I have an existing gradle-based Android application, and I would like to use it as a library module in another app while still being able to build it a standalone app (and keep the same package name).
I've tried to convert it into a library module and create a new app that wraps it, but the app cannot have the same package name as one of its lib modules.
Changing the package name of the standalone app is not an option because it's alreayd published on the Play Store. And changing the package name of the library module would have huge impacts (e.g in the java code).
How could I achieve that?
Is there any other altenative, such as having two build.gradle files in the project (one for app module definition, and one for the library module)?
Related
I want to make a separate module so I can share it between projects. The module is going to have android components. So upon creating a new module the options are Phone & Tablet module and Android Library. I wanted to know what's the difference between the two. thanks
What is Module? From the Add a Module for a New Device documentation:
Modules provide a container for your app's source code, resource
files, and app level settings, such as the module-level build file and
Android manifest file. Each module can be independently built, tested,
and debugged.
What is Android Library? From Create an Android Library documentation:
An Android library is structurally the same as an Android app module.
It can include everything needed to build an app, including source
code, resource files, and an Android manifest. However, instead of
compiling into an APK that runs on a device, an Android library
compiles into an Android Archive (AAR) file that you can use as a
dependency for an Android app module. Unlike JAR files, AAR files can
contain Android resources and a manifest file, which allows you to
bundle in shared resources like layouts and drawables in addition to
Java classes and methods.
You can't access the components from one module to another module.
So, if you need to share components between projects, you need to create Android library. But please remember, you can't run the library. You only can access and use it from the module. Furthermore, you can use Gradle Android Maven plugin to install your library locally.
Check the official doc
Resume:
Modules provide a container for your app's source code, resource files, and app level settings, such as the module-level build file and Android manifest file. Each module can be independently built, tested, and debugged.
Android Studio uses modules to make it easy to add new devices to your project. By following a few simple steps in Android Studio, you can create a module to contain code that's specific to a device type, such as Android Wear or Android TV. Android Studio automatically creates module directories, such as source and resource directories, and a default build.gradle file appropriate for the device type. Also, Android Studio creates device modules with recommended build configurations, such as using the Leanback library for Android TV modules.
In Android Studio 3 there are at least two new module types. First is Instant app module and the second one is feature module. With Instant App module it's quite obvious but feature module from my perspective is the same as the library module. So what is the real difference between library and feature modules and when I should use library module and when feature module?
I would complete Marcin Orlowski scheme like this.
You could picture library module in the same way as dependencies of a given feature or base module.
Hence the library modules will not be packaged in Instant APP APK.
A feature module is a module that applies com.android.feature plugin.
This module type has a dual nature:
When consumed by an application (com.android.application) during build, it produces an aar and works just like a library
When consumed by an Instant App APK (com.android.instantapp), it generates an Instant App APK
Developers should write feature modules just like library modules. The tools provided are responsible for applying the correct nature when used during a build.
In the simplest case an Instant app can have a single feature module.
If there is more than one feature module, these feature-to-feature
dependencies can be defined through the api configuration. In any
case, there must only be a single base feature which is marked with a
baseFeature attribute.
Main source: https://codelabs.developers.google.com/codelabs/android-instant-apps/#3
This all for Instant Apps so you only need it if you are making your app supporting instant app feature
See https://developer.android.com/topic/instant-apps/getting-started/structure.html#basic-app
Android SDK is the core features and software tools that allow you to create an app for the Android Platform. An SDK contains lots of libraries and tools which you will use to develop your application.
A Library is a collection of pre-built compiled code which you can use to extend your application's features. For example, you may need to show some graphics in your application. Instead of creating this from scratch, you may choose to use a pre-built library someone else has developed which will give you the features you need thus saving you some time.
A module is a small part of the application which can be tested and debugged on its own without needing the whole application. This is same for any programming language. Suppose you are building an app with Login feature. To test if the login feature works, you don't need the whole app. Thus the Login part is a module of your application.
The app module builds an app. A library module builds a library.
An app is what a user uses. The output of an app module is an APK, the package of an Android application.
A library is a collection of code that represents something that you want to use in multiple applications or otherwise want to keep in a separate "container" than the rest of the app code. The output of a library module is an AAR And Jar.
Use Feature for linked feature of your instant app (to launch it with deeplink).
Use Library for code dependency in your app or in your Feature modules.
I am currently using a gradle script to compile and generate a .jar library, that is eventually targeted for an android application. I have different customers that would like a specific package name, so I can't give them the library with the package name I am using.
Is there a way a can make this configurable using gradle (preferably)? I basically want to have a way I can specify the package name while (or prior to) building, resulting in a library using the new package name.
I looked online but all I could find was ways I could change package name for an app using gradle or ant. But my project is a library project.
I have a library module in my Android Studio project. Because I would like to publish a free version and a paid version of my app, I've added two application modules that depends on this library project.
If I would like to toast e.g. "FREE" for the free application module and "PAID" for the paid application module, how do I tell the difference of which application module that is active at run-time?
I've had a look at this question but I believe that it contradicts the reason for implementing the library module in the first place.
Initially I thought that I would add two different MainActivity.java in each of the application modules, each with a different Toast message. This did not work, since the library modules MainActivity.java was still shown.
So my questions are; Am I on the right path here, is this how you utilize library modules in Android Studio? If so, how do I add code that is specific to the application module, thus not implemented in the library module, "overriding the default" library module code?
Rather than going with libraries you may want to investigate application flavours under the gradle documentation:
http://tools.android.com/tech-docs/new-build-system/user-guide#TOC-BuildType-and-Product-Flavor-property-reference
My desired end result is to have a Project that can output different productflavors of Mobile, Tv, and Wear apps, that share the same code-base. So I would like the codebase to be a dependency for all three app-types, where each app module would only contain activities and interaction with the codebase.
My first idea was to add a "Android Library Module" to my newly created project, but I noticed that this is really just a new app module with its own resources and everything. I would like the codebase to function more like a "Java Library", but it needs access to packages like "android.graphics.Color".
So in short, is the correct way of achieving this result to use a java library that has a reference to an android sdk or am i just going about this the wrong way?
Continuation of this question at:Does an Android Library need a manifest ,app_name,Icon?
There's no in-between. If you want access to Android APIs, then the library needs to be an Android library so that the build system can properly link it in to dependent projects. It's true that Android Libraries have resources and other things you may not need, but you can ignore those bits and treat it essentially as a plain Java library if you wish. Even if you're not using resources, you may find useful the ability to specify AndroidManifest.xml attributes to be merged into the dependent app.
The Android Library project doesn't build a fully-fledged APK as its output; it generates an AAR, which is conceptually similar to a JAR archive, but has resources and meta-information useful to Android projects.
Supplemental answer defining terms
The Android Studio documentation defines a module as follows:
A module is a collection of source files and build settings that allow
you to divide your project into discrete units of functionality. Your
project can have one or many modules and one module may use another
module as a dependency. Each module can be independently built,
tested, and debugged.
So basically a module is a subproject in your bigger project.
Types of modules
Android app module - The app module is usually what you are working with in a normal project. When you compile it you get an APK file that will run on a device. Here are the different types of app modules that exist:
Phone & Tablet Module
Android Wear Module
Android TV Module
Glass Module
Library module - The purpose of a library is to share code. For example, you could have a project with a couple different app modules. The common code that they both use could be located in the library.
Android Library - In addition to Java code, this allows you to also include Android resource files and a manifest. If you are making an Android project and are wondering what kind of library to use, then choose the Android Library. When compiled it creates an AAR (Android Archive) file.
Java Library - This only allows you to include Java code files, no Android resource files. This is useful for cross-platform code sharing. When compiled it creates a JAR (Java Archive) file.
Google Cloud module - This type of module is the Google Cloud backend for communication with your client side app.
One additional point that I've not seen well documented: An android library module can have a dependency on another android library module or java library module, but a java library module cannot have a dependency on an android library module.