Paperwork

Generate build info for your Android project without breaking incremental compilation

The problem

A common use case is that you want to include the git hash of the last commit and build time into your project, so that you can use their values in your crash reporting tool (for example).

The easiest way to do this is to generate them into your BuildConfig by adding these to your build.gradle

def gitSha = 'git rev-parse --short HEAD'.execute([], project.rootDir).text.trim()
def buildTime = new Date().format("yyyy-MM-dd'T'HH:mm:ss'Z'", TimeZone.getTimeZone("UTC"))

android {
    defaultConfig {
        buildConfigField "String", "GIT_SHA", "\"${gitSha}\""
        buildConfigField "String", "BUILD_TIME", "\"${buildTime}\""
    }
}

But this will break incremental builds, resulting in increased build times all the time.

What this lib offers

Paperwork can generate this information (and more) for you, and put it into a paperwork.json file inside your assets folder instead of using BuildConfig, and helps you read it from there:

Paperwork paperwork = new Paperwork(context);
String gitSha = paperwork.get("gitSha");
String buildTime = paperwork.get("buildTime");

Not just git hash, not just build time: you define what gets generated, and you can use anything that otherwise would break incremental builds.

Many helpers are available for the most common scenarios. See the configuration below.

Build time comparison

Measured three consecutive builds per type, running gradle daemon, hitting "Run 'app'" in Android Studio without touching anything else. Generated info: git hash and build time (using seconds) so that it has a new value every time.

• Without generating build info: 3.989s, 3.915s, 3.902s
• Using BuildConfig fields: 14.843s, 13.844s, 13.194s
• Using Paperwork: 4.356s, 4.075s, 4.042s

Download and setup

Add these dependencies to your build.gradle:

buildscript {
    repositories {
        mavenCentral()
    }

    dependencies {
        classpath 'hu.supercluster:paperwork-plugin:1.2.7'
    }
}

apply plugin: 'hu.supercluster.paperwork'

paperwork {
    // Configuration comes here, see next section for details
}

dependencies {
    compile 'hu.supercluster:paperwork:1.2.7'
}

Lastly, don't forget to add paperwork.json to your .gitignore file.

Configuration

Paperwork doesn't generate anything by default, you have to define whatever data you need in simple key-value pairings. For a list of helper methods you can use, see next section.

paperwork {
    set = [
        someKey1: "someValue",
        someKey2: someHelperMethod()
    ]
}

All the data will be available at runtime by querying for your own defined keys:

Paperwork paperwork = new Paperwork(context);
String data1 = paperwork.get("someKey1");        // will return "someValue"
String data1 = paperwork.get("someKey2");        // will return the result of someHelperMethod()

You can also change the default filename or generate the file somewhere else:

paperwork {
    filename = 'src/main/assets/paperwork.json'
}

Note however, that in order for it to be available in Paperwork runtime, it has to be in the assets folder, and if the filename is not paperwork.json, you have to inject its name in the constructor:

Paperwork paperwork = new Paperwork(context, "paperwork.json");

Helpers

buildTime()

Simple unix timestamp (ms)

buildTime("yyyy-MM-dd HH:mm:ss")

Formatted date string

buildTime("yyyy-MM-dd HH:mm:ss", "GMT")

Formatted date string for a given timezone

gitSha()

The current git SHA

gitTag()

The last git tag (lightweight tags included)

gitInfo()

Runs git describe --tags --always --dirty. Returns a result like "v2.1.0-71-gb88c59a-dirty" (The last tag + how many commits ahead of that tag are we now in the working tree + current hash + whether the working tree has uncommited changes)

gitBranch()

The current git branch

shell("scripts/test.sh")

Runs a shell command and returns its output (doesn't have to be a script)

env("SOME_ENV")

Returns the value of an environment variable

Contributing

Contributions are welcome! Got a question, found a bug, have a new helper method idea? Submit an issue and discuss it!

I'd love to hear about your use case too, especially if it's not covered perfectly.

License

Copyright 2015 Zsolt Kocsi

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

   http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.