 --> 00:03:44,690 and return their own codes 96 00:03:44,690 --> 00:03:46,530 and their own message to the user, 97 00:03:46,530 --> 00:03:47,970 so you would be then returning 98 00:03:47,970 --> 00:03:51,920 a specific error that Flask-JWT has told you 99 00:03:51,920 --> 00:03:54,470 or told your app to return. 100 00:03:54,470 --> 00:03:57,150 So that lets your exception return 101 00:03:57,150 --> 00:03:58,680 their own custom errors, 102 00:03:58,680 --> 00:04:00,783 which can be really handy at times. 103 00:04:02,320 --> 00:04:06,210 Now, there are a couple other small changes. 104 00:04:06,210 --> 00:04:08,780 For example, here I'm going to the item resource, 105 00:04:08,780 --> 00:04:10,590 and you'll see that most things 106 00:04:10,590 --> 00:04:12,220 are more or less the same. 107 00:04:12,220 --> 00:04:13,900 There are a couple of differences here. 108 00:04:13,900 --> 00:04:15,610 Previously in the last code 109 00:04:15,610 --> 00:04:20,083 we had them ItemModel passing in data, 110 00:04:21,010 --> 00:04:23,030 price like that. 111 00:04:23,030 --> 00:04:27,950 Now we are passing in the unpacked data, 112 00:04:27,950 --> 00:04:31,013 which means it contains everything in a dictionary, 113 00:04:32,220 --> 00:04:33,900 store ID and price. 114 00:04:33,900 --> 00:04:35,970 So that store ID and price are getting passed 115 00:04:35,970 --> 00:04:38,050 to the ItemModel as arguments. 116 00:04:38,050 --> 00:04:40,490 In the last section we didn't quite have this. 117 00:04:40,490 --> 00:04:42,990 We were only passing in the price, 118 00:04:42,990 --> 00:04:44,920 so this just makes everything a little bit nicer, 119 00:04:44,920 --> 00:04:46,480 and we're doing the same thing down here 120 00:04:46,480 --> 00:04:48,833 as well like there. 121 00:04:50,250 --> 00:04:53,640 The same thing applies to the store. 122 00:04:53,640 --> 00:04:54,473 Sorry, not the store. 123 00:04:54,473 --> 00:04:57,880 The store only has one name, 124 00:04:57,880 --> 00:04:59,790 but the same thing can be applied here 125 00:04:59,790 --> 00:05:00,623 in the UserModel. 126 00:05:00,623 --> 00:05:02,830 As you can see we are passing data username 127 00:05:02,830 --> 00:05:03,970 and data password. 128 00:05:03,970 --> 00:05:07,770 Instead we can just do data like that. 129 00:05:07,770 --> 00:05:09,320 That means exactly the same thing, 130 00:05:09,320 --> 00:05:13,570 just passes username as a named argument 131 00:05:13,570 --> 00:05:15,740 and password as another named argument 132 00:05:15,740 --> 00:05:18,360 into the UserModel, and the values are the ones 133 00:05:18,360 --> 00:05:19,193 that are coming from the parser. 134 00:05:19,193 --> 00:05:21,230 So it just makes things a little bit nicer, 135 00:05:21,230 --> 00:05:23,080 and that's why we're using that here. 136 00:05:24,010 --> 00:05:27,030 Now, in the item resource 137 00:05:28,120 --> 00:05:32,983 we've got this list and map of the json. 138 00:05:34,700 --> 00:05:38,200 What we want to do instead is return a list comprehension 139 00:05:38,200 --> 00:05:40,880 just because list comprehensions are generally 140 00:05:40,880 --> 00:05:43,240 a little bit faster, a little bit more readable 141 00:05:43,240 --> 00:05:44,720 for Python developers. 142 00:05:44,720 --> 00:05:48,220 So I know that we used list and map 143 00:05:48,220 --> 00:05:50,170 over the last few section, 144 00:05:50,170 --> 00:05:51,820 but not we're going to turn over 145 00:05:51,820 --> 00:05:53,640 to list comprehensions just because 146 00:05:53,640 --> 00:05:55,400 they're a bit more Pythonic. 147 00:05:55,400 --> 00:05:56,500 So, all we have to do 148 00:05:56,500 --> 00:05:57,910 to make this into a list comprehension 149 00:05:57,910 --> 00:06:01,920 is say X for X in. 150 00:06:01,920 --> 00:06:02,753 Sorry, x.json 151 00:06:05,520 --> 00:06:08,633 for X in ItemModel query all, 152 00:06:11,212 --> 00:06:12,680 and that's it. 153 00:06:12,680 --> 00:06:14,320 Let's take that away. 154 00:06:14,320 --> 00:06:15,980 So now we're returning the json 155 00:06:17,160 --> 00:06:20,953 of X for X in all the ItemModels 156 00:06:20,953 --> 00:06:21,830 that we query, 157 00:06:21,830 --> 00:06:23,490 and if we want we can of course rename this 158 00:06:23,490 --> 00:06:24,690 to something like item 159 00:06:24,690 --> 00:06:28,010 or whatever else you want to name your variable, 160 00:06:28,010 --> 00:06:29,910 but this is just there for simplicity. 161 00:06:30,950 --> 00:06:32,040 In the store we're gonna do the same thing. 162 00:06:32,040 --> 00:06:35,467 We're gonna go down here and do x.json 163 00:06:38,614 --> 00:06:40,160 for X in that. 164 00:06:42,980 --> 00:06:45,560 Again, just makes it a little bit more readable I feel, 165 00:06:45,560 --> 00:06:47,153 and it's a bit more Pythonic. 166 00:06:49,330 --> 00:06:54,330 Okay, in these store list and item lists 167 00:06:54,570 --> 00:06:57,090 we're also going to modify this slightly. 168 00:06:57,090 --> 00:06:59,850 So instead of accessing the query object 169 00:06:59,850 --> 00:07:04,850 of the store, we are going to do StoreModel.find_all. 170 00:07:05,300 --> 00:07:07,140 Now there's a reason for this, 171 00:07:07,140 --> 00:07:09,600 which is I'm not a big fan 172 00:07:09,600 --> 00:07:11,720 of accessing the query object 173 00:07:11,720 --> 00:07:13,920 from within the resource. 174 00:07:13,920 --> 00:07:15,110 I get the feeling that 175 00:07:15,110 --> 00:07:19,470 it's a bit nicer if we can have a method 176 00:07:19,470 --> 00:07:23,880 that encapsulates accessing the query of a model, 177 00:07:23,880 --> 00:07:27,710 and we don't make the resource access that itself. 178 00:07:27,710 --> 00:07:32,120 The reason for that is, if you access the query object 179 00:07:32,120 --> 00:07:34,770 in the resource, you could essentially 180 00:07:34,770 --> 00:07:39,770 just in many occasions not use the model at all. 181 00:07:40,140 --> 00:07:42,730 You could just access query here, 182 00:07:42,730 --> 00:07:45,550 and, for example, here instead of find by name 183 00:07:45,550 --> 00:07:47,430 you could just use the query object, 184 00:07:47,430 --> 00:07:48,770 and you can do that. 185 00:07:48,770 --> 00:07:50,100 That's totally find, 186 00:07:50,100 --> 00:07:52,350 but it starts making the resource 187 00:07:52,350 --> 00:07:53,570 a bit too heavy. 188 00:07:53,570 --> 00:07:56,280 It starts making the resource interact 189 00:07:56,280 --> 00:07:58,220 with the database if you wish 190 00:07:58,220 --> 00:07:59,543 by doing the querying, 191 00:08:00,390 --> 00:08:02,630 and I think that can get a little bit complicated, 192 00:08:02,630 --> 00:08:04,210 and it was fine down here 193 00:08:04,210 --> 00:08:08,180 to some extent because it was only StoreModel.query.all, 194 00:08:08,180 --> 00:08:10,920 but moving forward we wanna make this a little bit better. 195 00:08:10,920 --> 00:08:14,450 So we are going to create this find_all function, 196 00:08:14,450 --> 00:08:16,649 sorry, method in the StoreModel, 197 00:08:16,649 --> 00:08:20,120 and we are going to use that instead. 198 00:08:20,120 --> 00:08:22,783 So instead of here, we're gonna do classmethod, 199 00:08:23,789 --> 00:08:26,890 find_all, and this is just going to return 200 00:08:26,890 --> 00:08:28,483 cls.query.all, 201 00:08:30,270 --> 00:08:31,860 and that's it, 202 00:08:31,860 --> 00:08:33,320 and of course we don't need a semi colon there. 203 00:08:33,320 --> 00:08:36,050 Sorry, I've been doing a lot of JavaScript recently. 204 00:08:36,050 --> 00:08:38,660 So that's not so good. 205 00:08:38,660 --> 00:08:40,320 Then we have a find_all for the store. 206 00:08:40,320 --> 00:08:43,320 We're gonna add it into the item as well, 207 00:08:43,320 --> 00:08:44,400 and we're going to do the same thing 208 00:08:44,400 --> 00:08:45,390 in the item resource. 209 00:08:45,390 --> 00:08:47,700 So now we've added a find_all method 210 00:08:47,700 --> 00:08:48,650 in the ItemModel. 211 00:08:48,650 --> 00:08:50,410 We're gonna go to the item resource, 212 00:08:50,410 --> 00:08:53,493 and instead of query.all we're gonna do find_all. 213 00:08:54,870 --> 00:08:55,703 That's it. 214 00:08:55,703 --> 00:08:57,200 Remember to save the files by the way. 215 00:08:57,200 --> 00:08:59,753 I tend to forget sometimes, 216 00:09:01,930 --> 00:09:04,810 and that's pretty close to it. 217 00:09:04,810 --> 00:09:06,970 We just wanna add one more thing here 218 00:09:06,970 --> 00:09:10,630 in the json method of the item and the store. 219 00:09:10,630 --> 00:09:13,363 We are going to add just a store_id here, 220 00:09:16,125 --> 00:09:18,043 and it's going to be self.store_id, 221 00:09:20,920 --> 00:09:22,800 and we're also going to add the id 222 00:09:22,800 --> 00:09:26,670 of the item just so we get a bit more information. 223 00:09:26,670 --> 00:09:29,720 Okay, now because this is getting a bit long, 224 00:09:29,720 --> 00:09:32,970 and we don't need that. 225 00:09:32,970 --> 00:09:34,150 Because this is getting a little bit long, 226 00:09:34,150 --> 00:09:35,840 we're just gonna break it down into lines 227 00:09:35,840 --> 00:09:39,973 to make it a bit nicer like that, 228 00:09:41,100 --> 00:09:44,083 and of course we do need the quotation marks there. 229 00:09:44,930 --> 00:09:46,710 Okay, just added two more properties, 230 00:09:46,710 --> 00:09:48,750 id and store_id into the item 231 00:09:48,750 --> 00:09:51,250 so that when we get it with our API, 232 00:09:51,250 --> 00:09:54,910 it's a bit easier to understand what's going on. 233 00:09:54,910 --> 00:09:57,140 In the store model we're gonna do the same, 234 00:09:57,140 --> 00:10:00,700 gonna break it down into lines here, 235 00:10:00,700 --> 00:10:03,570 and we are going to add the id 236 00:10:07,240 --> 00:10:08,260 just like that. 237 00:10:08,260 --> 00:10:12,390 Now the store is returning the id, name, and items 238 00:10:12,390 --> 00:10:14,870 so that we get the id of the store 239 00:10:14,870 --> 00:10:17,503 when we retrieve it using our API. 240 00:10:19,250 --> 00:10:21,150 Now the last thing that you may see 241 00:10:21,150 --> 00:10:24,290 in this project that we've not look at before 242 00:10:24,290 --> 00:10:26,833 is this requirements.txt file. 243 00:10:27,770 --> 00:10:30,750 The requirements.txt file just contains 244 00:10:30,750 --> 00:10:32,470 the three dependencies of our project, 245 00:10:32,470 --> 00:10:36,820 Flask-JWT, FlaskRESTful, and Flask_SQLAlchemy. 246 00:10:36,820 --> 00:10:40,010 We're putting them here so that we can easily remember 247 00:10:40,010 --> 00:10:42,690 and instal them into our virtual environments 248 00:10:42,690 --> 00:10:45,110 when we share this code with someone else 249 00:10:45,110 --> 00:10:47,640 or when we go to a different computer 250 00:10:47,640 --> 00:10:49,180 and want to run this code, 251 00:10:49,180 --> 00:10:51,773 we'll very quickly know what we have to instal. 252 00:10:52,810 --> 00:10:53,890 So that is here. 253 00:10:53,890 --> 00:10:56,280 Requirements.txt is a very common name 254 00:10:56,280 --> 00:10:57,113 for this file. 255 00:10:57,113 --> 00:10:58,640 So make sure to call it that 256 00:10:58,640 --> 00:11:00,933 as that's the convention in Python code. 257 00:11:02,370 --> 00:11:03,203 So that's it for this video. 258 00:11:03,203 --> 00:11:06,100 I'm sorry it's been a little bit of a longer one, 259 00:11:06,100 --> 00:11:09,640 but I just wanted to quickly cover a few changes 260 00:11:09,640 --> 00:11:11,880 from the very last section of the course 261 00:11:11,880 --> 00:11:14,770 into this section because a couple of things 262 00:11:14,770 --> 00:11:16,760 have changed just to make things a bit nice, 263 00:11:16,760 --> 00:11:18,210 and now we are going to move 264 00:11:18,210 --> 00:11:22,870 into implementing Flask-JWT-Extended. 265 00:11:22,870 --> 00:11:25,370 So with that said, I'll see you on the next video.