1
00:00:02,380 --> 00:00:08,170
So we had a look at a lot of decorators how you work with them how you can configure them how you can

2
00:00:08,740 --> 00:00:14,830
do stuff with them what you can do with them and this hopefully shows you the complexity but also the

3
00:00:14,830 --> 00:00:19,000
power of decorators and how you can think about them how you can use them.

4
00:00:19,150 --> 00:00:25,810
Now you're not only able to create your own decorators there also is a rich ecosystem out there of packages

5
00:00:25,810 --> 00:00:30,670
and frameworks that rely on decorators for example CLOs and validator.

6
00:00:30,730 --> 00:00:37,600
If you search for T S Class validator you find a package which basically has a more elaborate implementation

7
00:00:37,810 --> 00:00:40,240
of our own custom validation logic.

8
00:00:40,240 --> 00:00:46,780
We worked on this package can be added to any project you're working on and then you can simply import

9
00:00:46,780 --> 00:00:52,360
a bunch of decorators or decorator factories as you can see since we execute them here at home to your

10
00:00:52,360 --> 00:00:57,630
properties with or without some extra configuration depending on the validator it is.

11
00:00:57,750 --> 00:01:03,370
And behind the scenes this will manage such a registry you could say such a configuration object in

12
00:01:03,370 --> 00:01:09,670
the end store your validator is set up for the different properties in your different classes and then

13
00:01:09,820 --> 00:01:16,000
give you validate method which you also import from the package which you can execute and pass your

14
00:01:16,000 --> 00:01:20,590
object to to apply all the validation logic you set up in the class.

15
00:01:20,590 --> 00:01:27,040
So it's basically doing what we just did just with more validators and with all the heavy lifting done

16
00:01:27,040 --> 00:01:27,600
for you.

17
00:01:27,850 --> 00:01:32,590
But of course it helps to understand how it is generally works since we built it on our own here in

18
00:01:32,590 --> 00:01:34,990
a more nave version.

19
00:01:35,050 --> 00:01:40,840
Now besides this package of course we also have angular for example angular is a framework which I mentioned

20
00:01:40,870 --> 00:01:47,410
early already which heavily relies on decorators like this component decorator which allows you to create

21
00:01:47,410 --> 00:01:54,220
some wear which allows you to assign some dynamic HDL code which taps into properties of your classes

22
00:01:54,220 --> 00:02:00,160
as well with a special syntax added by angular to then render some dynamic content onto the screen.

23
00:02:00,220 --> 00:02:05,650
So here angular does more than just offer these decorators but the decorators are a core part of angular

24
00:02:06,370 --> 00:02:13,180
and last but not least I also want to show you nest J.S. nest J as is a service side javascript framework

25
00:02:13,180 --> 00:02:20,010
for note J.S. which also heavily utilizes TypeScript and this also embraces decorators.

26
00:02:20,140 --> 00:02:27,040
Are you use decorators to define controllers and routs the methods which users have to use on their

27
00:02:27,040 --> 00:02:33,910
age the p requests to trigger certain functions and also a lot of other decorators you can use to extract

28
00:02:33,940 --> 00:02:36,940
data from incoming requests and so on.

29
00:02:36,940 --> 00:02:42,910
So here this framework also again offers all these decorators for you so that you can just add them

30
00:02:42,940 --> 00:02:49,660
to your properties to your methods to your classes and add extra functionality which the framework then

31
00:02:49,660 --> 00:02:53,250
in turn also takes into account when it executes your code.

32
00:02:53,260 --> 00:03:00,670
So here again decorators are used for meta programming to add extra configuration extra logic which

33
00:03:00,670 --> 00:03:07,930
then is taken into account by in this case the code of the framework which executes your code or which

34
00:03:07,930 --> 00:03:11,110
works together with your code and that's it.

35
00:03:11,110 --> 00:03:16,510
For decorators this hopefully gives you a good overview of what you can do with decorators why they

36
00:03:16,510 --> 00:03:19,420
can be very helpful and how they generally work.