1 00:00:08,020 --> 00:00:13,840 Hey buddy this is Caleb with slopes and in this video we're going to build our data service it's a singleton 2 00:00:13,840 --> 00:00:18,370 class that we're going to use to interface with our firebase databased. 3 00:00:18,370 --> 00:00:19,710 Very very cool. 4 00:00:19,720 --> 00:00:25,360 So let's go ahead and pull open our code project and what we're going to do to begin is to create a 5 00:00:25,360 --> 00:00:27,760 new Swift file in our services group. 6 00:00:27,760 --> 00:00:33,580 So right click on services click new file and create a new Swift file. 7 00:00:33,580 --> 00:00:38,680 Now of course we're going to name this data service and make sure that you are adding it to the proper 8 00:00:38,680 --> 00:00:45,380 target and click Create now inside the data service we need to create a class just like you might expect 9 00:00:45,500 --> 00:00:49,500 by typing class data service. 10 00:00:49,520 --> 00:00:56,420 Then to make it a singleton class meaning to make it accessible to any other class throughout the life's 11 00:00:56,780 --> 00:01:02,780 lifecycle of this application go ahead and create a static variable static Erse that it constant actually 12 00:01:02,780 --> 00:01:05,620 static let and then call it instance. 13 00:01:05,660 --> 00:01:11,090 And we're going to just instantiate data service so basically we're creating an instance of this view 14 00:01:11,090 --> 00:01:14,170 control of this class inside itself. 15 00:01:14,240 --> 00:01:14,780 Very cool. 16 00:01:14,780 --> 00:01:15,890 Not too bad. 17 00:01:15,890 --> 00:01:20,260 Now what we need to do is we need to set up a few different things. 18 00:01:20,330 --> 00:01:22,940 But before we do that we need to import firebase. 19 00:01:22,940 --> 00:01:25,120 So go ahead and do that. 20 00:01:25,340 --> 00:01:31,760 And now we can actually communicate with firebase now that we've imported it which is very cool. 21 00:01:32,020 --> 00:01:32,420 OK. 22 00:01:32,600 --> 00:01:37,490 So now what we're going to do is we're going to go ahead and create a constant outside of our class 23 00:01:37,490 --> 00:01:38,930 called D-B base. 24 00:01:38,930 --> 00:01:46,280 Go ahead and type let DBI bass in all caps and we're going to set this to basically allow us to access 25 00:01:46,280 --> 00:01:49,520 our database like the base you Arel of our database. 26 00:01:49,760 --> 00:01:53,310 To do that go ahead and type database database. 27 00:01:53,420 --> 00:01:57,610 That means the primary database and then dot reference. 28 00:01:57,800 --> 00:01:58,370 OK. 29 00:01:58,670 --> 00:02:05,880 And if you look this is a function that gets a F-I our database reference for the root of your firebase 30 00:02:05,900 --> 00:02:07,010 database. 31 00:02:07,010 --> 00:02:14,180 Now if I take you over here to firebase I went into our project I went into the database and you'll 32 00:02:14,180 --> 00:02:16,970 notice right here there's a u r l. 33 00:02:16,970 --> 00:02:21,800 This is the base you are l of our database and I'll show you how the rest of it works in a second but 34 00:02:21,800 --> 00:02:27,620 that's what you need to know this you r l is what we're going to use for our base you are all of our 35 00:02:27,620 --> 00:02:28,580 server. 36 00:02:28,580 --> 00:02:34,640 So this is instantiated outside of our class so that it's accessible to us in the class because this 37 00:02:34,640 --> 00:02:39,610 class by itself doesn't have any initialiser So we're initializing it outside of the class on purpose. 38 00:02:39,620 --> 00:02:43,290 So now we're going to go ahead and make for private variables. 39 00:02:43,290 --> 00:02:51,920 One variable that's going to hold the value of D-B base one that's going to hold a reference to a user's 40 00:02:52,010 --> 00:02:55,590 group or in firebase we call them a child. 41 00:02:55,590 --> 00:03:00,740 So inside of our base you are l if we add a child it means we're adding a group we're like a subgroup 42 00:03:00,740 --> 00:03:03,830 thing like nested folders kind of I'll show you later. 43 00:03:03,830 --> 00:03:10,370 But for now we need to know we're going to create a variable for our base you Aurel the your for the 44 00:03:10,370 --> 00:03:15,650 users that we're going to store because if you look at our simulator here we need to basically be able 45 00:03:15,650 --> 00:03:22,310 to hold information for all the users all the emails and all of the account types for the groups we 46 00:03:22,310 --> 00:03:27,770 need to hold all of the group information as well as all the messages in each group. 47 00:03:27,800 --> 00:03:30,750 We also need to be able to hold all of the information from the feed. 48 00:03:30,760 --> 00:03:35,690 So we're going to make for different variables and we're going to use those to store those references 49 00:03:35,690 --> 00:03:37,040 to the firebase database. 50 00:03:37,040 --> 00:03:40,590 So let's go ahead and do that and we're going to use data hiding as well. 51 00:03:40,700 --> 00:03:46,370 So that basically we can only set these values from inside the data service so that nobody else can 52 00:03:46,370 --> 00:03:52,400 access them no other class or no other method can access these except for the data service itself. 53 00:03:52,490 --> 00:03:53,920 Good way to be a safe coder. 54 00:03:54,020 --> 00:03:58,140 So go ahead and type private var setting it to be a private variable. 55 00:03:58,460 --> 00:04:04,520 And we're going to use underscore ref base that's going to be equal to D-B base. 56 00:04:04,520 --> 00:04:10,810 OK so that's our database and we're going to create an accessor to set the value of this in just a second. 57 00:04:10,820 --> 00:04:13,960 But for now we're going to just leave it as D-B base. 58 00:04:13,970 --> 00:04:24,950 Now we're going to do another one here private var ref users and this is going to be used to save our 59 00:04:24,950 --> 00:04:28,400 users into their own sort of folder in firebase. 60 00:04:28,520 --> 00:04:36,260 Now to do that we're going to basically just append a child to D-B base like this D.B base child and 61 00:04:36,260 --> 00:04:39,660 the path string is going to be users. 62 00:04:39,800 --> 00:04:40,490 OK. 63 00:04:40,670 --> 00:04:48,200 Now the cool thing about firebase is if a value does not exist when you go to try to save something 64 00:04:48,230 --> 00:04:53,570 to a certain child if it doesn't already exist it will create it thus preventing crashes. 65 00:04:53,560 --> 00:04:54,530 It's pretty amazing. 66 00:04:54,710 --> 00:04:59,420 So I'll show you how that works as well later but for now just think if this is like we're creating 67 00:04:59,420 --> 00:05:14,000 a folder to hold all the users can let's do it again a private var ref groups equals D-B base dot child 68 00:05:14,330 --> 00:05:15,820 and the path string is. 69 00:05:15,820 --> 00:05:25,820 Groups just like users and then go ahead and type private var ref feed trips to all caps equals DB base 70 00:05:26,180 --> 00:05:29,760 child and the path string is feed. 71 00:05:29,810 --> 00:05:30,450 OK. 72 00:05:30,800 --> 00:05:31,580 Very very cool. 73 00:05:31,580 --> 00:05:33,050 So these are private variables. 74 00:05:33,050 --> 00:05:38,210 Now we're going to create public variables in order to set the value and actually be able to use the 75 00:05:38,210 --> 00:05:38,810 information. 76 00:05:38,840 --> 00:05:48,240 So go ahead and we're going to create one 4-F base type var ref base whip's of type database reference 77 00:05:49,230 --> 00:05:53,250 and then inside of this we're basically just going to return ref base. 78 00:05:53,280 --> 00:05:54,090 OK. 79 00:05:54,960 --> 00:06:03,900 Next we're going to go ahead and create one for ref users of type database reference. 80 00:06:03,900 --> 00:06:06,080 And we're going to return ref. 81 00:06:06,110 --> 00:06:12,350 Users can't keep doing this for the others for groups and feed ref groups. 82 00:06:12,360 --> 00:06:18,960 Whoopsies of type database reference return ref groups. 83 00:06:19,110 --> 00:06:26,940 And finally var refeed of type database reference return Ref field. 84 00:06:26,940 --> 00:06:31,340 All right so now we have four public variables that are accessing the private ones. 85 00:06:31,350 --> 00:06:38,700 So now what's going to happen is if we ever need to set a value or access a value we can access ref 86 00:06:38,730 --> 00:06:39,260 groups. 87 00:06:39,270 --> 00:06:44,160 And what it's going to do is it's going to give us the value of these private variables so we can access 88 00:06:44,160 --> 00:06:51,000 the information of these by pulling from a private variable that way these themselves if they're modified 89 00:06:51,000 --> 00:06:55,110 it's going to only return the value that we've set which is pretty cool. 90 00:06:55,110 --> 00:06:59,850 So next what we're going to do is we're going to create a little function that's going to allow us to 91 00:06:59,880 --> 00:07:08,490 push a user into the user's feed and basically it's going to add a user into the Users folder and to 92 00:07:08,490 --> 00:07:11,520 explain this more I want to show you on firebase how this works. 93 00:07:11,520 --> 00:07:14,210 So here is our database. 94 00:07:14,310 --> 00:07:19,260 And of course you can see there's no value there's nothing in here but let's say that I wanted to add 95 00:07:19,320 --> 00:07:20,950 a user's folder. 96 00:07:21,310 --> 00:07:28,710 OK I can create a user and what I can do inside of this users directory is I can create a new user so 97 00:07:28,710 --> 00:07:34,760 maybe I create a user with an ID of that Kate has a unique ID. 98 00:07:35,130 --> 00:07:41,040 And inside this user is going to have an email and you know what let's make it a string and email and 99 00:07:41,040 --> 00:07:42,640 their e-mail is Bob. 100 00:07:42,660 --> 00:07:43,650 Bob dotcom. 101 00:07:44,070 --> 00:07:44,950 OK. 102 00:07:45,450 --> 00:07:51,960 And what else is our user going to have our users going to have an account type and their account type 103 00:07:51,960 --> 00:07:53,210 is e-mail. 104 00:07:53,370 --> 00:07:55,900 And when I click and watch what happens. 105 00:07:55,900 --> 00:07:58,740 Now there is a user's folder. 106 00:07:58,740 --> 00:08:04,770 If I open it up there is my user's I.D. and if I open that up you can see that e-mail and the account 107 00:08:04,770 --> 00:08:05,750 type values. 108 00:08:05,940 --> 00:08:10,500 So that's sort of how firebase works we're going to create a function that pushes that information to 109 00:08:10,500 --> 00:08:11,360 firebase. 110 00:08:11,370 --> 00:08:13,140 So let's go ahead and delete that. 111 00:08:13,350 --> 00:08:17,970 And just like that it's gone head back into X code. 112 00:08:17,970 --> 00:08:18,720 And here we go. 113 00:08:18,720 --> 00:08:19,870 Let's create that function. 114 00:08:19,920 --> 00:08:23,040 And you know what I'm going to actually give us some space here so we can see. 115 00:08:23,550 --> 00:08:32,250 And beneath this we're going to go ahead and call phunk create D-B user and we need to think in order 116 00:08:32,250 --> 00:08:33,200 to create a user. 117 00:08:33,200 --> 00:08:39,120 I just showed you I used a unique key and in this app we're going to actually call it the you I.D. the 118 00:08:39,120 --> 00:08:41,010 unique identifier. 119 00:08:41,010 --> 00:08:46,320 So let's go ahead and in order to create a database user We're going to pass it a unique ID of type 120 00:08:46,320 --> 00:08:51,530 string and we're also going to go ahead and pass it user data. 121 00:08:51,660 --> 00:08:59,040 Of course it needs the account type it needs of course it needs the account type it needs to email all 122 00:08:59,040 --> 00:08:59,890 that stuff. 123 00:08:59,940 --> 00:09:05,880 And the way we're going to pass that in is by giving it a dictionary wups a dictionary of type string 124 00:09:06,390 --> 00:09:12,470 and any K so that means we can pass it a string and any value can be on the other side. 125 00:09:12,810 --> 00:09:17,610 Now in order to actually push values up to firebase what we're going to do is we're first going to call 126 00:09:17,610 --> 00:09:25,860 ref users because we want to access the user reference which is at our default database slash users. 127 00:09:26,010 --> 00:09:29,780 And once we are in there we're going to create a new child. 128 00:09:30,210 --> 00:09:31,200 OK. 129 00:09:31,200 --> 00:09:35,140 Now the path string we want to give the ID right. 130 00:09:35,190 --> 00:09:41,490 We want the folder inside of users to be named the unique identifier for the user so let's pass in wups 131 00:09:42,120 --> 00:09:45,020 let's pass in the ID as the path string. 132 00:09:45,180 --> 00:09:48,990 And then inside of that we want to show the dictionary of user data. 133 00:09:48,990 --> 00:09:52,560 So go ahead and call update child values. 134 00:09:52,800 --> 00:09:58,680 That means that inside this unique child we're going to pass in the user data dictionary and you probably 135 00:09:58,680 --> 00:10:00,960 noticed that it's asking for a dictionary. 136 00:10:01,110 --> 00:10:05,210 Let's go ahead and pass that in user data. 137 00:10:05,280 --> 00:10:11,730 So believe it or not this function can be used to create a firebase user and then the next video what 138 00:10:11,730 --> 00:10:16,260 we're going to do is we're going to set up our authentication view controller our log in view controller 139 00:10:16,260 --> 00:10:20,680 and we're going to start pushing users up to firebase and authenticating them with their email. 140 00:10:20,700 --> 00:10:21,840 Super super cool. 141 00:10:21,960 --> 00:10:22,650 Awesome job. 142 00:10:22,650 --> 00:10:24,300 And we'll see in the next video.