WEBVTT 00:06.810 --> 00:07.950 Welcome back. 00:07.980 --> 00:12.810 In this video, we're going to take care of an edge case, but it's actually an important edge case. 00:12.810 --> 00:19.590 And that's when we have our spell menu open with one of our icons selected and we happen to level up. 00:19.860 --> 00:26.330 So if we level up with an icon selected, we expect those buttons to update, but they don't. 00:26.340 --> 00:29.640 And there are two things that should trigger the update. 00:29.670 --> 00:37.970 One is when spell points change, we just changed from 0 to 1 spell points with an equipped ability 00:37.980 --> 00:42.840 globe selected and we expect the spend point button to be enabled. 00:42.960 --> 00:44.130 That's one case. 00:44.130 --> 00:52.230 And another is if we have a locked spell globe selected and we level up and we expect. 00:53.050 --> 00:57.430 Once it becomes eligible for the spend point button to be enabled. 00:57.430 --> 01:05.260 And for that reason, we're going to need to broadcast those two booleans for the enabled status of 01:05.260 --> 01:10.570 these buttons when spell points changes and when an ability status changes. 01:12.070 --> 01:13.780 So we need to handle that. 01:14.200 --> 01:18.910 So I'm going to close out of the editor and back in our spell menu widget controller. 01:18.910 --> 01:24.490 I'm looking at buying callbacks to dependencies because we have two lambdas here. 01:24.520 --> 01:31.270 One is bound to ability status changed and one is bound to on spell points change delegate. 01:31.660 --> 01:38.590 Now, every time the status of an ability changes, we need to know what the currently selected ability 01:38.590 --> 01:42.940 is, which we're not really setting when we click on a spell globe. 01:43.180 --> 01:45.730 Same goes for when a spell point changes. 01:45.730 --> 01:48.670 We need to know what the currently selected ability is. 01:48.910 --> 01:50.440 So we need to store that. 01:50.440 --> 01:56.830 We could store it as a gameplay tag, for example, but we also need to store that as current status 01:56.830 --> 01:57.710 as well. 01:57.790 --> 01:59.500 And here's the reason why. 01:59.530 --> 02:07.930 When we level up, both, the status of some abilities might change and our spell points is going to 02:07.930 --> 02:08.680 change. 02:08.980 --> 02:15.710 Now let's just say that we've selected a spell globe that is currently locked and that we've just leveled 02:15.710 --> 02:21.830 up and that we now meet the level requirement for that spell, which means it should now be eligible. 02:22.350 --> 02:26.430 In that case, both of these delegates will be broadcast. 02:26.980 --> 02:29.860 And it won't be clear which one will happen first. 02:30.070 --> 02:36.730 Our on spell points change delegate is broadcast from the player state and when that happens, depends 02:36.730 --> 02:42.820 on if we're on the server or if the spell points is replicated down to clients and so on. 02:43.030 --> 02:47.710 And our ability status is broadcast from the ability system component. 02:47.710 --> 02:52.510 And again, that depends on whether we're on the server, on clients and so on. 02:52.510 --> 02:55.450 So it isn't clear which will happen first. 02:55.660 --> 03:03.430 Now we could code this in a way that takes care of either situation, either one being broadcast first. 03:03.430 --> 03:10.630 But we have to be careful because if we don't keep those situations in mind, then we may not code something 03:10.630 --> 03:12.700 that works in all scenarios. 03:13.260 --> 03:19.740 Now let's imagine for a moment that the ability status changed delegate is broadcast first, which means 03:19.740 --> 03:23.610 that spell points change delegate has not yet broadcast. 03:23.790 --> 03:30.260 Now, at this point, we could check what those booleans should be. 03:30.270 --> 03:37.830 And if we check what those booleans should be, say using should enable buttons, we need to know the 03:37.830 --> 03:44.640 status and we need to know the number of spell points before we can determine those two booleans. 03:44.640 --> 03:48.630 And those are for enabling the spell points button and the equip button. 03:49.190 --> 03:54.410 Now let's say that our spell points haven't yet updated, so we've just leveled up. 03:54.900 --> 03:58.200 But let's say our spell points is still zero. 03:58.290 --> 04:04.350 Well, in that case, we would determine the wrong boolean for whether or not our spell points button 04:04.350 --> 04:05.450 should be enabled. 04:05.460 --> 04:06.720 It should be enabled. 04:06.720 --> 04:13.560 But since our spell points hasn't updated yet, it'll still be zero and that button will not enable. 04:14.290 --> 04:19.360 Now, you might think, well, that's okay, because by the time spell points does update, we'll broadcast 04:19.360 --> 04:20.340 it here too. 04:20.350 --> 04:27.760 But in that case, what if we try to get the status from, say, the ability corresponding to whatever 04:27.760 --> 04:34.840 we've selected and that that status has not yet replicated down from the ability system component to 04:34.840 --> 04:35.890 a client? 04:36.190 --> 04:41.680 Well, it's possible that our spell points will be correct, but then our status will not. 04:42.480 --> 04:48.750 Now, the way to get around this is to keep in mind that when we level up, both of these delegates 04:48.750 --> 04:50.640 will be broadcast eventually. 04:50.820 --> 04:57.330 So what we can do is when the status for a given ability changes, if it's our currently selected ability, 04:57.360 --> 04:59.870 we'll store that ability status. 04:59.880 --> 05:06.450 And then shortly after when the spell points change delegate is broadcast, we'll check what that status 05:06.480 --> 05:08.430 is that recently changed? 05:09.070 --> 05:16.900 So we'll keep a local record of the status of our currently selected ability and update it every time 05:16.930 --> 05:20.040 our spell menu widget controller catches wind of the change. 05:20.050 --> 05:24.430 And we'll also keep a local count for the spell points as well. 05:24.580 --> 05:30.880 So when we click on a spell globe, we need to keep track of what that ability is and the status for 05:30.910 --> 05:33.760 that ability which will update as soon as we know. 05:33.910 --> 05:42.880 Now, in order to keep track of both of those, I'd like a custom struct that simply has two gameplay 05:42.880 --> 05:46.750 tags, one for the ability tag and one for the status. 05:46.750 --> 05:54.310 So I'm going to make this struct and call it F selected ability and I'm not even going to expose it 05:54.310 --> 05:54.910 to blueprint. 05:54.910 --> 06:00.130 It's just an internal data structure that I'll use as a tool to keep track of our currently selected 06:00.130 --> 06:00.970 ability. 06:00.970 --> 06:04.990 And we'll have an gameplay tag called ability inside of it. 06:05.020 --> 06:11.990 We'll set it equal to an empty gameplay tag by default and we'll have an F gameplay tag called status 06:12.110 --> 06:15.740 and we'll set it equal to an empty gameplay tag as well. 06:16.640 --> 06:22.130 So we'll just have an F selected ability and we'll keep track of our currently selected ability and 06:22.130 --> 06:23.180 its status. 06:23.330 --> 06:26.260 So we'll make one right here in the private section. 06:26.270 --> 06:32.480 So it's going to be an F selected ability, we'll call it selected ability and we can initialize it 06:32.480 --> 06:34.100 with two gameplay tags. 06:34.100 --> 06:37.100 We'll use F or a gameplay tags get. 06:38.770 --> 06:42.640 And for the ability, we'll just initialize it with abilities. 06:42.670 --> 06:43.330 None. 06:43.930 --> 06:48.670 And for the status, we'll just initialize it with the locked status. 06:48.670 --> 06:57.520 So we're going to get that static get function and we'll say abilities status locked just to give it 06:57.520 --> 06:59.380 a default value. 06:59.500 --> 07:05.500 But as soon as the spell menu widget controller knows that it's changed, we'll store that new value 07:05.530 --> 07:13.210 and we'll also have an INT 32 called current spell points and we'll set that to zero by default. 07:13.810 --> 07:14.170 Okay. 07:14.170 --> 07:20.590 So what we'll do is we'll set our selected ability every time we select a spell globe. 07:20.890 --> 07:24.940 So we'll go into spell globe selected right here. 07:25.060 --> 07:32.440 And as soon as our spell globe has been selected, we know its ability tag and we've also taken a look 07:32.440 --> 07:34.120 at what its ability status is. 07:34.120 --> 07:37.360 So by this point, we know the status of it. 07:37.890 --> 07:45.600 So we can set our selected ability, we can say selected ability, dot ability equals ability tag. 07:46.890 --> 07:48.210 And we know its status too. 07:48.240 --> 07:49.860 So we can say selected ability. 07:49.890 --> 07:54.630 Dot status equals ability status. 07:56.410 --> 08:02.020 So at this point, we know our selected ability and its status and we're storing both of these. 08:02.200 --> 08:08.230 Now we need to go up to bind callbacks to dependencies, because in these lambdas we're going to know 08:08.230 --> 08:10.050 when the status has changed. 08:10.060 --> 08:11.920 So we need to update that. 08:11.920 --> 08:17.680 If the ability tag, whose status changed is equal to our currently selected ability. 08:17.830 --> 08:19.520 Otherwise, we don't care. 08:19.540 --> 08:28.780 So we're going to check we're going to say if our selected ability, dot, ability, dot matches, tag 08:28.780 --> 08:35.590 exact, and we're going to see if it matches the ability tag for the ability, that's status just changed. 08:35.860 --> 08:43.150 If that's the case, then we can take our selected ability and set its status to the newly updated status 08:43.150 --> 08:43.810 tag. 08:45.520 --> 08:52.090 And at this point, because we now know the status, we can broadcast those booleans up to our widgets 08:52.090 --> 08:54.100 so they can update the buttons. 08:54.340 --> 09:01.730 In other words, we want to create a local BOOL for each of those booleans, set those based on our 09:01.730 --> 09:08.120 currently selected ability status and our spell points that we've been setting every time they change 09:08.120 --> 09:10.160 and broadcast this delegate. 09:10.160 --> 09:14.810 So we're going to take these four lines and we're going to paste them up here. 09:18.680 --> 09:23.780 Now, the difference here is that the status is going to be status tag. 09:25.180 --> 09:29.320 And the spell points will be the spell points that we've been keeping track of. 09:29.350 --> 09:31.540 Our current spell points here. 09:32.590 --> 09:36.040 So every time they change, we'll keep track of them here. 09:36.160 --> 09:42.820 And to keep track of them, we do so right here in spell points change Delegate What we do is we set 09:42.820 --> 09:47.680 our current spell points and we set them equal to the spell points value. 09:48.040 --> 09:54.390 And as soon as spell points have changed, we also need to do these for lines right here. 09:54.400 --> 09:56.500 So we're going to paste these down here. 09:59.580 --> 10:05.380 Only the status is going to be the status that we've stored in our selected ability. 10:05.400 --> 10:07.320 So we're going to say selected ability. 10:10.710 --> 10:16.470 Dot status and we're passing in our current spell points, which is equal to spell points. 10:17.540 --> 10:19.760 And then we broadcast here. 10:20.510 --> 10:29.360 So every time the status changes or the spell points change, we update our local variables, keeping 10:29.390 --> 10:30.600 track of these. 10:30.620 --> 10:37.760 And when we level up, one will happen, then the other and both will have access to the current information 10:37.760 --> 10:40.220 that we have in the spell menu widget controller. 10:40.220 --> 10:46.760 So with that we can compile and see how this works by testing these edge cases. 10:48.900 --> 10:55.770 So back in the editor, all we need to do is press play, open our menu and select one of our spell 10:55.770 --> 10:57.630 globes and level up. 10:57.720 --> 10:59.760 So let's see what happens. 11:02.560 --> 11:03.610 One more should do it. 11:03.610 --> 11:09.310 And I'm expecting the pinpoint button to become enabled because our spell points will become one. 11:11.200 --> 11:13.210 And it does, Sure enough. 11:13.210 --> 11:19.930 Now the next edge case is going to be when we have this spell globe selected, because when we level 11:19.930 --> 11:27.010 up, it's going to become an eligible spell, which means the spin point button should also become enabled 11:27.010 --> 11:28.240 in that case. 11:28.240 --> 11:29.650 So let's level up. 11:32.580 --> 11:33.840 And there we have it. 11:33.870 --> 11:36.240 It's updating as well. 11:36.630 --> 11:38.610 So that handles the edge cases. 11:38.610 --> 11:44.040 And we can't test them all because we don't have the ability to change the statuses yet. 11:44.070 --> 11:51.690 We can't spend a point and change this spell globe from eligible to unlocked, for example. 11:51.720 --> 11:56.970 So our next steps is to start actually making these buttons functional. 11:57.000 --> 12:02.550 All we're doing right now is setting their enabled status based on what's selected. 12:02.550 --> 12:08.430 But now we need to actually make these buttons do something when we click on them. 12:09.020 --> 12:10.460 And we'll do that next. 12:11.270 --> 12:12.230 Excellent job. 12:12.230 --> 12:14.060 I'll see you in the next video.