1 1 00:00:01,130 --> 00:00:02,390 Hi and welcome back. 2 2 00:00:02,390 --> 00:00:04,680 In this video we're going to continue 3 3 00:00:04,680 --> 00:00:06,790 using stores in our application 4 4 00:00:06,790 --> 00:00:08,650 and we're gonna remove the ability 5 5 00:00:08,650 --> 00:00:11,680 for users to create items. 6 6 00:00:11,680 --> 00:00:13,930 We're going to start in app dot PY. 7 7 00:00:13,930 --> 00:00:17,590 We're just gonna delete the item blueprint from here. 8 8 00:00:17,590 --> 00:00:18,670 Why's that? 9 9 00:00:18,670 --> 00:00:21,430 Well, items are gonna be used internally now. 10 10 00:00:21,430 --> 00:00:24,420 Users are not going to be creating items 11 11 00:00:24,420 --> 00:00:26,550 or retrieving items, or anything like that, 12 12 00:00:26,550 --> 00:00:28,820 because we're gonna create them 13 13 00:00:28,820 --> 00:00:30,420 when we create an alert 14 14 00:00:30,420 --> 00:00:33,750 and we're gonna use the data stored in the store models 15 15 00:00:33,750 --> 00:00:37,150 instead of having the user creating items. 16 16 00:00:37,150 --> 00:00:38,853 So we no longer need them there. 17 17 00:00:40,260 --> 00:00:42,170 Now in the alert form, 18 18 00:00:42,170 --> 00:00:43,400 where we create a new alert, 19 19 00:00:43,400 --> 00:00:45,650 we're no longer going to take an item ID. 20 20 00:00:45,650 --> 00:00:46,910 We know this was silly 21 21 00:00:46,910 --> 00:00:50,170 because the user was never gonna know the item ID. 22 22 00:00:50,170 --> 00:00:52,773 Instead we're gonna take in an item URL. 23 23 00:00:53,760 --> 00:00:57,210 And the reason for that is we're gonna use the item URL 24 24 00:00:57,210 --> 00:01:00,200 to find the related store in our database 25 25 00:01:00,200 --> 00:01:03,590 and with that store, we're going to find the URL, 26 26 00:01:03,590 --> 00:01:06,573 sorry, the tag name, and the query. 27 27 00:01:09,560 --> 00:01:11,500 Now if we take this away 28 28 00:01:11,500 --> 00:01:16,180 then we do have to go into our alert views 29 29 00:01:16,180 --> 00:01:18,610 and instead of taking in an item ID, 30 30 00:01:18,610 --> 00:01:20,210 we're gonna take in an item URL. 31 31 00:01:21,130 --> 00:01:23,920 And the value of that is item URL in the form 32 32 00:01:23,920 --> 00:01:27,740 and the alert is now going to have to find 33 33 00:01:28,880 --> 00:01:30,530 the item in the database. 34 34 00:01:30,530 --> 00:01:32,190 So, how's it gonna go? 35 35 00:01:32,190 --> 00:01:34,860 We're gonna say that the store is going to be 36 36 00:01:34,860 --> 00:01:37,570 store dot find by URL 37 37 00:01:37,570 --> 00:01:39,420 and we're gonna give it the item URL. 38 38 00:01:40,270 --> 00:01:44,020 And then we're gonna create an item for that. 39 39 00:01:44,020 --> 00:01:47,860 So the item is gonna have the item URL that we want 40 40 00:01:47,860 --> 00:01:51,003 and the store tag name and the store query. 41 41 00:01:51,950 --> 00:01:54,830 Then we're gonna save that item to MongoDB. 42 42 00:01:54,830 --> 00:01:57,210 And then the alert we create is gonna have the 43 43 00:01:57,210 --> 00:02:00,600 items dot underscore ID property. 44 44 00:02:00,600 --> 00:02:02,670 Now PyCharm is gonna complain when you do this. 45 45 00:02:02,670 --> 00:02:05,020 It says access to a protected member underscore ID 46 46 00:02:05,020 --> 00:02:06,010 of a class. 47 47 00:02:06,010 --> 00:02:08,060 But that is okay in Python. 48 48 00:02:08,060 --> 00:02:09,320 This is just a warning. 49 49 00:02:09,320 --> 00:02:10,340 It's something you can do. 50 50 00:02:10,340 --> 00:02:11,240 It's not a problem. 51 51 00:02:11,240 --> 00:02:12,593 It's not anti-Pythonic. 52 52 00:02:13,560 --> 00:02:16,120 The main reason why we have private variables 53 53 00:02:16,120 --> 00:02:17,650 or things that we signal as private 54 54 00:02:17,650 --> 00:02:19,140 with the underscore in front 55 55 00:02:19,140 --> 00:02:22,580 is because we don't want other people to change them. 56 56 00:02:22,580 --> 00:02:23,730 And we're not changing it here. 57 57 00:02:23,730 --> 00:02:25,220 We're just using it and reading it. 58 58 00:02:25,220 --> 00:02:26,173 So this is fine. 59 59 00:02:27,520 --> 00:02:29,720 We don't need this JSON import. 60 60 00:02:29,720 --> 00:02:31,300 Not sure why that's there, 61 61 00:02:31,300 --> 00:02:35,543 but we do need to do the other imports. 62 62 00:02:40,720 --> 00:02:41,553 Like that. 63 63 00:02:42,420 --> 00:02:44,190 Now again, this warning will stay there, 64 64 00:02:44,190 --> 00:02:46,360 but that's okay. 65 65 00:02:46,360 --> 00:02:47,800 What else do we not need? 66 66 00:02:47,800 --> 00:02:50,150 Well, we don't actually need any 67 67 00:02:50,150 --> 00:02:52,080 of the item templates anymore. 68 68 00:02:52,080 --> 00:02:54,810 Because we're just not gonna use them. 69 69 00:02:54,810 --> 00:02:57,290 Our user is not going to be dealing with this stuff 70 70 00:02:57,290 --> 00:02:59,700 so we can delete that entirely 71 71 00:02:59,700 --> 00:03:03,040 and we can also delete the item views. 72 72 00:03:03,040 --> 00:03:03,873 So that's it. 73 73 00:03:03,873 --> 00:03:04,740 They're gone. 74 74 00:03:04,740 --> 00:03:07,670 And this is one of the best feelings in programming, 75 75 00:03:07,670 --> 00:03:10,060 which is when you get delete a bunch of code. 76 76 00:03:10,060 --> 00:03:11,550 Code you don't need anymore 77 77 00:03:11,550 --> 00:03:13,510 because you've got a better way, 78 78 00:03:13,510 --> 00:03:16,740 or at least a simpler way of doing things. 79 79 00:03:16,740 --> 00:03:20,330 We've added a little bit of complexity for ourselves, 80 80 00:03:20,330 --> 00:03:24,290 but in exchange we've made it much easier for users. 81 81 00:03:24,290 --> 00:03:27,400 Of course, we do need a way to add stores to our database, 82 82 00:03:27,400 --> 00:03:28,653 so we will be doing that. 83 83 00:03:29,610 --> 00:03:32,700 But now what we've done is we have made the changes 84 84 00:03:32,700 --> 00:03:36,550 that we needed to make in order to stop using items 85 85 00:03:36,550 --> 00:03:37,920 and it's stopped our users 86 86 00:03:37,920 --> 00:03:39,650 having to give us item information 87 87 00:03:39,650 --> 00:03:42,230 and instead they just give us an item URL. 88 88 00:03:42,230 --> 00:03:44,920 We then find the store with that URL 89 89 00:03:44,920 --> 00:03:47,620 and then we create an item object internally 90 90 00:03:47,620 --> 00:03:50,060 only for ourselves, only for our application 91 91 00:03:50,060 --> 00:03:52,310 that uses the item URL they want 92 92 00:03:52,310 --> 00:03:55,260 and the store, tag name, and query. 93 93 00:03:55,260 --> 00:03:57,670 If they give us something like 94 94 00:03:57,670 --> 00:04:01,240 HTTPS www dot johnlewis dot com 95 95 00:04:01,240 --> 00:04:04,140 slash item slash bla dot HTML 96 96 00:04:04,140 --> 00:04:06,110 then we're going to find a store 97 97 00:04:06,110 --> 00:04:08,583 that matches this URL prefix, 98 98 00:04:09,600 --> 00:04:11,500 which if we add it to our database 99 99 00:04:11,500 --> 00:04:13,820 will give us an actual store 100 100 00:04:13,820 --> 00:04:16,580 and that store will have the information needed 101 101 00:04:16,580 --> 00:04:18,920 to extract information from pages 102 102 00:04:18,920 --> 00:04:21,070 that use this URL structure. 103 103 00:04:21,070 --> 00:04:23,350 So it's gonna have a tag name of P 104 104 00:04:23,350 --> 00:04:27,820 and a query of class price price dash dash large. 105 105 00:04:27,820 --> 00:04:30,310 With that information, we will then be able 106 106 00:04:30,310 --> 00:04:33,683 to retrieve the item price when we come to it. 107 107 00:04:34,790 --> 00:04:37,840 All right, so we're going to be testing this out, 108 108 00:04:37,840 --> 00:04:39,950 we're gonna do that, in the next video. 109 109 00:04:39,950 --> 00:04:41,260 Thank you for joining me. 110 110 00:04:41,260 --> 00:04:42,210 I'll see you there.