WEBVTT 00:06.880 --> 00:08.100 Welcome back. 00:08.110 --> 00:14.370 So now we're successfully finding the data table row associated with any given tag. 00:14.380 --> 00:21.880 We now would like to broadcast this up to widgets that can bind to some kind of delegate and receive 00:21.880 --> 00:28.480 that row and then show something in the HUD using assets from that data table row. 00:28.570 --> 00:32.350 So we're going to want some kind of delegate. 00:33.050 --> 00:35.870 So let's go back to overlay widget controllers. 00:36.290 --> 00:41.420 I'm going to move it over to the right here and we're going to make a delegate up here at the top and 00:41.420 --> 00:47.120 we're going to use one delegate for all messages because we can just broadcast a row. 00:47.150 --> 00:48.300 That's all we need. 00:48.320 --> 00:54.570 The row has all the information to identify that specific bundle of data. 00:54.590 --> 00:56.390 It has a gameplay tag. 00:56.390 --> 00:57.790 It has the message. 00:57.800 --> 01:03.160 All of this stuff is in the row itself, so we could just use one row to rule them all. 01:03.170 --> 01:08.930 So I'd like to make a dynamic multicast delegate one param just like these. 01:10.340 --> 01:22.130 Only we're going to call this delegate signature F message widget row signature and it's going to broadcast 01:22.130 --> 01:25.490 a value of type f ui widget row. 01:25.490 --> 01:33.060 So we'll put that there and we'll just call it row now f ui Widget row is undefined right here and we're 01:33.060 --> 01:39.150 not going to use a pointer, we're just going to use an f UI widget row, which means we need to define 01:39.150 --> 01:42.060 this struct before we define the delegate. 01:42.060 --> 01:50.010 So we can just cut the entire struct definition with control x and move it up to above everything. 01:50.010 --> 01:52.860 I'm just going to put it just below the includes there. 01:52.860 --> 01:55.080 And now it's defined. 01:55.410 --> 02:02.100 Now as soon as we move it up here, well now we're using some types in the struct that are not defined 02:02.100 --> 02:06.180 yet and these ones we can forward declare. 02:06.180 --> 02:11.640 So we're using or user widget, that's really the only one we can forward declare this. 02:11.640 --> 02:15.630 I'm going to go ahead and forward declare it just right here and now. 02:15.630 --> 02:19.710 If I compile this, then I get a successful compile. 02:19.710 --> 02:23.610 So now we're all good on our types. 02:23.790 --> 02:30.270 So now that we have this signature, let's make a member variable of this type right here just below 02:30.270 --> 02:31.230 the others. 02:31.230 --> 02:36.750 So I'm going to call this method message widget row delegate. 02:38.130 --> 02:43.980 Or we could just call it message Widget row doesn't matter and I'm going to make it blueprint assignable, 02:43.980 --> 02:46.110 so I'll put that uproperty there. 02:46.110 --> 02:52.350 And for the category, let's give it gas with the pipe symbol and then messages. 02:52.350 --> 02:54.720 And now we can broadcast this delegate. 02:54.870 --> 02:56.550 So we're going to do that. 02:56.580 --> 03:02.790 Now, I know you're probably thinking if we just have one delegate for all messages, why can't we just 03:02.790 --> 03:05.490 have one delegate for all attributes? 03:05.490 --> 03:12.840 And the answer is you actually could we could just have an F on attribute change signature as they're 03:12.840 --> 03:20.280 all floats anyway, so we'll probably have some refactoring to do that in the near future. 03:20.280 --> 03:25.800 But for the task at hand, we just want to broadcast a UI widget row. 03:25.800 --> 03:32.250 So now that we have this delegate, let's go back into our lambda and just after getting that row we 03:32.250 --> 03:40.430 can take our message widget row, delegate, we can call broadcast and we can broadcast the row. 03:40.580 --> 03:45.890 Now we know that this is a pointer, so we're going to have to dereference the pointer. 03:45.890 --> 03:51.350 So we'll just say star row and the reference it just like that. 03:51.350 --> 03:55.940 Now you might be thinking, isn't there a problem with this system? 03:55.940 --> 04:01.990 What if asset tags has a game play tag that is not a message tag, right? 04:02.000 --> 04:06.140 What if it's some other tag we choose to use for something else? 04:06.140 --> 04:07.760 For the game play effect. 04:07.790 --> 04:12.380 We don't want to restrict our asset tags container to just message tags. 04:12.380 --> 04:12.980 Right. 04:13.530 --> 04:20.610 So how do we enforce or rather restrict this functionality to only when we have a message tag? 04:21.210 --> 04:24.960 Well, tags are super useful and we can do things like that. 04:25.200 --> 04:28.680 The gameplay tag has some functions. 04:28.680 --> 04:36.060 Let's type F gameplay tag double colon and search for match and notice. 04:36.060 --> 04:40.740 We have a bunch of functions that start with match such as matches tag. 04:40.860 --> 04:47.340 Now this is not a static function, but I just wrote this so that I can right click on matches tag and 04:47.340 --> 04:48.690 go to its definition. 04:48.690 --> 04:51.210 So go to declaration or usages. 04:51.300 --> 04:52.170 Here it is. 04:52.170 --> 04:58.440 We can see what it does, but let's control O and find it here in the header file. 04:58.440 --> 05:00.510 It's in gameplay tag container. 05:00.690 --> 05:07.040 And what we do is we call this function on a gameplay tag passing in another gameplay tag. 05:07.050 --> 05:10.890 So it says determine if this tag matches tag to check. 05:10.920 --> 05:21.070 That's what we pass in expanding our parent tags and it says a .1. matches tag A will return. 05:21.070 --> 05:30.760 True if a dot matches tag a dot one will return false and it says if tag to check is not valid, it 05:30.760 --> 05:32.050 will always return false. 05:32.050 --> 05:39.010 So if this explanation seems a little confusing, let's copy this line and come back to the widget controller 05:39.130 --> 05:43.750 and we'll make a little comment here and paste that in. 05:43.750 --> 05:46.990 So a dot one matches tag A will return. 05:46.990 --> 05:47.800 True. 05:48.010 --> 05:48.970 What does that mean? 05:48.970 --> 05:50.830 Well, let's take our tag. 05:52.640 --> 05:55.400 Use Dot and we'll call matches tag. 05:55.400 --> 05:56.090 Okay. 05:57.020 --> 06:01.610 Now we want to match against the message tag. 06:01.610 --> 06:08.210 And if a tag exists in our project, it exists in one of our config files. 06:08.240 --> 06:19.160 Then we can get the tag with the static function f gameplay tag colon colon request gameplay tag which 06:19.160 --> 06:20.830 requires an F name. 06:20.840 --> 06:25.130 So we're going to say f name and then we say the tag we want. 06:25.160 --> 06:27.320 We want a message. 06:27.770 --> 06:30.650 So this returns a gameplay tag. 06:30.650 --> 06:31.520 We're going to store it. 06:31.520 --> 06:42.200 We're going to say F gameplay tag message tag and request gameplay tag has a bool called error if not 06:42.200 --> 06:44.210 found automatically set to true. 06:44.210 --> 06:50.810 So if we call this with a tag that does not exist already in our project, we can't see it in project 06:50.810 --> 06:51.470 settings. 06:51.470 --> 06:56.220 We'll get an error, but we can use message even though we have message. 06:56.220 --> 06:59.070 Dot health potion message dot mana potion. 06:59.070 --> 07:02.460 Well message is considered a tag as well. 07:02.730 --> 07:09.270 It's the top of that little hierarchy so we can call tag matches, tag and pass in a tag. 07:09.270 --> 07:11.040 We're going to pass in message tag. 07:11.550 --> 07:16.020 And now we have something more concrete for this explanation. 07:16.290 --> 07:19.650 So let's make this a little bit less confusing, shall we? 07:19.650 --> 07:22.560 Let's take a hypothetical example. 07:22.830 --> 07:29.910 Now we know that tag in asset tags could be one of those message tags in our project. 07:29.910 --> 07:33.990 So let's take the example where tag is equal to one of them. 07:33.990 --> 07:42.270 We'll say, for example, say that tag is message dot health potion. 07:42.750 --> 07:48.600 So here in this comment, we're going to replace a with message. 07:49.460 --> 07:51.860 And one with health potion. 07:53.020 --> 07:55.780 So here A is message. 07:57.140 --> 08:00.170 And over here A is message. 08:00.290 --> 08:03.530 A one is message dot health potion. 08:05.000 --> 08:09.500 Now we have a more concrete example that kind of makes more sense. 08:09.530 --> 08:17.780 So in the case where tag is message dot health potion then for this function matches tag where tag is 08:17.780 --> 08:22.760 message dot health potion and message tag is just message. 08:22.940 --> 08:26.780 Then the comment says message dot health potion. 08:26.780 --> 08:27.260 Right. 08:27.260 --> 08:32.060 That's our tag calling matches tag with message passed in. 08:32.090 --> 08:33.410 That's what we're doing. 08:33.410 --> 08:35.540 It says that this will return true. 08:35.870 --> 08:45.500 However, if instead we had taken our message tag, which is just message and called matches tag passing 08:45.500 --> 08:50.380 in this tag message dot health potion that would return false. 08:50.390 --> 08:53.900 So that's how the matches tag function works. 08:54.080 --> 09:03.030 If we're taking a tag that has more chains of the hierarchy in the tag and we're seeing if it matches 09:03.060 --> 09:09.330 a tag that's less of those branches say message, then this would return. 09:09.330 --> 09:10.040 True. 09:10.050 --> 09:16.320 And that's exactly the behavior we want because we want to see if the tag is a message tag. 09:16.320 --> 09:20.220 We don't care what message as long as it is a message tag. 09:20.220 --> 09:26.160 If it's any other tag, say an ability tag, an input tag, any other kind of tag we define. 09:26.160 --> 09:31.200 We don't want to look for a widget row in our message widget data table. 09:31.200 --> 09:37.170 We only want to look for a row in the table if the tag is a message tag specifically. 09:37.320 --> 09:44.310 So we'll go ahead and keep that comment there just so we know what's going on and we can remove this 09:44.340 --> 09:48.660 onscreen debug message, I'm going to go ahead and remove those lines. 09:48.960 --> 09:51.120 And we have this expression here. 09:51.120 --> 09:52.440 We're calling matches tag. 09:52.440 --> 09:57.480 Now this returns a bool and it will be true if tag is a message tag. 09:57.480 --> 10:04.980 So what we'll do is we'll say if and then we'll place this expression in the if statement. 10:04.980 --> 10:11.520 I'm just going to drag it on in there and we'll only look for the row and make the broadcast if tag 10:11.520 --> 10:14.430 matches the message tag, which is just message. 10:14.430 --> 10:16.710 So I'm going to go ahead and put those lines in there. 10:18.580 --> 10:26.500 So now we won't even bother trying to find a row in our data table unless our tag that we're checking 10:26.500 --> 10:32.430 in asset tags has message as its root of the hierarchy. 10:32.440 --> 10:36.760 And one last thing this row pointer can be const. 10:37.570 --> 10:45.700 Okay, so now we have a broadcast and all we need to do is bind to this delegate. 10:45.730 --> 10:51.520 We're broadcasting in our widget so we can do that and test it out. 10:52.140 --> 10:54.480 So that's going to be your quest. 10:54.750 --> 10:57.330 I'd like you to receive the data table row. 10:57.360 --> 11:00.690 Do this in the widget Blueprint for the overlay. 11:00.720 --> 11:08.460 BP Overlay and bind an event to message widget row, delegate and print a debug string. 11:08.460 --> 11:12.540 Just make sure that that widget is receiving the delegate. 11:12.570 --> 11:15.860 Now choose the best place to do this. 11:15.870 --> 11:21.180 Make sure that that widget controller is set by the time you try to do this. 11:21.180 --> 11:22.970 So let's get this working. 11:22.980 --> 11:28.020 Make sure the print string says something related to the widget so we know that we're getting the actual 11:28.020 --> 11:30.930 string in the widget blueprint, so we know it's working. 11:30.930 --> 11:34.410 So pause the video and conquer this quest now. 11:37.610 --> 11:40.530 Okay, let's compile and launch. 11:40.550 --> 11:42.290 I'm going to run this in debug mode. 11:42.560 --> 11:47.140 And here in the editor, I'm just going to open my overlay widget. 11:47.150 --> 11:52.610 So let's go to Blueprints UI overlay and open up overlay. 11:52.610 --> 11:58.970 And here in the graph tab, I know that I can bind to the widget as soon as my widget controller has 11:58.970 --> 12:00.020 been set. 12:00.380 --> 12:08.450 Now things are starting to get a little more complicated here because I'm going to bind an event to 12:08.450 --> 12:14.540 the delegate, so I'm going to make a sequence here to organize things. 12:15.240 --> 12:19.010 So I'm going to move these nodes up and out of the way. 12:19.140 --> 12:20.940 Give them a reroute node there. 12:23.780 --> 12:29.510 And the next thing we're going to do is we're going to bind to the delegates on the widget controller. 12:29.510 --> 12:35.440 But remember, our widget controller is just a U object, so we need to cast it. 12:35.450 --> 12:38.270 So in fact, I'd like to do that first. 12:38.270 --> 12:41.690 So then one can be these nodes. 12:41.690 --> 12:45.200 But before I do that, I'm just going to cast my widget controller. 12:45.200 --> 12:45.770 Here it is. 12:45.770 --> 12:53.270 I'm going to duplicate this and cast to BP overlay widget controller, and I'm going to promote this 12:53.270 --> 12:54.020 to a variable. 12:54.020 --> 12:55.580 So hooking that up here. 12:56.830 --> 12:58.770 And promoting it to a variable. 12:58.780 --> 13:04.090 I'm going to call it BP overlay widget controller. 13:06.010 --> 13:08.020 So now we have that there. 13:08.930 --> 13:17.270 And after setting the widget controllers for the health globe and the Mana Globe, now we can take our 13:17.270 --> 13:19.430 BP overlay widget controller. 13:19.460 --> 13:27.080 I can drag off of it and I can type message widget and see I have my message widget row delegate. 13:27.080 --> 13:28.370 I can assign to that. 13:28.370 --> 13:30.140 I'm going to choose that. 13:30.140 --> 13:37.970 Add a pin to the sequence and bring it out and check this out as soon as this delegate gets broadcast. 13:38.000 --> 13:48.380 Here in WB Overlay, we have our event called in response but it receives this a UI widget row structure 13:48.380 --> 13:55.720 and we can drag off and we can even break this and we have access to all sorts of cool stuff here. 13:55.730 --> 14:01.700 Now I'd like to just make sure this is working by using a print string node and I'm going to take my 14:01.700 --> 14:10.260 message and just stick it in there so we can see the message that corresponds to the gameplay tag in 14:10.260 --> 14:11.850 the effect that was applied. 14:11.850 --> 14:13.890 So saving all. 14:13.890 --> 14:18.330 I'm going to pick up some things and see what we get printed to the screen. 14:18.840 --> 14:20.580 Picked up a health crystal. 14:20.580 --> 14:21.450 That looks great. 14:21.450 --> 14:23.160 Let's get a mana potion. 14:23.190 --> 14:23.850 Look at that. 14:23.850 --> 14:25.380 Picked up a mana potion. 14:26.040 --> 14:27.720 Picked up a health potion. 14:28.140 --> 14:29.820 Picked up a mana crystal. 14:29.820 --> 14:35.310 So we're getting the message from the data table. 14:35.730 --> 14:44.460 In fact, we're getting the entire data table row corresponding to whatever gameplay tag was there inside 14:44.460 --> 14:45.870 that gameplay effect. 14:45.870 --> 14:52.230 And the cool thing is we're looping through the gameplay tag container, so there could be multiple 14:52.230 --> 14:58.490 message tags if we really wanted to have multiple and I'm not going to show you that example. 14:58.500 --> 15:04.350 I'm sure you understand that you could just add to the asset tags for a gameplay effect. 15:04.350 --> 15:10.230 And because we're looping through, we would be broadcasting the delegate multiple times. 15:10.350 --> 15:18.600 So now that we know that our system is working, we know that we have access to the gameplay tag, the 15:18.600 --> 15:22.860 message, the widget, which we're not really setting the widget yet. 15:22.860 --> 15:26.710 It's just a widget class actually, because that's a T a subclass of. 15:26.740 --> 15:31.570 But we haven't set that in the data table for any of our tags, but we will. 15:31.570 --> 15:33.900 And then we also have the image as well. 15:33.910 --> 15:42.580 So we have a lot of information now that we can use to display any kind of message we want to the screen. 15:42.580 --> 15:45.460 So we're going to do that in the videos to come. 15:45.730 --> 15:48.730 So great job and I'll see you soon.