Android Studio Gradle programming

Question

Okay, I've watched the YouTube video with Xavier Ducrohet on the new Android build system. I've even switched to using Android Studio and am happy with it. Now I need to customize the build rules to do things the way I want, and one of which is automatically setting the codeVersion and codeName in the manifest file.

Xavier show the start of how to do this in one of his slides:

def getVersionCode() {
    def code = ...
    return code
}

android {
    defaultConfig {
        versionCode getVersionCode()
    }
}

So could some one be so kind as to point me to good resource for filling in the dots?

To be more specific I want to run a script like git describe --dirty | sed -e 's/^v//' to determine the versionName and git tag | grep -c ^v to get the versionCode.

Thanks

Update

I've tried the following gradle.build script without success. It builds just fine but the version name in the App Info page of my installed apps doesn't change.

task getVersionName(type:Exec) {
  commandLine '../scripts/version-name.sh'

  //store the output instead of printing to the console:
  standardOutput = new ByteArrayOutputStream()

  //extension method stopTomcat.output() can be used to obtain the output:
  ext.output = {
    return standardOutput.toString()
  }
}

buildscript {
    repositories {
        maven { url 'http://repo1.maven.org/maven2' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.4'
    }
}
apply plugin: 'android'

dependencies {
    compile project(':Common')
}

android {
    compileSdkVersion 17
    buildToolsVersion "17.0.0"

    defaultConfig {
        minSdkVersion 7
        targetSdkVersion 16

        versionName getVersionName()
    }
}

If I replace the config versionName getVersionName() with versionName 'Some Text' then it works and the build name becomes Some Text in the App Info. So why doesn't my getVersionName function work?

Update 2

Still not working - but almost!

Shell script:

#/bin/bash

NAME=`git describe --dirty | sed -e 's/^v//'`
COMMITS=`echo ${NAME} | sed -e 's/[0-9\.]*//'`

if [ "x${COMMITS}x" = "xx" ] ; then

    VERSION="${NAME}"

else

    BRANCH=" (`git branch | grep "^\*" | sed -e 's/^..//'`)"
    VERSION="${NAME}${BRANCH}"

fi

logger "Build version: ${VERSION}"

echo ${VERSION}

This works, and the log line confirms that the script is called multiple times when making the project. But the versionName is still being blank. I suspect that it is the Gradle side of things that is still not getting stdout.

task getVersionCode(type: Exec) {
    exec { commandLine '../scripts/version-code.sh' }

    //store the output instead of printing to the console:
    standardOutput = new ByteArrayOutputStream()

    ext.output = {
        return standardOutput.toString()
    }
}

task getVersionName(type: Exec) {
    exec { commandLine '../scripts/grMobile/scripts/version-name.sh' }

    //store the output instead of printing to the console:
    standardOutput = new ByteArrayOutputStream()

    ext.output = {
        return standardOutput.toString()
    }
}

buildscript {
    repositories {
        maven { url 'http://repo1.maven.org/maven2' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.4'
    }
}
apply plugin: 'android'

dependencies {
    compile project(':Common')
}

android {
    compileSdkVersion 17
    buildToolsVersion "17.0.0"

    defaultConfig {
        minSdkVersion 7
        targetSdkVersion 16

        versionCode getVersionCode()
        versionName getVersionName.output()
    }
}

Answer 1

After hunting around I finally found a solution for this.

Groovy, the language of the build.gradle file, allows commands to be easily run. Here is the solution:

def buildCode
     = file("../scripts/version-code.sh")
         .toString().execute().text.trim().toInteger()
def buildName
     = file("../scripts/version-name.sh")
          toString().execute().text.trim()

buildscript {
    repositories {
        maven { url 'http://repo1.maven.org/maven2' }
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:0.4'
    }
}
apply plugin: 'android'

dependencies {
    compile files('libs/android-support-v4.jar')
}

android {
    compileSdkVersion 17
    buildToolsVersion "17.0.0"

    defaultConfig {
        minSdkVersion 12
        targetSdkVersion 16

        versionCode buildCode
        versionName buildName
    }
}

file() should be used to reference all file within Gradle.

"<some-command".execute() will run the command, and .text gives you simple access to stdout. I found I needed to run trim() to remove the trailing carriage return. I suppose I could have used echo -n ${VERSION} in my script, but I think the trim() method is better as it allows the script to be run from the command line.

The build script just counts the number of release tags from git. As I tag my releases in the form: 'v' <major-no> '.' <minor-no> [ '.' <bug-fix> ] it just could the tags that start with a lower case 'v' followed by any digit:

#/bin/bash

git tag | grep -c ^v[0-9]

Before you build with this configuration don't forget to create at least one release tag. I tag right at the start of the project in the following way:

$ git tag -m "Start of development" v0.0