WEBVTT 00:07.180 --> 00:08.290 Welcome back. 00:08.290 --> 00:15.010 So we've reached a point where we can't really test or develop any further until we start saving things. 00:15.460 --> 00:21.700 Well, yes, I can switch my widget to the enter name widget, but what happens when I enter the name 00:21.700 --> 00:23.680 Stephen and click new slot? 00:23.680 --> 00:25.270 Well, nothing happens, right? 00:25.420 --> 00:29.050 This is when we need to start saving things. 00:29.050 --> 00:36.040 We have to save that name and designate this slot now to be taken, and then switch this widget to the 00:36.040 --> 00:37.360 taken widget. 00:37.360 --> 00:39.100 Let's take a look at what that looks like. 00:39.100 --> 00:41.440 Here's the taken widget. 00:41.440 --> 00:45.580 It's going to switch now to this widget. 00:45.580 --> 00:53.350 And while it does have level and dungeon and we don't quite know what to put there yet, it has player 00:53.350 --> 00:55.810 name and that needs to be updated. 00:56.200 --> 01:04.630 So we need to start saving things and to save something to disk we have to create a save game object. 01:04.630 --> 01:06.820 So we're going to create a save game object. 01:06.820 --> 01:09.790 We're going to go to C plus plus classes Aura Public. 01:09.790 --> 01:14.020 And I'm going to stick this in the game folder next to our game mode. 01:14.020 --> 01:14.560 Why. 01:14.590 --> 01:18.130 Because I just feel like it's related enough to the game mode. 01:18.130 --> 01:23.020 And it's going to be closely intimate with the game mode in some ways. 01:23.020 --> 01:24.460 So we're going to create it here. 01:24.460 --> 01:30.070 Now I'm going to create a class of type save game. 01:30.280 --> 01:32.110 It's a save game object. 01:32.110 --> 01:35.050 This is how we can save data to disk. 01:35.050 --> 01:36.370 We're going to click next. 01:36.370 --> 01:38.650 And this goes right into game. 01:38.890 --> 01:43.300 And I'm going to call this load screen save game. 01:43.750 --> 01:49.420 So this is what we're going to use to save data from the load screen. 01:49.780 --> 01:53.920 And I'm going to click Create Class I'm going to click no and close the editor. 01:54.490 --> 01:59.080 And open up my new load screen save game object. 01:59.860 --> 02:04.870 Here it is now load screen save game needs a couple of variables. 02:05.420 --> 02:09.350 I'm going to make a public section and just have a couple public variables. 02:09.350 --> 02:17.150 And when we load and save data, we identify that saved data by name. 02:17.150 --> 02:18.920 We can use an F string. 02:19.610 --> 02:21.800 We can call this slot name. 02:22.610 --> 02:28.280 And we can initialize this to an empty f string and make this a uproperty. 02:28.280 --> 02:32.930 Now, a name is not the only thing we identify our save data with. 02:32.930 --> 02:36.890 We also identify our save data with an int 32. 02:36.890 --> 02:39.650 So we're going to have a slot index as well. 02:40.010 --> 02:42.110 And this will be zero by default. 02:43.130 --> 02:45.410 And we'll also get a uproperty. 02:45.500 --> 02:54.650 So whenever we save data we have to specify what we're saving by name and index two different values. 02:55.420 --> 03:01.750 And on top of that, our save game object can have variables for whatever it wants to save. 03:01.750 --> 03:06.670 And I'm going to save an F string called player name. 03:07.950 --> 03:12.540 And I'm going to set this to an F string with a default value. 03:12.570 --> 03:13.830 Default name. 03:13.860 --> 03:19.230 Now you might be wondering how come we can't just use player name instead of slot name and identify 03:19.230 --> 03:23.220 the slot by the name instead of having two strings? 03:23.250 --> 03:29.010 Well, what if you want to save one slot with your name, and then save another slot with the same name? 03:29.010 --> 03:34.290 You couldn't do that if you were using the name to identify your save slot. 03:34.290 --> 03:38.280 So we're going to have player name as a separate variable. 03:38.700 --> 03:40.440 Okay, so we have slot index. 03:40.440 --> 03:41.670 We have slot name. 03:41.670 --> 03:43.590 How do we save data to it. 03:43.620 --> 03:48.420 Well first of all we have to pick a class from which to do this. 03:48.420 --> 03:54.900 And I'm going to choose the game mode because I feel like it's a pretty appropriate class to do this 03:54.900 --> 03:55.560 kind of thing. 03:55.560 --> 03:59.130 Game modes typically have authority over the rules of the game. 03:59.130 --> 04:01.830 I think that's closely related to saving the game. 04:01.830 --> 04:08.280 So we're going to use the game mode for this, and the game mode needs a function that can save data. 04:08.400 --> 04:11.100 So I'm going to make a function that can save slot data. 04:11.100 --> 04:12.810 It's going to be a public function. 04:12.810 --> 04:14.670 So this function will be void. 04:14.670 --> 04:17.400 And I'm going to call it save slot data. 04:17.940 --> 04:23.550 Now save slot data is going to need to know what data to save. 04:23.880 --> 04:28.080 So what are we going to pass in to save slot data. 04:28.610 --> 04:32.540 Well, I'd like to pass in our mVVM load slot. 04:32.540 --> 04:34.250 That seems kind of strange, doesn't it? 04:34.250 --> 04:37.940 But really, our mVVM is going to have data. 04:37.940 --> 04:39.710 It's going to have values stored in it. 04:39.710 --> 04:45.800 Remember, mVVM stores state and it's closely related to the view. 04:45.830 --> 04:49.010 It's going to have its own player name. 04:49.010 --> 04:52.580 In fact, we can give it an F string called player Name. 04:53.000 --> 04:53.870 And we will. 04:53.870 --> 04:58.610 And it's going to be closely related to the player name in the widget. 04:58.610 --> 05:06.410 We'll get to that when we learn how to bind variables on an mVVM ViewModel to the widget, but until 05:06.410 --> 05:15.770 then, we're just going to take our save slot data, and we're going to pass in an mVVM load slot object 05:15.770 --> 05:18.530 whenever we want to save data. 05:19.040 --> 05:23.390 And then the game mode will harvest that data and save it to disk. 05:23.930 --> 05:29.240 In fact, let's go ahead and just add a F string called Player name to load slot. 05:30.790 --> 05:32.050 We'll say F string. 05:32.050 --> 05:33.100 Player name. 05:34.370 --> 05:36.290 And we'll give it a uproperty. 05:37.160 --> 05:45.890 And here in our game mode and save slot data, we're going to take in a um VM load slot. 05:45.890 --> 05:49.850 We're going to forward declare it here passing it in by pointer. 05:49.850 --> 05:51.800 And this will be the load slot. 05:53.090 --> 05:59.480 And we also want to pass in the slot index so we can generate this definition. 06:02.490 --> 06:03.630 So how do we do that? 06:03.630 --> 06:04.440 Well, we use you. 06:04.440 --> 06:05.910 Gameplay statics. 06:09.410 --> 06:16.340 So, including Kismet, gameplay, statics and we call Create Save GameObject. 06:16.700 --> 06:20.210 Now this requires a save game class. 06:20.210 --> 06:22.190 We need a subclass of. 06:22.460 --> 06:27.560 So our game mode is going to need to know what class to create for this. 06:27.980 --> 06:32.840 So in our Game Modes header file we're going to create a subclass of. 06:33.320 --> 06:35.090 It's going to be a u save game. 06:35.090 --> 06:37.040 It has to be U save game. 06:37.040 --> 06:44.870 We'll add a forward declaration and this will be load screen save game class. 06:45.730 --> 06:49.420 And we'll set this from the blueprint, so we'll give it a U property. 06:51.040 --> 06:59.920 And edit defaults only, and in the cpp file we'll call create save game object with load screen save 06:59.920 --> 07:00.970 game class. 07:00.970 --> 07:04.000 And we'll store this in a local you save game. 07:05.470 --> 07:09.910 So this function has to take a subclass of you save game. 07:10.760 --> 07:13.850 It can't be of a child class of that. 07:14.000 --> 07:16.220 We'll call this save game object. 07:17.720 --> 07:18.800 But here's the thing. 07:18.800 --> 07:22.400 We should check to see if this particular slot exists already. 07:22.400 --> 07:31.460 If a slot exists with the name and slot index associated with this load slot, which means our mVVM 07:31.460 --> 07:36.800 should also have a load slot name and a slot index as well. 07:36.800 --> 07:45.590 So in mVVM load slot, not only should we have a player name, we should also have a load slot name 07:47.360 --> 07:50.840 and we should also have a slot index. 07:51.440 --> 07:58.940 That way, our mVVM is going to be associated with the slot name and the slot index, and our game mode 07:58.940 --> 08:01.040 can check to see if it exists already. 08:01.040 --> 08:02.390 So how do we do that? 08:02.690 --> 08:14.540 Well, we say if you gameplay statics does save game exist and we take our load slot, the mVVM passed 08:14.540 --> 08:15.110 in. 08:15.720 --> 08:22.680 And get the load slot name and pass that in and get its slot index, which we have the slot index here. 08:24.780 --> 08:26.190 If it already exists. 08:26.190 --> 08:31.860 We want to delete it because we're trying to save to this slot and we want it to be gone. 08:31.860 --> 08:39.810 So we're going to take you gameplay statics delete game and slot using load slot. 08:41.100 --> 08:44.610 Load slot name and the slot index. 08:45.240 --> 08:51.270 So we'll delete it if it already exists, since we're trying to save to that slot, and then we'll create 08:51.270 --> 08:51.600 one. 08:51.600 --> 08:56.040 Now after we've created one, we cast to load screen save game. 08:56.040 --> 09:04.110 So we're going to say you load screen save game load screen save game equals. 09:04.440 --> 09:08.520 And we're going to cast to you load screen save game. 09:10.120 --> 09:11.740 Save game object. 09:14.740 --> 09:17.110 And then we can take load screen save game. 09:20.350 --> 09:25.120 And take its player name and set it to the player name and load slot. 09:28.990 --> 09:29.410 Right. 09:29.410 --> 09:36.700 So we're calling save slot data passing in load slot checking to see if this slot already exists with 09:36.700 --> 09:38.140 this name and index. 09:38.140 --> 09:46.000 If not, we create a save game object and then we cast it to load screen save game and set its player 09:46.000 --> 09:46.600 name. 09:46.600 --> 09:52.480 Now at this point we have a save game object of this type with its player name set. 09:52.480 --> 09:56.140 So now is the time to actually save the game. 09:56.140 --> 10:00.370 So we use you gameplay statics for that and we use save game to slot. 10:02.880 --> 10:08.760 And this takes that load screen save game object load screen save game. 10:08.760 --> 10:12.810 And then we need to specify the slot name and the slot index. 10:12.810 --> 10:15.150 And that is in our load slot. 10:15.150 --> 10:18.810 We just gave it slot name load slot name. 10:18.810 --> 10:21.600 And we have our slot index. 10:22.050 --> 10:25.620 So save slot data is going to save that data. 10:25.620 --> 10:33.120 So now that the game mode has the capability of saving slot data using save slot data, we can go now 10:33.120 --> 10:36.810 into our load screen view model. 10:36.810 --> 10:37.680 Here it is. 10:38.600 --> 10:43.370 Because we have a blueprint callable function for when new slot button has been pressed. 10:44.030 --> 10:45.080 This has the slot. 10:45.080 --> 10:46.400 It has the entered name. 10:46.400 --> 10:47.960 We can save that. 10:47.960 --> 10:52.370 So we just need to get the game mode with a Ora game mode base. 10:53.060 --> 10:55.040 We'll call it Ora game mode. 10:55.940 --> 10:57.800 We need to get game mode from you. 10:57.800 --> 10:58.250 Gameplay. 10:58.250 --> 10:59.360 Statics. 11:01.480 --> 11:03.610 So we'll get that include there. 11:03.610 --> 11:05.440 We can call get game mode. 11:05.470 --> 11:12.370 Now this requires a world context object, but this returns a a game mode base. 11:12.370 --> 11:15.130 We need to cast a or a game mode base. 11:15.130 --> 11:16.540 So let's cast it. 11:24.670 --> 11:28.210 And once we have it, we can now save data. 11:28.210 --> 11:30.370 But we need to know which slot. 11:30.370 --> 11:32.710 Well, we have our load slots map. 11:32.710 --> 11:35.740 We can index it with slot. 11:36.340 --> 11:37.480 It's called load slots. 11:37.480 --> 11:39.160 We can index it with slot. 11:39.490 --> 11:43.060 And we have a player name that we can set. 11:44.060 --> 11:49.670 And we can set that to the entered name that was passed in to the blueprint callable function. 11:49.670 --> 11:53.960 Once we've set its name, we can save that slot data. 11:53.960 --> 11:55.910 We can take our A game mode. 11:57.070 --> 12:02.710 And call save slot data using this view model and load slots. 12:02.740 --> 12:07.150 Load slots of slot and pass in that slot. 12:07.960 --> 12:09.280 But here's the thing. 12:09.280 --> 12:15.520 We're identifying these slots by a slot name now, which means we need to be setting those. 12:15.970 --> 12:20.680 And we should set them as soon as we create them and initialize load slots. 12:20.680 --> 12:27.340 So as soon as I create load slot zero I'm going to take that slot load slot zero. 12:27.340 --> 12:31.390 And I'm going to set its slot load slot name. 12:32.020 --> 12:35.170 I'm going to set it to an F string. 12:36.220 --> 12:39.220 And we'll just give these each unique names. 12:39.220 --> 12:41.170 I'll just call it load slot zero. 12:41.200 --> 12:43.630 This is just a way to identify it. 12:43.990 --> 12:45.820 And I'm going to do it for one and two. 12:45.850 --> 12:47.050 So load slot one. 12:47.050 --> 12:50.440 We'll set load slot name on it to load slot one. 12:50.860 --> 12:56.080 And for two we'll take that one and set its load slot name. 12:56.350 --> 12:58.720 So now these each have unique names. 12:58.720 --> 13:03.310 And when we save our slot data we'll save with a unique name. 13:04.010 --> 13:05.930 Okay, so now we're saving data. 13:05.930 --> 13:12.140 Now we don't really have an easy way to test this until we start loading data. 13:12.680 --> 13:16.970 So we still have a few steps to go, but now at least we're saving data. 13:16.970 --> 13:21.140 At least we can check to see if we get a successful compile. 13:22.410 --> 13:22.830 All right. 13:22.830 --> 13:23.310 We do. 13:23.310 --> 13:29.850 And actually, there's one thing we can check when we click on new slot button pressed, we can tell 13:29.850 --> 13:33.930 that load slot to broadcast a new widget switcher index. 13:33.930 --> 13:37.230 We can broadcast a value of say two. 13:37.260 --> 13:40.950 We'll just make it hard coded to until we code this completely. 13:40.950 --> 13:46.260 But we'll just call initialize slot here and we can at least test that part. 13:46.260 --> 13:52.920 So right here under new slot button pressed we'll take that load slots of slot. 13:56.780 --> 14:01.640 We'll call its initialized slot function, and at least we'll see that change. 14:01.760 --> 14:04.250 So let's compile and go back into the editor. 14:06.120 --> 14:07.590 And back in the editor. 14:07.590 --> 14:11.670 We're going to go ahead and make a save game Object Blueprint. 14:11.670 --> 14:13.920 We'll go into the game folder and do it. 14:13.950 --> 14:18.780 New blueprint class load screen save game. 14:19.440 --> 14:27.390 We'll make a blueprint version of this BP load screen save game, and we'll go into load screen game 14:27.390 --> 14:28.980 mode and set this. 14:28.980 --> 14:33.060 We'll go ahead and find load screen save game class. 14:33.060 --> 14:34.410 We'll set that there. 14:37.860 --> 14:39.030 Save all. 14:39.870 --> 14:42.270 And go to our load menu and press play. 14:42.270 --> 14:49.530 And at least we know that if we click on Enter Name and enter some text and click New Slot, then we 14:49.530 --> 14:51.960 switch to this widget. 14:51.990 --> 14:55.410 Now we're not showing the player name that we entered in. 14:55.410 --> 14:56.910 We still need to do that. 14:56.910 --> 15:03.570 And that's going to require actually binding variables on the widget to variables in their view model. 15:03.570 --> 15:06.960 And we'll get to see how that is closely related. 15:06.960 --> 15:08.640 We'll do that next. 15:08.670 --> 15:09.720 I'll see you soon.