1 00:00:05,510 --> 00:00:06,960 Yo what's up everyone. 2 00:00:06,970 --> 00:00:09,590 Mark Price here at Dove slopes dot com. 3 00:00:09,610 --> 00:00:11,620 And let's continue building our app here. 4 00:00:11,620 --> 00:00:12,880 We're making great progress. 5 00:00:12,880 --> 00:00:19,390 We want to do next is actually have this product screen show and we want to get our collection view 6 00:00:19,390 --> 00:00:21,730 all configured etc. etc.. 7 00:00:21,730 --> 00:00:29,080 So first things is we need to make sure we have an identifier on our Segway So click your Segway and 8 00:00:29,170 --> 00:00:31,080 then add the attributes and Specter over here. 9 00:00:31,180 --> 00:00:36,220 Set an identifier and I like to just set this to The View Controller that we are going to which I believe 10 00:00:36,220 --> 00:00:39,970 is the product B C 11 00:00:42,440 --> 00:00:42,980 category. 12 00:00:43,040 --> 00:00:44,480 So we haven't created it yet. 13 00:00:44,480 --> 00:00:47,000 Well we should do that and then we'll set the identifier. 14 00:00:47,000 --> 00:00:54,350 So in your controller folder Let's go to new file Cocco touch class and instead of view collection. 15 00:00:54,350 --> 00:01:06,610 So we will say you view controller and we will call this product B C press Enter create. 16 00:01:06,900 --> 00:01:07,180 OK. 17 00:01:07,200 --> 00:01:09,220 Now we'll go back to the main storyboard here. 18 00:01:09,360 --> 00:01:15,890 We'll select our view controller will change its class to the products we see wonderful. 19 00:01:15,960 --> 00:01:23,960 And then on the segue here now we can set the identifier to products Visi save it there. 20 00:01:24,170 --> 00:01:24,430 OK. 21 00:01:24,450 --> 00:01:26,850 So the Segway identifiers in there. 22 00:01:26,850 --> 00:01:33,690 Let's go back to our categories Visi and what we want to do is when a category is selected like tapped 23 00:01:33,780 --> 00:01:39,030 we want to show another view controllers are really all we're doing here is presenting a Segway and 24 00:01:39,030 --> 00:01:43,950 then passing that appropriate data into the other view controller that we're going to be going to how 25 00:01:43,950 --> 00:01:44,590 do we do that. 26 00:01:44,590 --> 00:01:53,100 Well the Table View delegate has a really cool function called did select row an index path. 27 00:01:53,100 --> 00:01:59,000 One thing that's really important is that you don't accidentally click did de-select so did de-select. 28 00:01:59,110 --> 00:02:03,930 Ok that's when they've selected and taken their finger off a lot of new developers actually enter this 29 00:02:03,930 --> 00:02:07,020 in and then the table view is not working correctly when you're tapping it. 30 00:02:07,020 --> 00:02:11,330 So we did select a row index path. 31 00:02:11,550 --> 00:02:12,150 OK. 32 00:02:12,600 --> 00:02:17,160 So we're going to tap roll is going to tell us which row is tapped and then we can build out some logic 33 00:02:17,160 --> 00:02:17,580 here. 34 00:02:17,610 --> 00:02:18,690 No big deal. 35 00:02:18,690 --> 00:02:22,360 So first things first is let's grab the appropriate category that was tapped. 36 00:02:22,470 --> 00:02:37,680 So let category category equals data service get categories and data service get categories and we're 37 00:02:37,680 --> 00:02:41,140 going to say Index path dot row. 38 00:02:41,670 --> 00:02:42,120 OK. 39 00:02:42,210 --> 00:02:45,790 So we're just grabbing the category. 40 00:02:45,900 --> 00:02:50,320 You know I think it's good category. 41 00:02:50,670 --> 00:02:57,650 Now that's correct datasource get category it's trippin out it's just trippin out here. 42 00:02:57,690 --> 00:03:04,300 I'm going to copy what we have up here because this one is trippin out tax code and it's trippin. 43 00:03:04,540 --> 00:03:05,220 All right. 44 00:03:05,470 --> 00:03:06,670 So there's our category. 45 00:03:06,910 --> 00:03:07,800 Wonderful. 46 00:03:07,810 --> 00:03:14,080 And then what we want to do is say perform a segue like so with identifier where we know it's the products 47 00:03:14,100 --> 00:03:18,150 Visi Segway and the sender basically will object. 48 00:03:18,160 --> 00:03:19,280 We want to pass this. 49 00:03:19,300 --> 00:03:22,030 So when I prepare for SEGUI is called We have data available to us. 50 00:03:22,030 --> 00:03:28,180 And this is where we pass in that category so we're passing in data here into our perform Segway. 51 00:03:28,360 --> 00:03:35,740 So then when prepare for Segway is called We can then pass that over into our products and then sell 52 00:03:35,740 --> 00:03:38,920 it to the prepare for Segway function like so. 53 00:03:38,940 --> 00:03:50,430 And you've done this before if let products be C equals Segway destination as products B. 54 00:03:50,440 --> 00:03:55,530 So we're describing the destination View Controller and we're casting it into the appropriate view controller. 55 00:03:55,710 --> 00:03:56,270 Okay. 56 00:03:56,590 --> 00:04:02,740 And then what we'll do is we will set the category on that controller but we don't have any variables 57 00:04:02,740 --> 00:04:03,520 or anything for that yet. 58 00:04:03,520 --> 00:04:09,310 So what I want to do is go to my products Visi get rid of this comment here. 59 00:04:09,370 --> 00:04:16,300 And what I want to do is see what it did receive memory warning is its great function here called initialized 60 00:04:16,300 --> 00:04:17,160 products. 61 00:04:17,460 --> 00:04:18,130 Okay. 62 00:04:18,670 --> 00:04:26,170 And then what we'll do is we'll pass in a room what do we want to call this exactly initialized products 63 00:04:26,500 --> 00:04:32,500 for like a category title like will pass in a title or just pass and the whole category just thinking 64 00:04:32,500 --> 00:04:33,420 aloud here. 65 00:04:33,680 --> 00:04:34,470 OK. 66 00:04:34,960 --> 00:04:36,410 Products category. 67 00:04:36,970 --> 00:04:38,010 Wonderful. 68 00:04:38,050 --> 00:04:43,930 And then what we'll do here is we'll actually store a list of products so same must be done before private 69 00:04:43,930 --> 00:04:44,840 set. 70 00:04:45,400 --> 00:04:54,220 And then it's if I can type public var and this one is going to be called products. 71 00:04:54,240 --> 00:04:54,790 All right. 72 00:04:54,970 --> 00:05:05,740 And it's going to be an empty array type product like so if you're wondering why we're making this an 73 00:05:05,740 --> 00:05:06,550 empty array. 74 00:05:06,660 --> 00:05:14,370 And the reason is let's say that we the data hasn't loaded yet you're getting it from the internet somewhere. 75 00:05:14,530 --> 00:05:17,450 Well you want an empty array to base your collection view off of. 76 00:05:17,470 --> 00:05:19,570 Otherwise it will just nail your collection. 77 00:05:19,570 --> 00:05:24,740 You would look for an item and your app would crash so that's why we're creating an empty array here. 78 00:05:25,090 --> 00:05:25,640 OK. 79 00:05:25,870 --> 00:05:30,880 And what we're going to do here is simply use the function that we already built in our data service 80 00:05:30,880 --> 00:05:34,450 to get the appropriate product for this category that we are passing in. 81 00:05:34,720 --> 00:05:40,660 OK so what we're going to do is we're going to say self X I don't need to say self-heating to say products 82 00:05:40,840 --> 00:05:44,070 equals data service. 83 00:05:44,640 --> 00:05:51,440 And since get products for category title we're going to say category title. 84 00:05:51,610 --> 00:05:55,840 So it's going to happen as our products array is going to be populated with products and we're just 85 00:05:55,840 --> 00:06:01,520 passing in the title that was passed in the categories we see here to the products AVC. 86 00:06:01,620 --> 00:06:08,790 And so now this initialized products function we can actually call from right here so we can say products 87 00:06:08,790 --> 00:06:20,610 AVC dot initialized products and we can pass in the sender as a product or category that we go like 88 00:06:20,610 --> 00:06:25,360 so. 89 00:06:25,400 --> 00:06:29,750 So what we're doing here is we're grabbing the products Visi and then we're just calling that initialized 90 00:06:29,750 --> 00:06:31,640 products function that we just created. 91 00:06:31,640 --> 00:06:37,270 Sender you're like what descender center is just the category that we passed and so remember up here 92 00:06:37,280 --> 00:06:41,570 when ended Slik ROA index path we passed in the category to the sender. 93 00:06:41,570 --> 00:06:46,520 All we're doing here is grabbing the sender because when you pass it in the parameter type is any like 94 00:06:46,550 --> 00:06:47,650 any object. 95 00:06:47,690 --> 00:06:52,940 And so we have to specify that this is a category so sender as category and why am I force in wrapping 96 00:06:52,940 --> 00:06:59,600 it because I know for a fact that it is a category because I just set it right there because you can 97 00:06:59,600 --> 00:07:01,820 be sure that this is going to cast correctly. 98 00:07:01,910 --> 00:07:06,750 So products VCDs initialized products sender as category. 99 00:07:06,770 --> 00:07:07,240 Okay. 100 00:07:07,250 --> 00:07:12,880 And one thing that we probably want to do here is create an assertion so build time. 101 00:07:12,920 --> 00:07:17,020 We know that this is working correctly and then I'll feel more comfortable using that force unwrap. 102 00:07:17,150 --> 00:07:18,390 So let's do that now. 103 00:07:19,160 --> 00:07:30,580 But we're going to say assert that sender as with a question mark category is not equal to nil. 104 00:07:30,910 --> 00:07:31,680 Okay. 105 00:07:31,700 --> 00:07:36,500 And this assertion is good because what it is going to do is at build time. 106 00:07:36,530 --> 00:07:38,050 This is only for build time. 107 00:07:38,090 --> 00:07:40,030 Develop motets not for production. 108 00:07:40,270 --> 00:07:44,930 What's going to happen is this assertion is going to be called and it's going to say it absolutely must 109 00:07:44,930 --> 00:07:48,650 be of type category when we cast it and if it's not it's going to crash your app at build time. 110 00:07:48,680 --> 00:07:52,550 As a developer so as a developer you're going through you're building your project and then you go in 111 00:07:52,550 --> 00:07:56,630 here and then your app crashes you know that you need to fix it we're forcing a crash here if it's not 112 00:07:56,630 --> 00:07:56,990 working. 113 00:07:56,990 --> 00:07:59,410 So at runtime it will definitely work. 114 00:07:59,560 --> 00:08:02,990 OK this is just a layer of protection in your development that will help you out. 115 00:08:02,990 --> 00:08:06,790 Now you maybe you think it will mark why didn't you do a guard statement in the casting. 116 00:08:06,790 --> 00:08:07,100 OK. 117 00:08:07,100 --> 00:08:10,750 Or why didn't you do and if let if let sender ask category. 118 00:08:10,760 --> 00:08:16,740 Well the reason I didn't do an if or guard is because my application requires this to be a category. 119 00:08:16,760 --> 00:08:18,050 It's not chance. 120 00:08:18,050 --> 00:08:18,640 OK. 121 00:08:18,860 --> 00:08:22,150 It's not user base where it might be a category it might be something else. 122 00:08:22,160 --> 00:08:25,470 Ok if that was the case we would use the guard or an IF let. 123 00:08:25,520 --> 00:08:30,680 But since my app requires that this is a category when we cast it it makes more sense to use an assertion. 124 00:08:30,740 --> 00:08:31,870 So build time. 125 00:08:32,000 --> 00:08:35,030 If it's not working it crashes our app which is what we want. 126 00:08:35,140 --> 00:08:36,380 OK we can guarantee it no. 127 00:08:36,380 --> 00:08:44,140 So I feel a lot better about force unwrapping the this or forecasting this here so we're initialising 128 00:08:44,150 --> 00:08:46,910 the products center as category this is great. 129 00:08:46,910 --> 00:08:53,630 And then in the products you see it's going to go ahead and set the products to the products that we 130 00:08:54,080 --> 00:08:55,940 have here in our data service. 131 00:08:55,940 --> 00:08:59,870 So the next thing we need to do is get our collection of view actually working. 132 00:08:59,870 --> 00:09:04,970 So let's implement a couple of protocols put a comma after you view controller and we're going to use 133 00:09:05,010 --> 00:09:14,190 a collection of view delegate and UI collection view data source like we've done before. 134 00:09:14,190 --> 00:09:19,640 And of course we need the outlet for our collection of views at Iby outlet weak var and we're going 135 00:09:19,640 --> 00:09:25,540 to say products collection of type you collection view. 136 00:09:26,070 --> 00:09:26,700 OK. 137 00:09:27,020 --> 00:09:28,540 And we're putting the exclamation there at the end. 138 00:09:28,550 --> 00:09:31,180 Meaning it's an implicitly unwrapped optional. 139 00:09:31,190 --> 00:09:34,730 And it's saying hey you haven't implemented the function so click the red button up here. 140 00:09:34,740 --> 00:09:35,930 Do you want to add protocol stubs. 141 00:09:35,960 --> 00:09:37,330 Absolutely. 142 00:09:37,340 --> 00:09:44,760 So command X protocol stubs will put them where they actually belong down here get to get rid of the 143 00:09:44,760 --> 00:09:52,220 available nonsense and this year the code and get rid of that their income and what we'll do here you 144 00:09:52,280 --> 00:10:00,840 did load is we will say products collection datasource equals self and products collection delegate 145 00:10:01,250 --> 00:10:09,120 equals self OK we are saying that hey this collection of view is going to be the delegate and implement 146 00:10:09,120 --> 00:10:14,390 the protocols the appropriate protocols to get this working OK. 147 00:10:14,540 --> 00:10:16,860 And so a number of items in section. 148 00:10:16,860 --> 00:10:18,180 Now there are multiple. 149 00:10:18,210 --> 00:10:21,440 You could have an app with multiple sections a collection view or table view. 150 00:10:21,450 --> 00:10:22,790 In our case we only have one. 151 00:10:22,950 --> 00:10:27,420 So what I'm going to do is just simply return products that count. 152 00:10:27,420 --> 00:10:34,840 Otherwise what you might have done is you might have said if Section equals 1 then you return three 153 00:10:35,010 --> 00:10:35,620 you know. 154 00:10:35,670 --> 00:10:36,290 Or. 155 00:10:36,600 --> 00:10:39,530 Well you know whatever number it is or some other collection. 156 00:10:39,690 --> 00:10:41,700 Else if Section equals to return this money. 157 00:10:41,700 --> 00:10:48,060 But in our case again we only have one section so we're going to return products that count and then 158 00:10:48,060 --> 00:10:49,530 sell for item index path. 159 00:10:49,530 --> 00:10:52,540 This is very similar to what we've done with the table view. 160 00:10:52,980 --> 00:11:01,610 Okay we're simply going to say if let sell equals collection view dequeue reusable sell. 161 00:11:01,650 --> 00:11:05,660 And this one's going to be the product sell. 162 00:11:05,670 --> 00:11:09,900 I think that's what we called it or what we will call it if we haven't done it yet for index path and 163 00:11:09,900 --> 00:11:14,790 in this case it's looking for the index path that's being passed in right here from the function. 164 00:11:14,790 --> 00:11:17,080 So there's our cell if let's sell. 165 00:11:17,160 --> 00:11:21,880 And then what we want to do in the cell is just passing the data that we're going to need. 166 00:11:22,080 --> 00:11:27,620 And so let's look at our cell product cell and we don't have a way to update the data here so let's 167 00:11:27,620 --> 00:11:29,300 create our function to do that. 168 00:11:29,300 --> 00:11:35,600 So function update views and we're going to pass in a product. 169 00:11:35,600 --> 00:11:38,750 We've done this before with the table view very similar. 170 00:11:38,750 --> 00:11:46,520 And what we'll say is we will say product image image equals image named. 171 00:11:46,790 --> 00:11:57,680 And this is going to be product image name and then product title text equals product title and product 172 00:11:57,710 --> 00:11:58,440 price. 173 00:11:58,580 --> 00:12:01,890 Text equals product price. 174 00:12:01,940 --> 00:12:07,760 So all we're doing here is every time a collection view cell is created or Decoud we're going to pass 175 00:12:07,760 --> 00:12:10,070 in the appropriate product and update the view. 176 00:12:10,070 --> 00:12:14,790 So it's showing the correct data and this is important because of views on a collection of cell and 177 00:12:15,480 --> 00:12:17,480 collection of you and a table of you are recycled. 178 00:12:17,540 --> 00:12:19,650 So we have to continually update the views. 179 00:12:19,830 --> 00:12:20,570 OK. 180 00:12:20,930 --> 00:12:22,190 So that looks good there. 181 00:12:22,190 --> 00:12:27,890 So back in our products we see what we can do now is we can grab the appropriate product and then pass 182 00:12:27,890 --> 00:12:35,080 it into the cell so we can say let product equals products index path dot row. 183 00:12:35,180 --> 00:12:40,190 Okay we're grabbing the appropriate Roe for the products and we're storing for the product and we're 184 00:12:40,190 --> 00:12:46,430 storing it here in this product constant and then sell that update views. 185 00:12:46,960 --> 00:12:48,490 We forgot to cast it. 186 00:12:48,560 --> 00:12:56,880 So let's cast that now so as it were in safe product sale never go now it knows it's a product sell. 187 00:12:56,890 --> 00:13:04,010 Once I sell that update views and we'll pass in the product and then we will return the cell as the 188 00:13:04,010 --> 00:13:05,610 function requires. 189 00:13:05,630 --> 00:13:10,550 Otherwise if this didn't cast appropriately like when we converted the cell it didn't it wasn't a product 190 00:13:10,550 --> 00:13:14,450 cell which could happen if you had like a head or cell or some of you had multiple different types of 191 00:13:14,450 --> 00:13:19,100 cells for a single collection which you can maybe you have one cell that looks one way for a certain 192 00:13:19,100 --> 00:13:22,710 type of data and another cell it looks the other way you might have two collection B cells. 193 00:13:22,820 --> 00:13:28,910 In our case we only have one eye but we still need this statement here or rather you don't even need 194 00:13:28,910 --> 00:13:29,600 an else statement. 195 00:13:29,590 --> 00:13:36,900 You could just say return and then we could say product cell because it would never get here if you 196 00:13:36,950 --> 00:13:39,070 made it through this portion here. 197 00:13:39,490 --> 00:13:39,790 OK. 198 00:13:39,800 --> 00:13:44,750 So great we're we are creating a cell or two cuing it we're passing in the appropriate product so it 199 00:13:44,840 --> 00:13:49,440 updates the data and then returning that cell that looks fantastic. 200 00:13:49,940 --> 00:13:55,550 And we got our products collection view here which I think even though it says it's been set I think 201 00:13:55,610 --> 00:13:58,670 it's not probably set back in the storyboard here. 202 00:13:58,730 --> 00:14:04,130 Select your controller right click it and you see that product's collection is definitely not set it's 203 00:14:04,130 --> 00:14:07,010 lying to us as drag it over there. 204 00:14:07,310 --> 00:14:08,340 OK. 205 00:14:08,340 --> 00:14:13,790 And let's also make sure our cell has a reuse identifier so go to your product cell and it does not 206 00:14:14,390 --> 00:14:16,010 give us a reuse identifier. 207 00:14:16,100 --> 00:14:17,920 And we are going to call it product cell. 208 00:14:18,050 --> 00:14:21,380 You have to have this so the cells can be reused. 209 00:14:21,380 --> 00:14:21,790 OK. 210 00:14:21,980 --> 00:14:23,320 Let's go ahead and give this a spin. 211 00:14:23,400 --> 00:14:24,370 Let's just see where we are. 212 00:14:24,380 --> 00:14:28,440 See for even runs I'm feeling good about it so far. 213 00:14:28,460 --> 00:14:30,200 We could have forgotten something though. 214 00:14:30,710 --> 00:14:31,050 OK. 215 00:14:31,100 --> 00:14:33,000 Moment of Truth when we click one of these. 216 00:14:33,080 --> 00:14:34,290 We should see the next screen load. 217 00:14:34,310 --> 00:14:35,550 And it should show the appropriate data. 218 00:14:35,550 --> 00:14:42,680 So I'm going click hoodies and it's working so we've got our hoodies Dove soaps logo gray red gray and 219 00:14:42,680 --> 00:14:45,470 black so our data is definitely populating. 220 00:14:45,470 --> 00:14:47,810 As expected a couple things. 221 00:14:47,820 --> 00:14:51,390 Is this code Her swag is really annoying and it's not supposed to be there. 222 00:14:51,470 --> 00:14:54,410 The design that our designer gave us was just the arrow itself. 223 00:14:54,590 --> 00:14:56,210 And also there's not a title here. 224 00:14:56,390 --> 00:15:01,820 I think we need a title to show what kind of products it is and what kind of products we're showing 225 00:15:01,820 --> 00:15:02,320 rather. 226 00:15:02,510 --> 00:15:04,200 And shirts. 227 00:15:04,610 --> 00:15:06,110 So you know this looks pretty good. 228 00:15:06,580 --> 00:15:07,540 I kind of like it. 229 00:15:10,160 --> 00:15:11,980 Yeah yeah yeah yeah. 230 00:15:12,700 --> 00:15:13,130 I like it. 231 00:15:13,130 --> 00:15:14,770 So let's let's fix a couple of things. 232 00:15:14,760 --> 00:15:17,500 So what we'll do and this is empty which is great. 233 00:15:17,500 --> 00:15:23,330 So what we'll do is we'll get rid of this text here and then we'll set a title to let's the title first. 234 00:15:23,830 --> 00:15:32,610 So what we'll do is save this in the products we see when we're initialising this data here. 235 00:15:32,780 --> 00:15:35,150 Let's just go ahead and set the title and that's easy. 236 00:15:35,180 --> 00:15:44,240 As simple as saying navigation item Daut title equals we'll say category that title so to grab the title 237 00:15:44,240 --> 00:15:45,570 of the navigation bar. 238 00:15:45,680 --> 00:15:45,960 OK. 239 00:15:45,960 --> 00:15:49,520 All you have to do is grab navigation item that title and it knows how to find it and then you set it 240 00:15:49,520 --> 00:15:51,870 to the title here that is. 241 00:15:52,270 --> 00:15:53,570 That's really easy. 242 00:15:53,570 --> 00:15:58,460 The harder one is the button and you would think maybe you would do something like this navigation item 243 00:15:58,460 --> 00:16:03,590 that let's say back button right here or backbiter button item and then you know oh look at the title 244 00:16:03,590 --> 00:16:08,310 we can set the title like this equals you know let's say an empty string but it doesn't work. 245 00:16:08,360 --> 00:16:15,320 Unfortunately it does not recognize this because the the back button actually belongs to the previous 246 00:16:15,320 --> 00:16:16,210 few controller. 247 00:16:16,210 --> 00:16:16,470 OK. 248 00:16:16,460 --> 00:16:19,140 It does not belong to this one belongs to the previous one. 249 00:16:19,210 --> 00:16:21,340 So we have to do is actually go in the categories. 250 00:16:21,810 --> 00:16:22,540 OK. 251 00:16:22,600 --> 00:16:27,300 And what we can do in the categories we see is we can just set it here and prepare for segue. 252 00:16:27,310 --> 00:16:28,090 All right. 253 00:16:28,090 --> 00:16:36,370 So we can right here create a bar button item so bar button equals you bar button item you have to create 254 00:16:36,370 --> 00:16:41,140 a new one you can't modify it again like I said it's strange you think you could but you can't create 255 00:16:41,140 --> 00:16:41,860 a new one. 256 00:16:41,920 --> 00:16:44,880 And what would this was say bar button title. 257 00:16:45,010 --> 00:16:46,720 Make it an empty string. 258 00:16:47,070 --> 00:16:53,030 And now will say navigation item back bar button item equals bar button. 259 00:16:53,100 --> 00:16:55,090 Place what's there with something new. 260 00:16:55,360 --> 00:16:57,340 OK. 261 00:16:57,550 --> 00:17:00,900 And you know what I think I want to do this before I initialize anything. 262 00:17:00,970 --> 00:17:04,570 Just for good measure like so. 263 00:17:08,080 --> 00:17:09,040 Cool. 264 00:17:09,130 --> 00:17:11,250 So we've just created a bar button item. 265 00:17:11,350 --> 00:17:12,800 We said it with an empty title. 266 00:17:12,820 --> 00:17:17,520 And then what we've done is we've set the navigation item back bar button item to this new item here. 267 00:17:17,560 --> 00:17:25,450 So let's go ahead and see if that works shirts it says at the top and has the backbone Canpotex which 268 00:17:25,450 --> 00:17:26,170 is great. 269 00:17:26,170 --> 00:17:30,040 Hoodie's says hoodies hats say hats. 270 00:17:30,040 --> 00:17:30,960 Prices are different everything. 271 00:17:30,960 --> 00:17:31,720 This is really good. 272 00:17:31,720 --> 00:17:34,160 What you've done here is very important. 273 00:17:34,250 --> 00:17:34,810 OK. 274 00:17:34,960 --> 00:17:39,820 If you can if you don't have everything memorized that we've done in this series on this app then you're 275 00:17:39,820 --> 00:17:46,800 not likely to get a job as as an OS developer and the reason why is displaying data is so critical. 276 00:17:46,900 --> 00:17:50,050 OK and we've written what I call good clean code. 277 00:17:50,110 --> 00:17:52,910 So if you write code like this you'll you'll impress people. 278 00:17:53,170 --> 00:17:57,850 And what we've done is we've worked with table use reusable cells. 279 00:17:57,990 --> 00:18:02,400 We've worked with collection use which our grid system again collection of use can go horizontal if 280 00:18:02,400 --> 00:18:03,710 you want to swipe horizontally. 281 00:18:03,720 --> 00:18:10,890 You could let's say that you wanted Let's say that you wanted to be able to swipe horizontally here 282 00:18:10,920 --> 00:18:12,360 but swipe up and down here maybe this. 283 00:18:12,390 --> 00:18:17,970 Maybe we just had one page and this said hats and said shirts what you could do is you could actually 284 00:18:17,970 --> 00:18:24,330 have a table view and each cell inside the table is actually a collection view OK with a horizontal 285 00:18:24,330 --> 00:18:24,690 scroll. 286 00:18:24,690 --> 00:18:26,160 So the table view goes vertical. 287 00:18:26,160 --> 00:18:27,920 But the collection below goes horizontal. 288 00:18:28,020 --> 00:18:32,340 And so you could have this row here on the table of you cell which is a collection of you goes from 289 00:18:32,340 --> 00:18:36,720 left to right left or right left or right and that's how you would build something that goes up and 290 00:18:36,720 --> 00:18:39,140 down and left and right which is really cool of course. 291 00:18:39,270 --> 00:18:43,740 The collection itself can also do that functionality so you can do a collection view within a collection 292 00:18:43,740 --> 00:18:44,390 view. 293 00:18:44,460 --> 00:18:47,820 And we did a grid spacing here the spacing was automatic for us. 294 00:18:47,820 --> 00:18:51,030 You can change the spacing you can change the layouts and do some other nifty things. 295 00:18:51,030 --> 00:18:54,440 We didn't even begin to cover all of that here but you can change all that. 296 00:18:54,570 --> 00:19:00,480 And this has really come together you've learned how to host data in a data service using the singleton 297 00:19:00,480 --> 00:19:01,100 pattern. 298 00:19:01,110 --> 00:19:07,590 OK one instance of this class in memory you've also learned the basics of implementing the delegate 299 00:19:07,590 --> 00:19:12,720 pattern which is you have classes implement some type of protocol. 300 00:19:12,770 --> 00:19:14,220 And I will abide by these rules. 301 00:19:14,220 --> 00:19:18,930 And once those protocols are implemented X code will force you to implement the code needed for it such 302 00:19:18,930 --> 00:19:23,360 as sell for item index path etc. and then you implement those things. 303 00:19:23,370 --> 00:19:27,780 You have to make sure you set the data source and delegate on your table view or collection of view. 304 00:19:27,810 --> 00:19:31,710 Otherwise your app will not run appropriately. 305 00:19:31,740 --> 00:19:35,190 And a lot of new developers do that so you'll learn a lot of things here. 306 00:19:35,190 --> 00:19:38,920 This is the basis and foundation of what you're going to do whenever working with data. 307 00:19:39,030 --> 00:19:41,200 And we've taught you everything here the right way. 308 00:19:41,310 --> 00:19:45,320 OK the Apple way and I'm I'm happy. 309 00:19:45,360 --> 00:19:45,990 I think it's good. 310 00:19:45,990 --> 00:19:47,440 So congratulations. 311 00:19:47,490 --> 00:19:48,810 This is good stuff here. 312 00:19:48,900 --> 00:19:54,000 And let's move on and forward two other amazing apps Mark Price at deps slopes dot com. 313 00:19:54,000 --> 00:19:54,740 See you next time.