I am new to scala, when I create a scala project in intellij it took really so long to download all the jar files. I have installed the scala plugin for idea IDE. Could anyone please tell me what should I do to get on the right track? Thanks very much.
Since the scala language is really a library on top of the JVM, creating a scala project for the first time requires the download of the specified scala version from a maven repository (usually this is at least the compiler and library, which for 2.10 comes to ~20MB). This will happen the first time, even if you've installed that same version of scala on your machine outside of sbt.
Once you go through this the first time, though, the next project you create--whether via sbt on the command line or via an IntelliJ sbt project--will pull these dependencies from your local ivy cache instead.
However, should you change the language version in your project, it will once again have to download the full language dependencies for that version.
In the screenshot it try to download the source files of one of of the dependencies. That mean it will try to download not only the compiled jars, but also it's source and docs.
only after downloading all of them, the project will be ready.
Disable to downloading of the sources and docs, and it will be much faster. How to disable it depends on how you create the project. (eg if you create sbt project, make sure to uncheck the "download sources and docs" in the creation/import wizard)
Related
Is there a definite doc somewhere that explains all the magic that happens behind the "Typesafe Activator" generation of "IntelliJ supported" project?
The sbt build files look absolutely monstrous, and I have no idea what and where IntelliJ looks for.
This is frustrating as working from two different PCs the scala seed project refers to different hard-coded paths.
Is there a good place to start?
Last time I checked, the typesafe activator was using SBT as the underlying build tool. When creating an intellij project it would thus use the sbt-idea plugin.
I guess a possible place to start would be that plugin's documentation.
However I think there is something else going on here. I think you have the activator installed on two different PCs and are trying to share the project between both PCs whether using version control or copying the folders.
The sbt-idea plugin will indeed write some absolute path in ideas project files (most likely the absolute paths to the sbt managed libraries in the ivy cache of your home folder) since this is required for the intellij project to work.
There should be no reason to "share" the idea project files, these should be considered computer specific and should not be checked into source control, or expected to work when copied from a random computer to another. You are expected to regenerate them for each computer the project is worked on.
If that sounds like a burden, you may want to install the Intellij scala plugin. Once installed, the sbt integration will allow you to import any sbt project even if you haven't generated the intellij support in the activator. Have a look at the features page, there is a video showing how to use the plugin.
Novice SBT question - Now that I've started with some basic SBT tutorials, I'd like to start using SBT build files (within Intellij) a lot more often. However, there's a couple of problems with this :
1) Existing projects that I currently publish to a jar, and later import into other projects... how do I publish this jar file to my local repository? SBT publish-local doesn't seem to fit my situation, because the project was made in Intellij and is not (yet) an SBT project.
2) Suppose I do convert the project to an SBT build setup (and then import it into Intellij).. how do I configure Intellij to to publish-local (update) each time I build the project? I do not see many configurable settings around SBT within the new Intellij SBT support.
Using Intellij 13 and SBT 0.13.1
Thanks!
to get you started up quickly on using SBT to drive Idea, have a look at my template project called skeleton
It supports most of the basic tasks you'd want to do.
To publish to your repository, use the publish task.
hope that helps!
For publishing, you simply use the publish action:
To specify the repository, assign a repository to publishTo and optionally set the publishing style. For example, to upload to Nexus:
publishTo := Some("Sonatype Snapshots Nexus" at "https://oss.sonatype.org/content/repositories/snapshots")
As for your second question, despite being a JetBrains fanboy, I have found SBT integration quite disappointing. For one thing, as the JetBrains documentation states itself, you need two plugins: their plugin and sbt-idea. You use sbt-idea to synchronize the IDEA module structure with the SBT build, and you use JetBrains' idea-sbt-plugin to execute SBT tasks in the "Before Launch" action in Run Configurations.
It sounds like you want to do an "install" on every build, so "Before Launch" action support isn't useful. I would suggest writing your own custom SBT task to install on build and using the Command Line Tools Console to execute that task with SBT as if from the command line. I know; that indirection is annoying.
Bear in mind one more thing. I have found numerous bugs with idea-sbt-plugin. At least on Mac. JetBrains told me the next version will be much better, and you can see for yourself with the next EAP version.
I certainly welcome others who have managed to have more success than I have to chime in.
I have recently completed the Scala course on Coursera, and since then I have been looking forward to getting my hands dirty with Scala again. I have written code for some years but I neither educated to be nor work as a programmer, so it took me a while to get a good opportunity but now that I have some time to invest and a good project to work on it's time...
Except I can't seem to get things set up properly, which I find really frustrating. I have OpenJDK 1.7.0_25 running on my Linux machine. I have downloaded and installed the Bundle Scala IDE build for Eclipse (just like we used in the course). And I got ScalaTest both as a jar file and the Eclipse plug-in.
I have a simple project (so far) and no matter what I do I can't seem to get my builds and tests in order. First off how exactly am I supposed to set up my project so that my classes and tests are actually run properly? All the assignments we got were projects that had the same structure, so do I have to have:
project
|--src
|--main
|--scala
|--test
|--scala
structure? If so why is it not the default way the project is setup when I create a new project? Do I create these folders manually, as packages or as source folders? The whole thing gets pretty murky..
I should mention that I tried to "Mavenize" the project using the contextual menu in Eclipse, added my ScalaTest dependency. The first thing that happens is that I get compile errors, at every point of dependency in my code. So clearly the library is not visible, in other words Maven does not seem to be doing much of management. I thought the whole point of Maven was to get and maintain dependencies as the project evolves. I concluded that I do not fully understand the way Maven works and thus I eventually gave up on Maven, once again, and went back to doing things manually.
Secondly, I can't seem to run my tests; the Run As... menu item does not include ScalaTest as it's mentioned in the documentation of ScalaTest Eclipse Plug-in. I have double checked that the plugin is installed. If I instead try to run using JUnitRunner then my tests are not recognized as valid tests. I have JUnit and ScalaTest on my build path, so it's got to be something else.
I suppose my overarching question is as follows:
given the Scala IDE build of Eclipse and ScalaTest, just exactly how am I supposed to set up my project (in Eclipse) so that I can just focus on writing my code and testing it, and hopefully not have any other headaches?
I work alone, and this project is not a product I need to deliver to some client. In other words I do not need to adhere to strict professionalism here. Honestly I just want to be able to code, get better acquainted with Scala and hopefully build a small data analysis tool that I will be using from time to time.
Thanks in advance!
Try using the sbt eclipse plugin:
https://github.com/typesafehub/sbteclipse
This is of course assumes that you use sbt as you build tool. If you don't at the moment you can find instructions on installation and usage here: http://www.scala-sbt.org/
Personally I've been using typesafe giter8 template (https://github.com/typesafehub/scala-sbt.g8) to setup my Scala projects, and then I use the sbt plugin mentioned above to generate eclipse project files.
Scala is somewhat Maven-based (sometimes implicitly), that's why you use that structure.
The easiest way I think is to create a simple Sbt/Maven POM and create the Eclipse project configurations (like with sbt eclipse). There you can set the dependencies (like the actual version of JUnit, Scalatest to use), so you can use the ScalaTest plugin easily.
In case of other issues, feel free to ask at the ScalaTest mailing list, Chee Seng and Bill Venners can help you a lot there.
The Scala IDE website has a full documentation on how to run unit testing frameworks with the IDE, have a look ! If you find missing elements, the bug tracker of the scala-IDE project is here.
I have near zero knowledge of Maven/Ivy but know that these technologies are behind SBT's ability to download and manage libraries automatically.
When I was trying to generate an IntelliJ Idea project from SBT it (Idea or the generator plug-in) has failed to find cached libraries stored in the common Ivy 2 cache. I've solved the problem by setting up the SBT project to use the old scheme storing downloaded libraries under the project directory. Another project of mine uses old SBT version which does it this way by default. In both cases I use clean command to remove library binaries before backing up and update after to download all the libraries again. Which means I download the same library files many times.
The question is how to set up a local repository to cache the libraries so that SBT update will download the libraries from the local cache if available? Would be nice to use the existing ~/.ivy2/cache directory for the cache if possible.
I tend to believe this is probably fairly simple when you have at least basic Ivy 2 knowledge.
Ivan, this may help.
sbt
> deliver-local
[info] delivering ivy file to /.../target/scala-2.9.1/ivy-1.0.xml
Then, you'll need to find IntelliJ equivalent steps, but in Eclipse you configure the build path with an additional library, "IvyDE Managed Dependencies" offered by the IvyDE plugin
1) browse to the target/scala-version/ivy-1.0.xml file
2) select desired configurations (compile, runtime, test, provided, etc.)
Now you have an ivy representation of your sbt configuration.
This works wonderfully with one annoying exception: on "sbt clean", ivy config file gets blown away and you have to repeat the above. Eclipse project clean preserves ivy config, btw.
Keep posted if this approach can be applied to IntelliJ
I am new to sbt and the sbt-idea plugin. I created a new project with the plugin and when opening the generated .idea file inside IntelliJ and compiling I am getting that "please specify compiler in Scala facet". When looking on the scala compiler facet all I see is "buildScala" in red.
Since I saw many here are using the plugin, can you explain the steps you took to correct this?
I have this problem when I use the sbt-idea processor, and then import the module into an existing IDEA project. However, when I open the project created by sbt-idea I do not have the problem.
I have not been able to fix the red buildScala problem with imported modules. I suspect it would require tomfoolery in the project files, as I can't find config options to correct it via the GUI.
Personally, I always install sbt-idea as a processor in every new SBT install I make. (See "Usage as processor" in the previous link). Then the correct way to generate project files is simply sbt idea.
Can you clarify exactly the steps you followed that led to the error?