Develop Reference

External reference/variable in build.gradle file

Is it possible to use some external reference or variable in build.gradle files?
I have several build.gradle files in my app source files, including the one for module app, module base, module player, etc. (it depends on the structure of your code and the names of your packages).
Inside of each of these files is the following or similar structure:
defaultConfig {
minSdkVersion 23
targetSdkVersion 28
versionCode 1
versionName "1.0.001"
}
Is there any way I can code this the way that I don't have to change these values in every file? Is it possible to use some external reference or variable and that way I can edit my versionCode, versionName, etc. just on one place?

In your Project gradle
ext {
minSdkVersion = 14
targetSdkVersion = 26
compileSdkVersion = 26
buildToolsVersion = '26.0.2'
// App dependencies
supportLibraryVersion = '26.1.0'
mockitoVersion = '1.10.19'
roomVersion = "1.0.0"
}
In your App gradle
android {
compileSdkVersion rootProject.ext.compileSdkVersion
buildToolsVersion rootProject.ext.buildToolsVersion
defaultConfig {
minSdkVersion rootProject.ext.minSdkVersion
targetSdkVersion rootProject.ext.targetSdkVersion
.
.
}
}
dependencies {
// App's dependencies, including test
compile "com.android.support:appcompat-v7:$rootProject.supportLibraryVersion"
}

Go to File/Project structure/app/flavors then you can get versionCode, versionName, etc then change them what you want and it effects all of your Files.
Check this Image

Yes it is.
In your project-level Gradle config (the one in the root of your project, outside any module folders), you can define variables under the buildscript block:
ext.thisVersionCode = 1
ext.thisVersionName = "1.0.001"
Then you should be able to reference them from your module-level configs:
defaultConfig {
versionCode = rootProject.ext.thisVersionCode
versionName = rootProject.ext.thisVersionName
}

You can define variables in top level build.gradle file and then reference these variables in each module's build.gradle - that way youll be changing them only once in one file.
to give you an example,this is top level file https://github.com/Ejstn/android-starter/blob/master/build.gradle
and this one is module level file: https://github.com/Ejstn/android-starter/blob/master/app/build.gradle
You can also declare whole dependency as variable like in this google's app: https://github.com/google/santa-tracker-android/blob/master/build.gradle

Location of espresso test reports into files created dynamically

Currently, all my test reports are being created and stored in the folder 'test-reports' in the project root directory. Below is the gradle file, in which I have specified the directory under 'testOptions'.
android {
compileSdkVersion 26
defaultConfig {
applicationId "com.example.edk1kor.decodedemov3"
minSdkVersion 15
targetSdkVersion 26
versionCode 1
versionName "1.0"
testInstrumentationRunner "android.support.test.runner.AndroidJUnitRunner"
testOptions{
reportDir "$rootDir/test-reports"
}
}
I want to create a new folder, each time a test is run. Is it possible to dynamically create a folder each time? If not via gradle code, via the android source code?

Importing OpenCV Sample to Android Studio

I am trying to import a OpenCV sample I got from http://ee368.stanford.edu/Android/OpenCV/ to Android Studio on a windows machine.
However, I'm getting the following error
* Project CVCamera MSER:C:\AndroidDevelopment\CVCamera_MSER\project.properties:
Library reference ..\..\android-jni could not be found
Path is C:\AndroidDevelopment\CVCamera_MSER\..\..\android-jni which resolves to C:\android-jni
Any ideas?
EDIT - more info:
I'm using the experimental gradle plugin
`classpath 'com.android.tools.build:gradle-experimental:0.6.0-alpha7'
And my gradle file is as follows:
apply plugin: 'com.android.model.application'
model {
android {
compileSdkVersion 23
buildToolsVersion "23.0.2"
defaultConfig.with {
applicationId "co.vispera.moka"
minSdkVersion.apiLevel 17
targetSdkVersion.apiLevel 23
versionCode 1
versionName "1.0"
}
}
android.ndk {
moduleName = "mymodule"
// ldLibs.addAll(['log'])
// cppFlags.add("-std=c++11")
// cppFlags.add("-fexceptions")
// stl = '
}
}

1.Maybe your sample's default API version codes are too low.
If you're using Android Studio, try changing build.grade Version codes to newer ones.
example:
android {
compileSdkVersion 23
buildToolsVersion "23.0.2"
defaultConfig {
minSdkVersion 19
targetSdkVersion 23
}
}
2.If same thing happens, try copying OpenCV libs folder to your project.
Copy OpenCV libs folder,(OpenCVPath/sdk/native/libs)
and paste it inside your app's 'main' folder.
Don't forget to rename it to 'jniLibs'.

Change Asset Path in Android Studio

I'd like to change the path for where my assets live. This is because these assets will change often and are shared with other apps (i.e. iOS app) in another build folder. How can I do this?

To change the asset path you can tell your project to point to a different directory using the sourceSets command in your apps build.gradle file.
Here's how the build.gradle file looks like:
android {
compileSdkVersion 23
buildToolsVersion "23.0.1"
defaultConfig {
minSdkVersion 19
targetSdkVersion 23
versionCode 1
versionName "1.0"
}
sourceSets {
main {
assets.srcDirs = ['../../../build/android-assets']
}
}
...

Android Studio 1.0 and error "Library projects cannot set applicationId"

After updating Android Studio to 1.0, I see this error:
Error: Library projects cannot set applicationId. applicationId is set
to 'com.super.app' in default config.
I updated the Gradle plugin as suggested but I did not understand how to fix this.

Based on this info:
ApplicationId in Library Projects
You cannot use applicationId to customize the package of a library project. The package name has to be fixed in library projects (and specified as packageName in the manifest). The Gradle plugin did not enforce this restriction earlier.
Removing applicationId variable from the library's build.gradle file should resolve the issue.

Thanks to Joel for his correct answer: I need to remove only 1 line from te .gradle file:
defaultConfig {
applicationId "com.super.app" <---- remove this line
minSdkVersion 15
targetSdkVersion 19
versionCode 1
versionName "1.0"
}
becomes
defaultConfig {
minSdkVersion 15
targetSdkVersion 19
versionCode 1
versionName "1.0"
}
and my AndroidManifest.xml
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
package="com.super.app">
...
This is the right solution if you don't need to rename the package name of your app. To rename it you need to use "flavours":
android {
...
productFlavors {
flavor1 {
applicationId 'com.super.superapp'
}
}

Libraries can't set applicationId and if you are working in a multi-module project and picking up flavors from a separate file , none of the above answers will work. For a modularized app, you need the following steps -
Create a flavors.gradle file in project root directory
ext.flavorConfig = { // 1
flavorDimensions "pricing"
productFlavors {
free {
dimension "pricing"
ext.myApplicationIdSuffix = '.free' // 2
}
paid {
dimension "pricing"
ext.myApplicationIdSuffix = '.paid'
}
}
productFlavors.all { flavor -> // 3
if (flavor.hasProperty('myApplicationIdSuffix') && isApplicationProject()) {
flavor.applicationIdSuffix = flavor.myApplicationIdSuffix
}
}
}
def isApplicationProject() { // 4
return project.android.class.simpleName.startsWith('BaseAppModuleExtension')
}
In 1 we export a closure so that we can use it in our modules’ build.gradle files.
In 2 we define a custom myApplicationIdSuffix property. We cannot simply have applicationIdSuffix as it is not possible to use it in library modules (build would fail if you did).
In 3 we iterate over created flavors and set applicationIdSuffix if we detect that it’s an application module only.
4 is a way to check where this closure is being used.
All that’s left is to use this closure in our modules’ build.gradle files. E.g. in application module this would look like this:
apply plugin: 'com.android.application'
apply from: "${rootProject.projectDir}/flavors.gradle"
android {
// other config...
with flavorConfig
}
If this isn't clear, you can check out this article for better understanding.

Just incase it helps some one :
When i imported an eclipse project into android studio,i got an error ::
"Error:Application and test application id cannot be the same"
Strange though,but i looked into the build.gradle and found the two placeholders,one for the application and other for testapplication.
I removed the testApplicationId from that as is suggested in this post and this helped me resolve the issue.
Note: This explaination is not related to the errors posted in this question,but might help someone who is getting a similar error.

You cannot define applicationId for your lib.
But incase you want to use an identifier in your build file, which will give you, your library package name, you can define a variable for the module and then use the value as required.
eg : Library's build.gradle
apply plugin: 'com.android.library'
def libraryGroupId = 'com.google.example'
def libraryArtifactId = project.getName()
def libraryVersion = '1.1'
Also, you can use the value below as needed in your build file itself in lib.
android {
compileSdkVersion 28
defaultConfig {
minSdkVersion 21
targetSdkVersion 28
versionCode 1
versionName "$libraryVersion"
resValue "string", "Library", libraryGroupId"
}
}