1
00:00:00,570 --> 00:00:03,100
Cradle is an amazingly
flexible build tool, and

2
00:00:03,100 --> 00:00:06,060
it's jam packed with
all sorts of features.

3
00:00:06,060 --> 00:00:09,070
Build tools are used to automate
the process of packaging up and

4
00:00:09,070 --> 00:00:11,420
shipping your code to your users.

5
00:00:11,420 --> 00:00:14,160
There are a lot of tasks that typically
happen when you want to build

6
00:00:14,160 --> 00:00:15,310
your project.

7
00:00:15,310 --> 00:00:18,610
Tasks all the way from running unit tests
to making sure that everything's working

8
00:00:18,610 --> 00:00:22,750
as intended, to creating JARs
with version specific metadata.

9
00:00:22,750 --> 00:00:26,780
Now over time developers have learned
that having a standardized build tool

10
00:00:26,780 --> 00:00:30,600
is an essential part of the development
flow, especially when working with teams.

11
00:00:31,790 --> 00:00:34,385
You might have heard of some other
build tools such as Maven or Ant,

12
00:00:34,385 --> 00:00:37,810
Gradle does a great job of interacting
with those other build tools.

13
00:00:39,160 --> 00:00:43,370
We are going to be narrowing the scope of
this workshop to managing dependencies.

14
00:00:43,370 --> 00:00:46,620
There's a lot of ground to cover here,
so if you would like us to cover more,

15
00:00:46,620 --> 00:00:48,960
check the teacher's notes to
see how to make requests and

16
00:00:48,960 --> 00:00:50,749
what other requests have been
made by your fellow students.

17
00:00:52,970 --> 00:00:55,760
Gradle exposes a domain-specific language,
or

18
00:00:55,760 --> 00:01:00,400
DSL, that is based heavily on
the Groovy programming language.

19
00:01:00,400 --> 00:01:03,140
Groovy is a dynamic scripting
language that runs on the JVM.

20
00:01:03,140 --> 00:01:07,560
You'll find it to be very expressive and
legible, and

21
00:01:07,560 --> 00:01:10,560
probably quite familiar as
it's very similar to Java.

22
00:01:12,340 --> 00:01:15,920
Other build tools have embraced
XML as their primary language.

23
00:01:15,920 --> 00:01:17,800
By using the Gradle based DSL,

24
00:01:17,800 --> 00:01:21,060
it encourages everyone to get
involved in scripting of the tasks.

25
00:01:22,240 --> 00:01:26,910
Gradle has an opinionated way of how
things should be done and laid out.

26
00:01:26,910 --> 00:01:30,660
If you follow its conventions,
you'll find things very easy to configure.

27
00:01:30,660 --> 00:01:33,230
And it also provides an easy
path to customize it

28
00:01:33,230 --> 00:01:36,900
outside of the suggested patterns,
it's the best of both worlds.

29
00:01:36,900 --> 00:01:39,205
Let's take a quick look at how
to get started using Gradle.

30
00:01:39,205 --> 00:01:44,110
Okay, so the easiest way to
create a new project that is all

31
00:01:44,110 --> 00:01:48,130
Gradle ready is by using
the IntelliJ Gradle template.

32
00:01:48,130 --> 00:01:50,970
Let's create a new project that
will exercise the comma separated

33
00:01:50,970 --> 00:01:52,959
value library as a way
of testing the flow out.

34
00:01:52,959 --> 00:01:56,543
So let's make a little mock
project that gathers reviews and

35
00:01:56,543 --> 00:02:00,720
then exports those reviews
to spreadsheet format, CSV.

36
00:02:00,720 --> 00:02:03,330
First let's make a new project, so
we'll click Create New Project.

37
00:02:03,330 --> 00:02:07,240
And then you'll see over here on the left,
normally we leave this on Java, but

38
00:02:07,240 --> 00:02:09,650
let's scroll down here to
where it's says Gradle.

39
00:02:09,650 --> 00:02:13,490
So we'll do this, let's choose that and
we'll just go ahead leave

40
00:02:13,490 --> 00:02:16,180
the language that we're writing in is
Java, so we will go ahead and click next.

41
00:02:17,680 --> 00:02:19,870
Now we'll will get some
options presented to us and

42
00:02:19,870 --> 00:02:22,810
unfortunately there's not
much direction here, huh?

43
00:02:22,810 --> 00:02:26,040
Now remember that Gradle is first and
foremost, it's a build tool.

44
00:02:26,040 --> 00:02:31,740
So these prompts are specifically asking
what you want to publish our project as.

45
00:02:31,740 --> 00:02:35,540
So group ID here follows the same
packaging names that we've been doing

46
00:02:35,540 --> 00:02:37,140
with normal packages.

47
00:02:37,140 --> 00:02:40,390
So, this is kind of like what we
want to say in our base packages.

48
00:02:40,390 --> 00:02:42,900
So let's go ahead and let's,
we're making the review app, right?

49
00:02:42,900 --> 00:02:47,440
So we'll do com.teamtreehouse, and let's
put it in the package called reviews.

50
00:02:48,680 --> 00:02:51,480
Artifact idea here is
what you want to name

51
00:02:51,480 --> 00:02:53,650
the JAR file when it gets created, right?

52
00:02:53,650 --> 00:02:56,570
When it gets published,
what do you want to JAR file to be named?

53
00:02:56,570 --> 00:03:00,330
So, it probably makes sense for
us to call it reviews.jar.

54
00:03:00,330 --> 00:03:01,140
So let's call it reviews.

55
00:03:02,735 --> 00:03:05,400
Cool, the version here is something that
we'll talk about more in the future.

56
00:03:05,400 --> 00:03:07,750
For now,
let's just leave it as its default.

57
00:03:07,750 --> 00:03:09,260
So we'll click next.

58
00:03:09,260 --> 00:03:12,450
Okay, so
now we have some more Gradle IDE options.

59
00:03:12,450 --> 00:03:16,430
If we want to check the box here for auto
import, every time, what that means is

60
00:03:16,430 --> 00:03:19,410
every time that we change the file,
the project will automatically refresh.

61
00:03:19,410 --> 00:03:20,890
We'll talk more about this here in a bit,

62
00:03:20,890 --> 00:03:23,610
it will just automatically do it
without us specifically forcing it.

63
00:03:23,610 --> 00:03:27,360
I want to show you both ways, but for
now, let's just leave that box unchecked.

64
00:03:27,360 --> 00:03:29,370
Now let's check this one, though,

65
00:03:29,370 --> 00:03:32,880
this create directories for
empty content roots automatically.

66
00:03:32,880 --> 00:03:37,150
One of the specific ways that Gradle
is opinionated is the way that

67
00:03:37,150 --> 00:03:41,420
it by default expects your projects to be
laid out structure wise, like folders and

68
00:03:41,420 --> 00:03:42,470
directories.

69
00:03:42,470 --> 00:03:45,610
It's a little bit different actually than
what we've been using in the past, so

70
00:03:45,610 --> 00:03:48,517
I want to check this and we'll make sure
that we are going to set up the Gradle

71
00:03:48,517 --> 00:03:51,409
defaults in the projects, so we can
kinda walk through them a little bit.

72
00:03:51,409 --> 00:03:54,831
You'll find that most Gradle projects and
Maven projects for that matter,

73
00:03:54,831 --> 00:03:57,180
actually follow the same directory layout.

74
00:03:57,180 --> 00:04:01,455
Okay, so let's click next,
and finally some normal

75
00:04:01,455 --> 00:04:05,680
IntelliJ questions that happen here, and
the defaults are pretty sane, right?

76
00:04:05,680 --> 00:04:09,400
The project name is gonna be reviews, and
we're gonna drop it in the same location.

77
00:04:09,400 --> 00:04:10,580
So let's click finish.

78
00:04:12,175 --> 00:04:14,510
Okay, and if this is the first
time that gradle is being run,

79
00:04:14,510 --> 00:04:16,325
you'll see some downloading happen.

80
00:04:16,325 --> 00:04:19,980
IntelliJ will actually go out and
download Gradle and then run some things.

81
00:04:19,980 --> 00:04:22,970
I've already run this Gradle before on
this machine so it was pretty fast.

82
00:04:22,970 --> 00:04:25,236
It might take a bit longer on yours.

83
00:04:25,236 --> 00:04:28,410
So, once the download's done,
it will go and

84
00:04:28,410 --> 00:04:32,340
create all the default files and
folders that are expected by Gradle.

85
00:04:32,340 --> 00:04:34,510
So let's go ahead and
open up the project structure over here.

86
00:04:34,510 --> 00:04:37,520
Let's open this up,
our reviews project, and

87
00:04:37,520 --> 00:04:40,580
it ended up creating this build script for
us which is called build.gradle.

88
00:04:40,580 --> 00:04:45,190
But first let's take a look here
under the source directory, this SRC.

89
00:04:45,190 --> 00:04:47,850
So this is split up a little bit
differently than we have seen in

90
00:04:47,850 --> 00:04:48,360
the past, right?

91
00:04:48,360 --> 00:04:51,340
Before we just had source and
maybe it was marked as a source's root.

92
00:04:51,340 --> 00:04:53,520
So the source's root is
a little bit deeper in here.

93
00:04:53,520 --> 00:04:55,899
Under main, you'll see that
the source's root is Java and

94
00:04:55,899 --> 00:04:59,740
then there's also a little resources
thing that's set up for us which is nice.

95
00:04:59,740 --> 00:05:02,280
And there's also a test directory, and
then there's also another thing called

96
00:05:02,280 --> 00:05:04,850
Java here, and
it's marked as the test route.

97
00:05:04,850 --> 00:05:07,640
So it's a little bit different of
a layout, and this is definitely the Maven

98
00:05:07,640 --> 00:05:11,140
style of doing things, but
Gradle follows this by default.

99
00:05:11,140 --> 00:05:13,300
So let's open up that build
script that it built for us, and

100
00:05:13,300 --> 00:05:15,144
it's called build.gradle.

101
00:05:16,380 --> 00:05:19,770
There's an option here that will
allow us to automatically get

102
00:05:19,770 --> 00:05:21,550
suggestions from the IDE.

103
00:05:21,550 --> 00:05:23,590
So let's go ahead,
let's say okay apply this suggestion.

104
00:05:25,200 --> 00:05:27,700
You might see this message,
lets feel free to click away from it.

105
00:05:28,840 --> 00:05:31,120
If you can look in here you see that
this is the group that we define.

106
00:05:31,120 --> 00:05:33,110
Remember, we said com.treehouse.reviews.

107
00:05:33,110 --> 00:05:36,310
And this is the version that was
there at the bottom, so that's there.

108
00:05:36,310 --> 00:05:40,710
There's also this thing here called
a plug in, and it's got the Java plug in.

109
00:05:40,710 --> 00:05:43,030
And this is what's defining
the layout of the folders and

110
00:05:43,030 --> 00:05:45,210
how to package things up and etc.

111
00:05:45,210 --> 00:05:47,700
Now, because we don't have
anything really defined in here,

112
00:05:47,700 --> 00:05:49,180
it's just using the defaults, right?

113
00:05:49,180 --> 00:05:51,400
So we could definitely
override the defaults but

114
00:05:51,400 --> 00:05:52,960
there's nothing that we need to here.

115
00:05:52,960 --> 00:05:55,660
So, there's different types of plugins for
this.

116
00:05:55,660 --> 00:05:58,510
There's one for Android and
it does all the building, packaging and

117
00:05:58,510 --> 00:06:01,500
versioning of making all of
that Android magic happen.

118
00:06:01,500 --> 00:06:04,360
Also what I want to point out here
is while this looks pretty clear,

119
00:06:04,360 --> 00:06:07,240
it's actually the Groovy
programming language.

120
00:06:07,240 --> 00:06:09,430
It's pretty clear why
they choose that right?

121
00:06:09,430 --> 00:06:12,040
This is really nice looking,
it's pretty easy to read.

122
00:06:12,040 --> 00:06:15,050
But we aren't going to get
into too much customization,

123
00:06:15,050 --> 00:06:17,920
I did want to point out that these
are just methods sitting on the API.

124
00:06:17,920 --> 00:06:21,550
And this build.gradle file here
is in the project context.

125
00:06:22,650 --> 00:06:27,320
So this repositories here,
this is a method defined on the project.

126
00:06:27,320 --> 00:06:30,340
And it takes a closure,
this is a closure here,

127
00:06:30,340 --> 00:06:32,800
as a parameter in the groovy language.

128
00:06:32,800 --> 00:06:35,880
So you could look at the API and
see what the repositories were.

129
00:06:35,880 --> 00:06:38,850
You could find it in the reference
documentation if you wanted to do more.

130
00:06:38,850 --> 00:06:41,500
I've added some in the teacher's notes,
so go ahead and click through there and

131
00:06:41,500 --> 00:06:42,630
see if you want it.

132
00:06:42,630 --> 00:06:46,110
>> Now, don't worry if the syntax is
weird when you actually can't read it.

133
00:06:46,110 --> 00:06:48,310
You will understand it if
we spend some time on it.

134
00:06:48,310 --> 00:06:51,710
For now though,
I just want you to appreciate the brevity.

135
00:06:51,710 --> 00:06:54,320
One more cool thing that I wanted
to point out while we're here

136
00:06:54,320 --> 00:06:56,400
is that in the base directory
here there's this file,

137
00:06:56,400 --> 00:06:59,790
there's these two files called gradlew and
gradlew.bat.

138
00:06:59,790 --> 00:07:01,770
This is the Gradle wrapper.

139
00:07:01,770 --> 00:07:04,820
It provides some incredible self
installing set up of Gradle for

140
00:07:04,820 --> 00:07:06,830
anybody who want's to get
their hands on your project.

141
00:07:06,830 --> 00:07:10,414
And might not have IntelliJ idea or
Gradle installed.

142
00:07:10,414 --> 00:07:13,440
[LAUGH] It's a pretty genius way of
making sure that everyone can build and

143
00:07:13,440 --> 00:07:15,680
test your project the same way.

144
00:07:15,680 --> 00:07:18,440
You just download the code,
and you kick off the script,

145
00:07:18,440 --> 00:07:20,750
and Gradle installs
itself should it need to.

146
00:07:20,750 --> 00:07:22,350
It's pretty clever, right?

147
00:07:22,350 --> 00:07:24,250
I'll show off some more command
line fun here in a bit.

148
00:07:25,400 --> 00:07:28,050
Awesome, now that we got
your environment all set up,

149
00:07:28,050 --> 00:07:29,640
let's get on to the task at hand.

150
00:07:30,670 --> 00:07:33,780
Oh, one thing I wanted to add here,
both Gradle and

151
00:07:33,780 --> 00:07:37,140
the Groovy Language are open source,
pretty cool right?

152
00:07:37,140 --> 00:07:41,150
Again, don't worry if you didn't fully
understand the scripting language

153
00:07:41,150 --> 00:07:42,190
in the build script.

154
00:07:42,190 --> 00:07:44,080
We won't be needing it just yet.

155
00:07:44,080 --> 00:07:47,260
And I'll cover what you need
to know as we encounter it.

156
00:07:47,260 --> 00:07:51,230
If you'd like to learn more about Groovy,
as always, check the teacher's notes.

157
00:07:51,230 --> 00:07:53,880
All right, let's get to managing
those pesky dependencies