Heads up! To view this whole video, sign in with your Courses account or enroll in your free 7-day trial. Sign In Enroll
Preview
Start a free Courses trial
to watch this video
The first thing we need to do to prepare our app for release is remove any Log method calls. In this video we'll see how to easily do this with a tool called ProGuard.
ProGuard lines for copy/paste:
-assumenosideeffects class android.util.Log {
public static boolean isLoggable(java.lang.String, int);
public static int v(...);
public static int i(...);
public static int w(...);
public static int d(...);
public static int e(...);
}
Notes
If you are familiar with publishing apps that were built using Eclipse, you may be wondering about the android:debuggable attribute in the manifest. Android Studio adds this flag automatically based on the build type. For a release build, this is set to false for us, so we don’t need to do anything. Read more here.
Related Links
Related Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign upRelated Discussions
Have questions about this video? Start a discussion with the community and Treehouse staff.
Sign up
There is a ton of useful information on
the Android developer site about how to
0:01
publish an app.
0:05
Just click on Distribute up here at the
top, and
0:06
then Google Play over here on the left.
0:08
This can be a little overwhelming though,
navigating all this documentation.
0:11
Which is why I'm here.
0:14
Just know that you can find lots of
information about anything not covered in
0:15
these videos.
0:19
And, as always, check out the Treehouse
forum for additional help or discussion.
0:19
Now, there's also a helpful publishing
overview document in
0:24
the Develop section here.
0:26
So lets navigate to Develop > Tools.
0:28
And then on the left we want to select
Workflow and in here, one more time,
0:31
go down to Publishing.
0:36
Now specifically, we want to look at this
section called Preparing for Release.
0:38
Now see [LAUGH] I told you there was a lot
of information in here about publishing.
0:43
Maybe too much.
0:47
Anyhow, I wanna highlight a section down
here that says,
0:49
turn off logging and debugging.
0:53
We want to make sure we disable any calls
to any log methods,
0:56
because they can affect performance of our
app.
0:59
And we don't wanna clutter the log head
either.
1:01
So we need to change a few settings in our
app before we publish it.
1:03
It seems like a pain, but thankfully,
there's an easy way to do this.
1:07
Where we don't have to go in and remove
every single call to a log method.
1:09
Now you're wondering yes, we can publish
an app without doing this step, but
1:13
it's recommended that we do it for those
performance reasons.
1:17
It's also a nice safety for us as
developers in case we accidentally left in
1:19
a bunch of verbose logging that would
really impact how the app runs.
1:23
In the fun facts app, we only have one log
statement, so
1:27
it would be easy to either comment it out
or remove it, it's not important.
1:30
But often on bigger applications, we might
have hundreds of log statements or more.
1:33
And we don't want to change all that code
every time we publish and
1:37
update to the app.
1:40
Now fortunately, there's a very easy way
to do this automatically with our
1:41
tools and Android studio.
1:44
Android developer tools include something
called,
1:46
ProGuard, that can be configured to affect
our final APK in different ways.
1:47
There's a lot we can do with the ProGuard
tool.
1:52
But for now, all we are concerned about is
adding some statements to
1:54
strip calls to any of the log methods.
1:57
To do this, we need to change two files.
2:00
First, open up the build.gradle file, here
in the app modules.
2:02
So, here, under App.
2:06
It's, you can find it under the source
directory and
2:08
then double click on build.gradle.
2:11
In here notice the build type section and
inside is a section for release builds.
2:13
Which is again, what we're about to build.
2:17
By default, ProGuard is turned off with
this run Proguard line which is
2:20
set to false.
2:23
So, let's enable it by changing false to
true.
2:24
The next line here gets some standard
default Proguard settings from
2:28
the file listed right here, get default
Proguard file, pro-guardandroid.txt.
2:31
The second file listed over here is where
we can add some custom commands.
2:36
But wait, we actually need to switch to a
different standard file.
2:39
This may be a a little confusing, but
2:43
hopefully it makes sense here at the end
when we get it working.
2:45
So here where it says proguard-android,
before the .txt add -optimize.
2:48
This uses a different default ProGuard
file that is better suited for
2:54
optimizing our APK file.
2:58
Okay, now let's sync these gradle changes
using this sync gradle button up here.
3:00
Anytime we make a change to gradle
settings in here,
3:05
we need to sync the changes.
3:07
Okay, now it's working down here.
3:08
And okay, it finished without any errors.
3:10
Cool.
So now we
3:13
can edit the proguard-rules file listed
over here.
3:14
This is located in our project directory
as well.
3:17
Once again, it's in the app module,
3:19
and it's right here below our build.gradle
file.
3:20
So let's double click on this.
3:23
Now, when we open this we see everything
is commented out with the hash tags here
3:24
at the beginning of the lines.
3:28
I'm going to paste in some lines that are
available in the teacher's notes below for
3:30
you to copy and paste as well.
3:33
So, this is an option for Proguard called
assumenosideeffects.
3:36
This is only applicable when optimizing.
3:40
Which is why we had to switch to that
other default file.
3:42
But the basic idea is that these methods
listed here from the log class,
3:44
named up here, will be removed by
proguard.
3:49
Okay, let's save the changes to this file,
and
3:53
now we're ready to build our release ready
APK.
3:55
I should note though,
3:58
that if you are logging sensitive
information, like sensitive user details.
3:59
You will need to use a different method to
remove the strings that
4:03
are actually logged in the log methods.
4:06
APK files can be de compiled and people
can actually look at your code.
4:09
So you need to remember this if you're
ever coding sensitive information.
4:12
The actual calls to these log methods are
stripped, but
4:16
the code is still in here and it would be
visible when decompiled.
4:19
You need to sign up for Treehouse in order to download course files.
Sign upYou need to sign up for Treehouse in order to set up Workspace
Sign up