WEBVTT 00:07.160 --> 00:07.760 All right. 00:07.760 --> 00:15.920 So now that we know when an effect is applied and we have the ability to get the asset tags for that 00:15.920 --> 00:21.050 effect and we want those tags to be broadcast over to the widget controller. 00:21.050 --> 00:22.470 We need a delegate. 00:22.490 --> 00:26.660 So I'd like to make a delegate for broadcasting the asset tags. 00:27.080 --> 00:32.450 Let's go into aura ability system components and make that delegate. 00:32.900 --> 00:37.250 Now, I don't plan on binding this from Blueprint. 00:37.400 --> 00:39.940 Our widgets aren't going to bind to this delegate. 00:39.950 --> 00:43.820 It's our widget controller that's going to bind to this delegate. 00:43.820 --> 00:50.060 So what I'm going to do is declare a multicast delegate. 00:50.090 --> 00:52.130 That's not dynamic. 00:52.930 --> 00:55.420 And it's going to have one param. 00:56.290 --> 01:04.930 And that param is going to be the asset tag or if we'd like the gameplay tag container with all the 01:04.930 --> 01:07.390 asset tags, it's really up to us. 01:07.510 --> 01:16.150 Now I'm going to call this F effect asset tags and our single parameter. 01:16.180 --> 01:20.890 Again, it could be a gameplay tag or it could be a gameplay tag container. 01:20.920 --> 01:23.910 I'm going to use gameplay tag container. 01:23.920 --> 01:27.550 So we're going to have a gameplay tag container. 01:27.760 --> 01:32.020 We'll go ahead and make it a const f gameplay tag container reference. 01:32.290 --> 01:39.430 And as we've seen with declare multicast delegate, we don't put the name of this parameter. 01:39.430 --> 01:45.160 We don't say comma followed by tag container or anything like that. 01:45.160 --> 01:55.100 But sometimes what I've seen and this can be a little helpful is making a comment here, an inline comment 01:55.280 --> 02:01.400 to sort of hint about what this is so we could say asset tags. 02:02.210 --> 02:09.170 And so even though that this comment does nothing to the code, it tells us when we look at it, that 02:09.170 --> 02:10.790 that's what this tag container is. 02:10.790 --> 02:12.200 It's the asset tags. 02:12.230 --> 02:15.890 Now, our ability system component needs this delegate. 02:15.890 --> 02:21.650 It needs to be able to broadcast the delegate and our widget controller needs to be able to bind to 02:21.650 --> 02:21.800 it. 02:21.800 --> 02:23.540 So we need to make this public. 02:23.540 --> 02:30.920 So in the public section, we're going to have our effect asset tags and we're going to call this effect 02:30.920 --> 02:34.160 asset tags and we're going to broadcast it. 02:34.160 --> 02:40.460 Now, what we can do if we like, is we can broadcast it here, in effect applied because we know this 02:40.460 --> 02:44.570 gets called and we have our asset tags, we have the tag container. 02:44.570 --> 02:55.540 So all we need to do here is just say effect asset tags, dot broadcast and pass in tag container just 02:55.540 --> 02:56.410 like that. 02:56.560 --> 03:05.020 And then any class who binds to our effect asset tags delegate will receive a tag container filled with 03:05.020 --> 03:06.340 the asset tags. 03:06.490 --> 03:07.720 Pretty simple. 03:07.810 --> 03:15.280 So really quickly to test this out, what we can do is we can go into our overlay widget controller 03:15.280 --> 03:18.670 and bind to effect asset tags if we like. 03:19.330 --> 03:20.980 So let's do it. 03:20.980 --> 03:26.350 We'll go into UI widget controller and overlay widget controller. 03:26.590 --> 03:27.550 But you know what? 03:27.550 --> 03:30.520 I'm going to go into the CPP file directly. 03:31.610 --> 03:39.500 So overlay widget controller TCP and here in bind callbacks to dependencies, I'd like to get our ability 03:39.530 --> 03:46.400 system component and we know that this is a ability system component, but we want the aura ability 03:46.400 --> 03:47.530 system component. 03:47.540 --> 03:54.320 So I'm going to cast to you aura, ability, system component, our ability system component. 03:54.320 --> 04:00.830 And using this, I'm going to get that F effect asset tags called effect asset tags. 04:01.250 --> 04:07.580 Now we know if we're going to bind to this delegate that we need a callback function, right? 04:07.610 --> 04:08.960 Well, not necessarily. 04:08.960 --> 04:14.710 If we hit Dot, we have a lot of options here and one of them is to add a lambda. 04:14.720 --> 04:18.290 Now, a lambda is an anonymous function. 04:18.290 --> 04:19.550 It doesn't have a name. 04:19.550 --> 04:21.770 It doesn't get declared anywhere. 04:21.770 --> 04:23.660 It's not a member function. 04:23.660 --> 04:25.790 It's just a function. 04:25.790 --> 04:33.980 And add lambda lets us define right here in the parentheses whatever functionality we want. 04:34.010 --> 04:37.010 Called in response to the delegate broadcast. 04:37.160 --> 04:39.410 A lambda looks like this. 04:39.410 --> 04:43.400 I'm going to hit enter a couple times and just put it right here. 04:43.400 --> 04:50.180 In fact, I'll go ahead and put my semicolon there and right here this is inside the parentheses to 04:50.180 --> 04:53.510 add Lambda ad lambda requires a lambda. 04:53.510 --> 04:55.670 We're going to make a lambda here. 04:55.670 --> 05:03.680 So first we put square brackets, then we put parentheses and then we put curly brackets. 05:04.070 --> 05:08.180 Okay, so this is the signature for a lambda. 05:08.180 --> 05:13.490 But if we bind anything to a delegate, it needs that signature. 05:13.490 --> 05:18.830 It needs the signature of a function that can take an gameplay tag container. 05:19.100 --> 05:22.640 Well, this lambda has parentheses. 05:22.640 --> 05:25.640 That's where the input parameter list goes. 05:25.640 --> 05:36.080 So we can put a const f gameplay tag container reference and we can call this asset tags. 05:36.430 --> 05:38.180 Doesn't matter what we call it. 05:38.180 --> 05:42.590 So now we have a lambda which is an anonymous function. 05:42.590 --> 05:50.600 And when the broadcast happens for this delegate, this lambda will be called and it has an input parameter 05:50.600 --> 05:53.900 called asset tags, it will receive that from the delegate. 05:53.900 --> 06:01.850 And what happens when it gets called whatever we put in the body here in our curly brackets, I'm going 06:01.850 --> 06:06.020 to put them on a new line to make this a little easier to read. 06:06.050 --> 06:08.530 And we can define what happens here. 06:08.540 --> 06:11.330 So what do we want to happen? 06:11.330 --> 06:11.650 Right. 06:11.660 --> 06:19.370 Because we've just now bound a lambda to affect asset tags on the ability system component. 06:19.400 --> 06:23.300 Well, why don't we just print a debug message and make sure it works? 06:23.300 --> 06:30.710 So back here in aura ability system component, I think we're done with this debug message, but what 06:30.710 --> 06:34.680 I'd like to do is copy it or rather control X to cut it. 06:34.680 --> 06:40.830 So now our ability system component is not doing any debug messages, it's just broadcasting a delegate. 06:40.830 --> 06:47.100 But now our widget controller has a lambda that will fire off in response to that delegate. 06:47.100 --> 06:52.920 Well, I'm going to control V right here and we can paste this code in where we can loop through the 06:52.920 --> 06:53.970 tag container. 06:53.970 --> 06:58.500 Now here inside the lambda, it's going to receive asset tags. 06:58.500 --> 07:00.000 That's the tag container. 07:00.000 --> 07:02.340 So that's what we have to loop through here. 07:02.340 --> 07:09.630 So we have a for loop looping through all the tags in the asset tags container and we don't need this 07:09.630 --> 07:10.530 comment. 07:11.190 --> 07:14.160 And well, we know what these two lines do. 07:14.160 --> 07:21.810 They take each tag in asset tags and add an on screen debug message basically the same thing as we were 07:21.810 --> 07:22.860 doing before. 07:23.070 --> 07:29.550 So the difference here now is that the ability system component will broadcast this delegate in response 07:29.550 --> 07:32.430 to having any effect applied to it. 07:32.580 --> 07:39.330 And it's going to send that tag container and then it's the widget controller that's going to parse 07:39.330 --> 07:39.750 the data. 07:39.750 --> 07:43.860 It's going to loop through the tag container and print it all to the screen. 07:43.860 --> 07:48.960 So if we can run this and it works, then that's actually really cool, right? 07:48.960 --> 07:55.500 Because this means we don't have to go and declare callback functions for all the delegates that we 07:55.500 --> 07:56.760 want to bind to. 07:56.790 --> 07:57.390 Right. 07:57.390 --> 07:59.940 This makes things a little bit simpler. 08:00.030 --> 08:04.770 I mean, look at all these callbacks we had to make for all of these delegates. 08:04.770 --> 08:07.490 What if we could just use lambdas for all of those? 08:07.500 --> 08:09.600 Well, let's make sure this works first. 08:09.600 --> 08:10.080 Okay. 08:10.080 --> 08:15.630 Let's go ahead and hit debug and see if we can get some messages printed to the screen. 08:15.900 --> 08:16.440 Okay. 08:16.440 --> 08:17.400 So we're back. 08:17.400 --> 08:23.040 I'm going to go ahead and let it open up my gameplay effects just to make sure our potion mana gameplay 08:23.040 --> 08:30.240 effect has two tags in its asset tags potion Heal has one and Crystal Heal has one. 08:30.240 --> 08:31.140 So let's press. 08:31.350 --> 08:33.600 Play and get a crystal and look at that. 08:33.600 --> 08:34.670 It's working. 08:34.680 --> 08:37.680 Our lambdas are working. 08:38.360 --> 08:39.590 How about that? 08:39.980 --> 08:41.240 This is great. 08:41.270 --> 08:45.860 Now, if you're skeptical, you can place a breakpoint here. 08:46.010 --> 08:47.470 So I got a breakpoint. 08:47.480 --> 08:50.150 I'm going to press play and pick up the potion. 08:50.150 --> 08:53.660 And look, the breakpoint works even in a lambda. 08:53.660 --> 09:01.550 So a lambda is one of those tools in C plus plus that we have at our disposal that allows us to kind 09:01.550 --> 09:07.430 of avoid having to create a bunch of member functions, especially for things that are simple, right? 09:07.430 --> 09:13.730 If we're going to bind a callback to a delegate and it's pretty simple, there's really no point in 09:13.730 --> 09:15.980 creating a whole callback function for it. 09:16.010 --> 09:20.780 A lambda is cleaner sometimes and it's also kind of fancy, right? 09:20.780 --> 09:21.740 It's kind of cool. 09:21.740 --> 09:26.180 So now that we know how to do that, we just have one more tool in our tool belt. 09:26.180 --> 09:31.700 And if you already knew about Lambdas, maybe you've been using this already, then you already have 09:31.700 --> 09:32.900 this tool in your toolbox. 09:32.900 --> 09:37.370 And I think that's great that you've been taking advantage of it. 09:37.700 --> 09:39.500 So excellent job. 09:39.500 --> 09:42.260 We're now one step closer to our goal. 09:42.260 --> 09:48.860 We have those asset tags here in our widget controller overlay widget controller. 09:48.890 --> 09:54.500 The next step is to get them to the widgets themselves so we can do that next. 09:54.500 --> 09:58.340 In the meantime, I'm going to go ahead and hit the stop button. 09:58.430 --> 10:02.990 We're done with this and I'll see you in the next video.