SBT and Multimodule project in Intellij - scala

I come from Eclipse and I don't undertand how I can organize my projects in Intellj.
I have read the documentation and understand than project is similar to workspace and module to eclipse project.
I want to create a SBT project with many modules, but there's just one SBT and the dependencies of my modules are different so I want that my ModuleA only has its dependencias and ModuleB the same.
What's the way to manage these kind of things with IntellJ?
I have read http://www.scala-sbt.org/0.12.1/docs/Getting-Started/Multi-Project.html this page, but I don't know if IntellJ manages these things.

Related

With the gradle plugin in Eclipse, how can I get project dependencies like maven?

I'm looking into migrating some of our ancient maven projects over to gradle (so shiny). Things are looking pretty good however I'm unable to get Eclipse/Gradle to adjust the project dependencies appropriately when I have 2 projects checked out. I'm hoping to use a repo for standard jar dependencies but be able to depend directly on a project if it is checked out.
Let's say ProjectB depends on ProjectA. As far as I understand the Eclipse/Maven plugin, it is able to a:
Interrogate the maven dependency for ProjectA and understand its group/artifact/version tuple.
Look through ProjectA eclipse project (if imported) to see if has the same group/artifact/version.
Replace the jar dependency with a project dependency.
This is a powerful feature because it means that a developer does not need to import ProjectA when they are working on ProjectB -- they just get it from the repo. But if they do have it imported, they can make a refactor to ProjectA in Eclipse and it will automagically refactor the dependent code in ProjectB.
How can I get eclipse/gradle to adjust the build-path so that there is a project dependency when available otherwise use the jar?
Things I've looked into:
Gradle "multi-projects" but our code isn't in a hierarchy like that.
Gradle includeFlat but this isn't some simple single directory structure.
resolutionStrategy.dependencySubstitution but I couldn't seem to get it to work. I doubt that findProject(...) is able to find a project that is loaded into Eclipse to it can link the 2 projects together in the classpath.
composite builds seem to use some of the language I'm looking for but it is about importing a build into another build.
Anyone else figured this out? Thanks much in advance.

Adding library dependency in play 2.3.8

I'm trying to add the apache commons email library to my Play project and I'm having trouble.
Firstly I have both build.sbt and plugins.sbt in my project and I'm not sure which one I should be putting the import into, does anyone know?
Also, I'm not sure why there even is the separate project module in my project, intelliJ created it as part of the project. Could anyone explain the purpose of the two separate modules and why they are there?
Thanks!
So, in sbt, you have your project. This is specified in build.sbt (or more correctly, any *.sbt file in your projects base directory). Any libraries that your applications code needs, for example, if your application needs to send emails using the commons email library, go in to the librarDependencies seeing in here.
But build.sbt itself is Scala code that needs to be compiled, but it's not part of your applications runtime. So in sbt, your projects build is a project itself, one that has to be compiled. It has its own classpath, which consists of the sbt plugins you're using, so for example, if you need a less compiler to compile your less files, that's not something that gets done at runtime, so you don't want your application code depending on that, it goes into your project builds libraryDependencies, which gets specified in project/plugins.sbt (or in fact any *.sbt in the project directory). So, once you add it there, you can use the Scala code it provides from build.sbt. IntelliJ imports this project for you so that you can have syntax highlighting and other IDE features in build.sbt.
But it doesn't stop there. How does project/plugins.sbt get compiled, where is its classpath? Well, your projects builds projects builds project is also an sbt project itself too... It keeps going down. IntelliJ stops at that point though, it doesn't keep importing these meta sbt projects because it's actually very rare to need additional sbt plugins for your projects builds projects builds project, so it just uses the same classpath as your projects build project for syntax highlighting in project/plugins.sbt.

IntelliJ - use imported modules as dependencies like maven projects in Eclipse

I've been asking myself this question for a couple of years but never really found the solution.
I used to work with eclipse (on maven java projects). I could import a project -let's call it 'proj-A'- and if one of proj-A's dependencies was found in the workspace with the same exact version, eclipse would use that project's source instead of the jar from the repository. This way I could edit a library and see the changes in the project that used it right away.
For example, in Eclipse, if proj-A depended on dep-B-1.2.3-SNAPSHOT, I could import proj-A and dep-B in the same workspace, and if dep-B version was 1.2.3-SNAPSHOT I could see the live changes in dep-B sources from proj-A classes.
I'm now working in scala in IntelliJ. I don't seem to be able to do that. what's the best workflow if you want to avoid publishing the library and then reloading the whole project that uses it along with all its dependencies every time?
If I import proj-A as sbt project I can find dep-B snapshot jar in the libraries (loaded from some repo, be it local or remote), and I can't see the code changes to the dep-B module imported in the same intellij project (i.e. the equivalent of eclispe workspace).
If I manually remove the dep-B jar and add the dep-B module as a dependency for proj-A I'm forced to do it everytime I reimport proj-A for some reason.
I'm not sure there's a way of doing this as straightforward as the eclipse way (automatic), but maybe you know something I don't ...
thanks
It should work out of box for dependencies, which are imported to the project as modules, no additional settings needed. At least for Java.
Just do not run a Maven goal, that would use dependencies from the repository.

Export eclipse project to build.sbt

I have a setup with 13 different eclipse projects (mostly scala and java). All projects have dependencies on each other in different ways. Now the project is starting to get big so we want to transition to a build tool and I wanted to try SBT.
First question: Is there any way to export the build files from eclipse? I mean, I have everything working in eclipse so It feels like an "export build.sbt" would be possible.
Second question: I have not found any easy way to add the project dependencies in a sbt file. Some sites say that I should publish all projects to a local maven repo and then using dependencies to be able to build it, but that requirement seems a little extreme.
I found my answers by a friendly person on the #sbt irc-channel.
For the first question: No, there seems to be none at the moment.
For the second qestion: I should create a multi-project build and define dependencies between projects that way (following the guide at: http://www.scala-sbt.org/release/docs/Getting-Started/Multi-Project.html)

Maven "Module" vs "Project" (Eclipse, m2eclipse plugin)

I'm a beginner at Maven and I've played with it from a command line point of view a little, so now I was trying to use it in Eclipse; I installed the m2eclipse plugin to do so.
But I'm stumped from the very beginning! Apparently I've missed a bit of terminology somewhere along the line. I can't keep track of all these new Maven terms... What is a Maven Project, and what is a Maven Module? These are my options when creating a new project in the Maven category in Eclipse.
They are basically the same thing, but with one difference.
When you create a module, you must specify a parent project.
When you specify the parent project, it adds a <modules> section to the parent projects pom.xml.
That section basically says to the parent project:
run every command I get against all of my modules first
So for example, if you run, mvn package on the top-level project, it will run mvn package against all its module projects first.
Hint:
Make sure all modules have high cohesion and related to each other, otherwise you will have a huge messy project without applying SRP (Single Responsibility Principle)
Found it! My searches were returning tons of hits for creating a "multi-module project", but once I added "-multi" to my query, the answer was on the first page.
According to Creating and Importing Projects:
m2eclipse provides the ability to create a Maven module. Creating a Maven module is almost identical to creating a Maven project as it also creates a new Maven project using a Maven archetype. However, a Maven module is a subproject of another Maven project typically known as a parent project.