Develop Reference

Is it possible to get dependency version at runtime, including from library itself?

Background
Suppose I make an Android library called "MySdk", and I publish it on Jitpack/Maven.
The user of the SDK would use it by adding just the dependency of :
implementation 'com.github.my-sdk:MySdk:1.0.1'
What I'd like to get is the "1.0.1" part from it, whether I do it from within the Android library itself (can be useful to send to the SDK-server which version is used), or from the app that uses it (can be useful to report about specific issues, including via Crashlytics).
The problem
I can't find any reflection or gradle task to reach it.
What I've tried
Searching about it, if I indeed work on the Android library (that is used as a dependency), all I've found is that I can manage the version myself, via code.
Some said I could use BuildConfig of the package name of the library, but then it means that if I forget to update the code a moment before I publish the dependency, it will use the wrong value. Example of using this method:
plugins {
...
}
final def sdkVersion = "1.0.22"
android {
...
buildTypes {
release {
...
buildConfigField "String", "SDK_VERSION", "\"" + sdkVersion + "\""
}
debug {
buildConfigField "String", "SDK_VERSION", "\"" + sdkVersion + "-unreleased\""
}
}
Usage is just checking the value of BuildConfig.SDK_VERSION (after building).
Another possible solution is perhaps from gradle task inside the Android-library, that would be forced to be launched whenever you build the app that uses this library. However, I've failed to find how do it (found something here)
The question
Is it possible to query the dependency version from within the Android library of the dependency (and from the app that uses it, of course), so that I could use it during runtime?
Something automatic, that won't require me to update it before publishing ?
Maybe using Gradle task that is defined in the library, and forced to be used when building the app that uses the library?

You can use a Gradle task to capture the version of the library as presented in the build.gradle dependencies and store the version information in BuildConfig.java for each build type.
The task below captures the version of the "appcompat" dependency as an example.
dependencies {
implementation 'androidx.appcompat:appcompat:1.4.0'
}
task CaptureLibraryVersion {
def libDef = project.configurations.getByName('implementation').allDependencies.matching {
it.group.equals("androidx.appcompat") && it.name.equals("appcompat")
}
if (libDef.size() > 0) {
android.buildTypes.each {
it.buildConfigField 'String', 'LIB_VERSION', "\"${libDef[0].version}\""
}
}
}
For my example, the "appcompat" version was 1.4.0. After the task is run, BuildConfig.java contains
// Field from build type: debug
public static final String LIB_VERSION = "1.4.0";
You can reference this field in code with BuildConfig.LIB_VERSION. The task can be automatically run during each build cycle.

The simple answer to your question is 'yes' - you can do it. But if you want a simple solution to do it so the answer transforms to 'no' - there is no simple solution.
The libraries are in the classpath of your package, thus the only way to access their info at the runtime would be to record needed information during the compilation time and expose it to your application at the runtime.
There are two major 'correct' ways and you kinda have described them in your question but I will elaborate a bit.
The most correct way and relatively easy way is to expose all those variables as BuildConfig or String res values via gradle pretty much as described here. You can try to generify the approach for this using local-prefs(or helper gradle file) to store versions and use them everywhere it is needed. More info here, here, and here
The second correct, but much more complicated way is to write a gradle plugin or at least some set of tasks for collecting needed values during compile-time and providing an interface(usually via your app assets or res) for your app to access them during runtime. A pretty similar thing is already implemented for google libraries in Google Play services Plugins so it would be a good place to start.
All the other possible implementations are variations of the described two or their combination.

You can create buildSrc folder and manage dependencies in there.
after that, you can import & use Versions class in anywhere of your app.

Difference between using tensorflow-lite:0.0.0-nightly and tensorflow-lite in an Android App

I am trying to debug an existing Android app that uses tensorflow-lite to detect objects. The app implements the tensorflow library like below :
implementation('org.tensorflow:tensorflow-lite:0.0.0-nightly') { changing = true }
implementation('org.tensorflow:tensorflow-lite-gpu:0.0.0-nightly') { changing = true }
implementation('org.tensorflow:tensorflow-lite-support:0.0.0-nightly') { changing = true }
But examples I have found online for object detection, have implemented tensorflow-lite in the following way :
implementation 'org.tensorflow:tensorflow-lite-task-vision:0.2.0'
My questions are:
What is the difference between using the nightly snapshot and the "normal" library. From what I can gather online, the nightly build is an experimental branch and may contain bugs? I'm just confused about this because the existing app does not contain a reference to sonatype maven repository, which I understand was required to get the nightly builds to work in the app.
allprojects {
mavenCentral
maven {
name 'ossrh-snapshot'
url 'http://oss.sonatype.org/content/repositories/snapshots'
}
}
My second question is what does this do line do : { changing = true } ?
PS: We are using our own custom trained model/tflite.

Changing, or snapshot versions are used when you need Gradle to get a new version of the dependency with the same name from time to time (once in 24 hours, unless specified explicitly otherwise).
I believe that whoever chose the nightly version of tensorflow, was wrong. As you say, this version may have bugs, and worse, these bugs will change overnight. Find some fixed version that you are comfortable with, study its changelog, and reset your implementation to refer to this version.

Implementing Huawei Mobile Services

I've been reading the huawei's documentation to implement their services.
The documentation is easy and clear, but I have a few doubts.
Huawei's SDK can exist in the same apk for both stores? or I need implement a different apk for gms and hms?
If I implement hms how can I know if hms is reading data from other devices like MOTO etc.

You can use both of HMS and GMS services.
Some of HMS service support to non-Huawei devices (like Scan Kit) and some of kit tighlty bound the EMUI and Huawei phones.
If you need to apply you already created applıcation moved into HMS ecosystem, you can use HMS Toolkit and quickly implemented HMS services. (details)

Huawei's SDK can exist in the same apk for both stores?
- yes, you can create one app and implement libraries for GMS and HMS.
If I implement hms how can I know if hms is reading data from other devices like MOTO etc.
You call functions from Google's or Huawei's responsible for detecting services.
Please check out my latest answer from here: https://stackoverflow.com/a/60587678/619673

There are a couple ways to handle this. Of course you can choose to maintain 2 sets of source code, which is highly not recommended, and you can choose to keep libraries from both sides, detect which service is available and call them accordingly. I would however recommend implementating different product flavours and build your product according to the platform.
android{
flavorDimensions "default"
productFlavors{
hmsVersion{
//select the dimension of flavor
dimension "default"
//Configure this flavor specific app name published in Huawei App Gallery
resValue "string", "flavored_app_name", "App name"
}
gmsVersion{
//select the dimension of flavor
dimension "default"
//Configure this flavor specific app name published in Play Store
resValue "string", "flavored_app_name", "App Name"
}
}
}
and then you can do something like this
// HMS Flavor
hmsVersionImplementation 'com.huawei.hms:hianalytics:4.0.3.300'
// GMS Flavor
gmsVersionImplementation 'com.google.firebase:firebase-analytics:17.4.0'

'ProductFlavor.resConfigs' has a value 'auto' which is obsolete and has not been replaced

How to fix the warning below? Are there any alternatives to 'auto'?
Warning:DSL element 'ProductFlavor.resConfigs' has a value 'auto' which is obsolete and has not been replaced. It will be removed at the end of 2018
android {
...
flavorDimensions "device", "paid", "market"
productFlavors {
phone {
// Phone config version for the application
resConfigs ("auto")
dimension "device"
matchingFallbacks = ['mobile']
}
...
}
...
}

This is the error after updating to Android Studio 3.1:
Based on the official advise here the best thing to do is removing the tag entirely if you support all the languages or supply an array with the language's code your app supports like:
resConfigs "en", "de", "it", "fr" // etc. etc.
More info:
This is one of the resources optimization proposed by the official documentation here so i decided to test this flag with those FirebaseUI dependencies in a sample project
implementation "com.firebaseui:firebase-ui-auth:$firebase_ui_version"
implementation "com.firebaseui:firebase-ui-database:$firebase_ui_version"
implementation "com.firebaseui:firebase-ui-storage:$firebase_ui_version"
creating the debug APK with both the options and those are the results:
Using resConfigs "auto" the debug APK was: 3,793 KB
Using resConfigs "en" (so 1 language only) the debug APK was: 3,294 KB
This means that with all the string resources for all the languages of those dependencies I got only ~500KB of size increase. That's something you could reason about, you definitely should make a test with the dependencies you use and see if the size increase is negligible or not and consequently decide to provide the list of supported languages or remove the resConfigs option.
PS: If you are using Android FirebaseUI this was one of the suggested optimizations, I've created an issue here about the thing and this has been solved immediately by the awesome guy called SUPERCILEX

auto is no longer supported because it created a number of issues with multi-module projects. Instead, you should specify the locale that your app supports. Android plugin 3.1.0 and higher ignore the auto argument, and Gradle packages all string resources your app and its dependencies provide.
com.android.tools.build:gradle:3.2.0-alpha08 BaseFlavor.java
* <p><b>Note:</b> <code>auto</code> is no longer supported because it created a number of
* issues with multi-module projects. Instead, you should specify the locale that your app
* supports, as shown in the sample above. Android plugin 3.1.0 and higher ignore the <code>auto
* </code> argument, and Gradle packages all string resources your app and its dependencies
* provide.

How to shrink code - 65k method limit in dex

I have a rather large Android app that relies on many library projects. The Android compiler has a limitation of 65536 methods per .dex file and I am surpassing that number.
There are basically two paths you can choose (at least that I know of) when you hit the method limit.
1) Shrink your code
2) Build multiple dex files (see this blog post)
I looked into both and tried to find out what was causing my method count to go so high. The Google Drive API takes the biggest chunk with the Guava dependency at over 12,000. Total libs for Drive API v2 reach over 23,000!
My question I guess is, what do you think I should do? Should I remove Google Drive integration as a feature of my app? Is there a way to shrink the API down (yes, I use proguard)? Should I go the multiple dex route (which looks rather painful, especially dealing with third party APIs)?

It looks like Google has finally implementing a workaround/fix for surpassing the 65K method limit of dex files.
About the 65K Reference Limit
Android application (APK) files contain
executable bytecode files in the form of Dalvik Executable (DEX)
files, which contain the compiled code used to run your app. The
Dalvik Executable specification limits the total number of methods
that can be referenced within a single DEX file to 65,536, including
Android framework methods, library methods, and methods in your own
code. Getting past this limit requires that you configure your app
build process to generate more than one DEX file, known as a multidex
configuration.
Multidex support prior to Android 5.0
Versions of the platform prior to Android 5.0 use the Dalvik runtime
for executing app code. By default, Dalvik limits apps to a single
classes.dex bytecode file per APK. In order to get around this
limitation, you can use the multidex support library, which becomes
part of the primary DEX file of your app and then manages access to
the additional DEX files and the code they contain.
Multidex support for Android 5.0 and higher
Android 5.0 and higher uses a runtime called ART which natively
supports loading multiple dex files from application APK files. ART
performs pre-compilation at application install time which scans for
classes(..N).dex files and compiles them into a single .oat file for
execution by the Android device. For more information on the Android
5.0 runtime, see Introducing ART.
See: Building Apps with Over 65K Methods
Multidex Support Library
This library provides support for building
apps with multiple Dalvik Executable (DEX) files. Apps that reference
more than 65536 methods are required to use multidex configurations.
For more information about using multidex, see Building Apps with Over
65K Methods.
This library is located in the /extras/android/support/multidex/
directory after you download the Android Support Libraries. The
library does not contain user interface resources. To include it in
your application project, follow the instructions for Adding libraries
without resources.
The Gradle build script dependency identifier for this library is as
follows:
com.android.support:multidex:1.0.+ This dependency notation specifies
the release version 1.0.0 or higher.
You should still avoid hitting the 65K method limit by actively using proguard and reviewing your dependencies.

you can use the multidex support library for that, To enable multidex
1) include it in dependencies:
dependencies {
...
compile 'com.android.support:multidex:1.0.0'
}
2) Enable it in your app:
defaultConfig {
...
minSdkVersion 14
targetSdkVersion 21
....
multiDexEnabled true
}
3) if you have a application class for your app then Override the attachBaseContext method like this:
package ....;
...
import android.support.multidex.MultiDex;
public class MyApplication extends Application {
....
#Override
protected void attachBaseContext(Context context) {
super.attachBaseContext(context);
MultiDex.install(this);
}
}
4) if you don't have a application class for your application then register android.support.multidex.MultiDexApplication as your application in your manifest file. like this:
<application
...
android:name="android.support.multidex.MultiDexApplication">
...
</application>
and it should work fine!

Play Services 6.5+ helps:
http://android-developers.blogspot.com/2014/12/google-play-services-and-dex-method.html
"Starting with version 6.5, of Google Play services, you’ll be able to
pick from a number of individual APIs, and you can see"
...
"this will transitively include the ‘base’ libraries, which are used
across all APIs."
This is good news, for a simple game for example you probably only need the base, games and maybe drive.
"The complete list of API names is below. More details can be found on
the Android Developer site.:
com.google.android.gms:play-services-base:6.5.87
com.google.android.gms:play-services-ads:6.5.87
com.google.android.gms:play-services-appindexing:6.5.87
com.google.android.gms:play-services-maps:6.5.87
com.google.android.gms:play-services-location:6.5.87
com.google.android.gms:play-services-fitness:6.5.87
com.google.android.gms:play-services-panorama:6.5.87
com.google.android.gms:play-services-drive:6.5.87
com.google.android.gms:play-services-games:6.5.87
com.google.android.gms:play-services-wallet:6.5.87
com.google.android.gms:play-services-identity:6.5.87
com.google.android.gms:play-services-cast:6.5.87
com.google.android.gms:play-services-plus:6.5.87
com.google.android.gms:play-services-appstate:6.5.87
com.google.android.gms:play-services-wearable:6.5.87
com.google.android.gms:play-services-all-wear:6.5.87

In versions of Google Play services prior to 6.5, you had to compile the entire package of APIs into your app. In some cases, doing so made it more difficult to keep the number of methods in your app (including framework APIs, library methods, and your own code) under the 65,536 limit.
From version 6.5, you can instead selectively compile Google Play service APIs into your app. For example, to include only the Google Fit and Android Wear APIs, replace the following line in your build.gradle file:
compile 'com.google.android.gms:play-services:6.5.87'
with these lines:
compile 'com.google.android.gms:play-services-fitness:6.5.87'
compile 'com.google.android.gms:play-services-wearable:6.5.87'
for more reference, you can click here

Use proguard to lighten your apk as methods that are unused will not be in your final build. Double check you have following in your proguard config file to use proguard with guava (my apologies if you already have this, it wasn't known at time of writing) :
# Guava exclusions (http://code.google.com/p/guava-libraries/wiki/UsingProGuardWithGuava)
-dontwarn sun.misc.Unsafe
-dontwarn com.google.common.collect.MinMaxPriorityQueue
-keepclasseswithmembers public class * {
public static void main(java.lang.String[]);
}
# Guava depends on the annotation and inject packages for its annotations, keep them both
-keep public class javax.annotation.**
-keep public class javax.inject.**
In addition, if you are using ActionbarSherlock, switching to the v7 appcompat support library will also reduce your method count by a lot (based on personal experience). Instructions are located :
http://developer.android.com/tools/support-library/features.html#v7-appcompat Actionbar
http://developer.android.com/tools/support-library/setup.html#libs-with-res

You could use Jar Jar Links to shrink huge external libraries like Google Play Services (16K methods!)
In your case you will just rip everything from Google Play Services jar except common internal and drive sub-packages.

For Eclipse users not using Gradle, there are tools that will break down the Google Play Services jar and rebuild it with only the parts you want.
I use strip_play_services.sh by dextorer.
It can be difficult to know exactly which services to include because there are some internal dependencies but you can start small and add to the configuration if it turns out that needed things are missing.

I think that in the long run breaking your app in multiple dex would be the best way.

Multi-dex support is going to be the official solution for this issue. See my answer here for the details.

If not to use multidex which making build process very slow.
You can do the following.
As yahska mentioned use specific google play service library.
For most cases only this is needed.
compile 'com.google.android.gms:play-services-base:6.5.+'
Here is all available packages Selectively compiling APIs into your executable
If this will be not enough you can use gradle script. Put this code in file 'strip_play_services.gradle'
def toCamelCase(String string) {
String result = ""
string.findAll("[^\\W]+") { String word ->
result += word.capitalize()
}
return result
}
afterEvaluate { project ->
Configuration runtimeConfiguration = project.configurations.getByName('compile')
println runtimeConfiguration
ResolutionResult resolution = runtimeConfiguration.incoming.resolutionResult
// Forces resolve of configuration
ModuleVersionIdentifier module = resolution.getAllComponents().find {
it.moduleVersion.name.equals("play-services")
}.moduleVersion
def playServicesLibName = toCamelCase("${module.group} ${module.name} ${module.version}")
String prepareTaskName = "prepare${playServicesLibName}Library"
File playServiceRootFolder = project.tasks.find { it.name.equals(prepareTaskName) }.explodedDir
def tmpDir = new File(project.buildDir, 'intermediates/tmp')
tmpDir.mkdirs()
def libFile = new File(tmpDir, "${playServicesLibName}.marker")
def strippedClassFileName = "${playServicesLibName}.jar"
def classesStrippedJar = new File(tmpDir, strippedClassFileName)
def packageToExclude = ["com/google/ads/**",
"com/google/android/gms/actions/**",
"com/google/android/gms/ads/**",
// "com/google/android/gms/analytics/**",
"com/google/android/gms/appindexing/**",
"com/google/android/gms/appstate/**",
"com/google/android/gms/auth/**",
"com/google/android/gms/cast/**",
"com/google/android/gms/drive/**",
"com/google/android/gms/fitness/**",
"com/google/android/gms/games/**",
"com/google/android/gms/gcm/**",
"com/google/android/gms/identity/**",
"com/google/android/gms/location/**",
"com/google/android/gms/maps/**",
"com/google/android/gms/panorama/**",
"com/google/android/gms/plus/**",
"com/google/android/gms/security/**",
"com/google/android/gms/tagmanager/**",
"com/google/android/gms/wallet/**",
"com/google/android/gms/wearable/**"]
Task stripPlayServices = project.tasks.create(name: 'stripPlayServices', group: "Strip") {
inputs.files new File(playServiceRootFolder, "classes.jar")
outputs.dir playServiceRootFolder
description 'Strip useless packages from Google Play Services library to avoid reaching dex limit'
doLast {
def packageExcludesAsString = packageToExclude.join(",")
if (libFile.exists()
&& libFile.text == packageExcludesAsString
&& classesStrippedJar.exists()) {
println "Play services already stripped"
copy {
from(file(classesStrippedJar))
into(file(playServiceRootFolder))
rename { fileName ->
fileName = "classes.jar"
}
}
} else {
copy {
from(file(new File(playServiceRootFolder, "classes.jar")))
into(file(playServiceRootFolder))
rename { fileName ->
fileName = "classes_orig.jar"
}
}
tasks.create(name: "stripPlayServices" + module.version, type: Jar) {
destinationDir = playServiceRootFolder
archiveName = "classes.jar"
from(zipTree(new File(playServiceRootFolder, "classes_orig.jar"))) {
exclude packageToExclude
}
}.execute()
delete file(new File(playServiceRootFolder, "classes_orig.jar"))
copy {
from(file(new File(playServiceRootFolder, "classes.jar")))
into(file(tmpDir))
rename { fileName ->
fileName = strippedClassFileName
}
}
libFile.text = packageExcludesAsString
}
}
}
project.tasks.findAll {
it.name.startsWith('prepare') && it.name.endsWith('Dependencies')
}.each { Task task ->
task.dependsOn stripPlayServices
}
project.tasks.findAll { it.name.contains(prepareTaskName) }.each { Task task ->
stripPlayServices.mustRunAfter task
}
}
Then apply this script in your build.gradle, like this
apply plugin: 'com.android.application'
apply from: 'strip_play_services.gradle'

If using Google Play Services, you may know that it adds 20k+ methods. As already mentioned, Android Studio has the option for modular inclusion of specific services, but users stuck with Eclipse have to take modularisation into their own hands :(
Fortunately there's a shell script that makes the job fairly easy. Just extract to the google play services jar directory, edit the supplied .conf file as needed and execute the shell script.
An example of its use is here.

If using Google Play Services, you may know that it adds 20k+ methods. As already mentioned, Android Studio has the option for modular inclusion of specific services, but users stuck with Eclipse have to take modularisation into their own hands :(
Fortunately there's a shell script that makes the job fairly easy. Just extract to the google play services jar directory, edit the supplied .conf file as needed and execute the shell script.
An example of its use is here.
Just like he said, I replaces compile 'com.google.android.gms:play-services:9.0.0' just with the libraries that I needed and it worked.