Multi-project Play framework applications in IntelliJ - maven

I’m using IntelliJ to develop a Play application. The application has several maven dependencies developed in house, some of them being marked “SNAPSHOT" meaning I want to see changes made in them immediately.
Now. When I make changes to the SNAPSHOT dependencies in IntelliJ, my Play Application doesn’t pick them up undil I build and install the modified artifacts (using maven) and trigger an SBT-build of the Play project. Otherwise the application doesn’t see my changes.
Is there any way for my Play application to resolve dependencies locally, without me having to do an install and build every time I modify one of the maven projects?
Cheers,
- hugi
PS: For those familiar with the Eclipse way of thinking, that’s kind of what I’m looking for. There I can split my project up into multiple modules and have Eclipse worry about resolving my dependencies in the workspace.

There is no easy way for this to magically work that I know of, however there are several alternatives that can ease your pain - use maven plugin for play:
maven-play2-plugin
http://nanoko-project.github.io/maven-play2-plugin/maven/release/
This one takes your dependencies and copies them into lib directory, where play picks them up. Still uses sbt to build play part of your application - that is the main disadvantage, you need to maintain 2 builds.
You still need to build your dependencies and then copy them to lib (using copy-dependencies command), but your IDE sees everything immediately.
play2-maven-plugin
https://code.google.com/p/play2-maven-plugin/
Everything is built by maven, but doesn't support play auto-reloading - you need to build & restart whole play project every time you make a change, which is kind of back to square one.

Related

Why refresh of Maven repository is not enough for IntelliJ?

I had a NoClassDefFoundError problem with some test, launched from IntelliJ. In order to repair the situation, I had to make several changes in many poms of the project - adding new packages and excluding some old ones for to escape the overlapping of them. Also, I reapired the situation with different versions. But the situation did not improve. Again, some package, declared in pom, was not found where it should be.
I refreshed the maven repository by
mvn -e clean install -U
, as is advised in https://stackoverflow.com/a/9697970/715269 - so old and upvoted answer, that it surely looks as Santa.
The problem remained unchanged.
I output the maven map. It was correct and it contained all needed.
I looked at the list of the External Libraries of the project. It was the old uncorrected list of overlapping jars with same names and different versions, and without good packages I added just now, and well seen in maven tree output!
Already hapless,
I reimported packages in IntelliJ
by:
Ctrl+Shift+A, Reimport All Maven Projects.
Ho! The list of libraries got repaired. And the problem, mentioned in subj, disappeared.
The question is: How it could happen, that the same project has that very pom for everything, but gets packages differently being launched in maven and in IntelliJ?
I know about that feature "delegate IDE build to Maven". And I keep it turned off. But I am NOT talking about the different SW for building. Whether they are different or not, they should be up to the actual pom's. And whereas maven, if turned off from the automatic building won't know about changes in poms, IntelliJ KNOWS about them. It could have jars up to pom, or up to maven - it has sense, but it simply has some old rubbish. Was there some deep thought under that construction?
Every time you manually change the pom.xml file, including the dependencies you need to load these changes into IDE. IDE does it on Reload from Maven action. See also Import Maven dependencies.
Intellij doesn't use maven to bulid and run a project except you are delegating build and run action to maven:
Since, IDEA doen't really use maven to run and build, it uses the pom.xml to import the project structure and "tries" to build the project the same way was maven does.
Actually, there are quite a few differences between these to build processes.
Generating sources or filtering resources (don't know if this is still an issue) aren't done during building the project with Intellij IDEA.
In case you are using code generation you have to build the project via maven first and then - when all the resouces are filtered and additional sources are generated - you are able to run, debug aso. the project with Inellij IDEA.
That's an important thing to be aware of and that's the reason why maven and IntelliJ IDEA project structures might get out of sync.
You can enable the "Reload project after changes in build scripts" feature and select the Any changes checkbox to keep your project structure updated:
Why should you disable this feature anyway
If you are working on a build file (gradle or maven is not important) reloading the structure on any change can be very anoying. It's cpu intense, dependcies are fetched aso.
Therefore, I prefer to reload project structure only in case of an external change. This happens when pulling an updated version of the build file for example.

Library development/debug with Maven

I am in the processing of integrating Maven into my my projects. While maven has plenty of pros i'm finding it difficult to figure out how to maintain my current development process, which is as follows:
For creating SDKs I will create a sample app, which will depend on and directly reference the SDK source code, all from within the same code project. This means that I can make easily change/debug the SDK code with one click run/debugging.
I fear this won't really be possible with Maven. Can I create some type of Hybrid approach, where I continue my normal development approach and then push builds to Maven when it is appropriate.
Update - For Clarity
My problem is that when everything is done through maven, the dependencies are built and published to Maven. Then, the dependent project pulls down compiled references and uses them. My issues is that I don't want to go through this whole process every time I make a small change to a dependency.Thanks.
You should try creating parent level pom.xml with two modules - your library and simple app to test it. In simple app's pom.xml provide a dependency on library module.
Then open in your IDE parent pom as maven project. This should be sufficient for normal debug.
Other possible approach - install you library artifact into maven repo with sources. In this case you will be able to debug it, but test app still have to load use jars from repo.

How to define gradle project as library dependency in Play?

I have a project, which is written using the Play Framework, say myproject-web. It is mostly a thin HTTP layer over another project, which forms the core of the entire business logic, called myproject-engine. In my build setup, myproject-web is a sbt project, whereas myproject-engine is a Gradle one.
What I want to achieve is that Play recognize myproject-engine as a dependency, and invoke gradle to build it whenever I try to build the play application (either on run, or automatically, as it happens in the dev mode) or when I do play dist. Is it possible? What is most important for me is that it automatically loads any dependencies that myproject-engine has.
Eventually, the state I want it to reach is that I host my Maven repo for these projects and then SBT can simply pull this package from over there and will get all its dependencies. Is this rather easy to setup? Even if it is, is it relatively easy to maintain?
As #Peter-Niederwieser pointed out in his comment, I think the only viable solution is to have a maven/ivy/gradle repository where the myproject-engine Gradle project is published to. With the correct resolvers the project becomes yet another project dependency, regardless of the build tool it uses.
See Resolvers in the official documentation of sbt.

Update dependencies while in hosted mode in GWT

I have a GWT webapp split into two Maven projects where one is a dependency to the other. Each time I change something in the dependency and I'm running webapp in hosted mode I have to rebuild the subproject and restart hosted mode for changes to apply. It takes a lot of time so I'd like to ask you if there is any way to make GWT using "live" version of the dependency?
There are 2 cases:
for server-side code, assuming you use the DevMode's embedded server, rebuilding the app and then refreshing the server should be enough
for client-side code, AFAICT, you have to use the source and output directories of the dependency module rather than the JAR containing them (GWT will load the source from the classpath, but apparently it'll only see the modified sources if it comes from a folder rather than a JAR; at least that's what I found in my tests). This goes against The Maven Way™ but the only solution so far is to use a special profile that will import the sources of the dependency project as sources of the project you're running. You can see examples of that in my archetypes.
There's actually a bug opened for the gwt-maven-plugin, MGWT-332, to do that automatically when running a reactor build. I also mused about what's really needed, for the forthcoming official gwt-maven-plugin (rewritten from scratch, independent from the CodeHaus Mojo plugin).
If your dependency does not come from a reactor build, then you're out on your own: you chose to make it totally distinct, so that's how it'll behave: you'll have to release it (even a snapshot) each time you make a change to it, and use the new version in your app (which means re-launching the DevMode).
This can be circumvented by running DevMode on your own, without the help of the gwt-maven-plugin. You're left on your own managing the classpath though (using the Google Plugin for Eclipse, I suppose you could simply edit the launch configuration to add the source folders of your dependency project to the classpath, before the classpath provided by Maven, that would reference the JAR).
Remove the dependent other application jar file from the primary application lib folder under webapp.
Eclipse should then resolve the dependency using the other project in the workspace if you have added it to your primary application classpath.
As GWT build takes ages, we invested some money in a JRebel license. We have two separate Eclipse projects for our back-end and our GWT front-end. JRebel reloads the classes automatically and I never need to restart my local server while writing code. It proved to be a wonderful time saver. Definitely worth the investment.

How to have different build task and dependency "on-demand" with Maven

Hi there i need some information or general tips on a problem with maven.
Context:
We just migrated one big eclipse project into 4 maven project. (Thats one step in the good direction!)
We were building that/those project with an ant script (build.xml) We were selecting the task to do "on-demand"
To keep it simple here are the 4 project : Core, Client, Server, Admin.
Each of those maven project build into a jar. This have been establish and it is working perfectly. Core is a dependency to Client and Server.
We use Jenkins-CI and Artifactory on a remote server.
Problem:
I need to create some kind of "parent project" that will build all those other maven project and add some task "on demand" that we were doing with an ant script.
Exemple: We want to build locally (So we don't use jenkins and artifactory on this side) for our developper so they can test manually their update (yes we have no test for now, we are working on a legacy system). On this build, we do not want to obfuscate the code or sign our jar..etc
We also want a "customer build" (The real release that we push on the server, so it does use jenkins and artifactory) That will add some task on some of the 4 project like obfuscating the code, signing the jar ..etc
For this "customer build", we need to be able to select our dependency of a library "on-the-fly" or more like "On demand". Our program is an extension to another software and all our customer don't use the same version. To make it simple the library "y" can be y-2.0.1.jar or y-2.0.2.jar.. etc
All of those "task" i need can be done in different maven-plugin with no problem.
Question: What would be a good practice to solve my problem. We would really like to get rid of our ant script. Also we are cleaning a big big dirty project so i would like a clean solution without a lots of duplicated stuff or lots of manually task to do each time we want to build either locally or on the remote server for our customer.
Idea: I though i could use different maven profile in all those 4 project as i saw there:
Ant to Maven - multiple build targets But i will have a seriously huge pom.xml for each project with lots of duplicated stuff so I really don't like this idea. I though we could have a parent maven project but this would contain no code so i think I'm wrong with this idea also.
Thank for answering and for your time!
Going with Maven Profiles is the right thing to do for this kind of customization. Then you'll probably have developerProfile and releaseProfile or such.
And yes, your poms will be big and complicated.
Looks like your demands are a little bit to much for what Maven can provide out-of-the-box, and it's not the best tool for doing highly-customized builds. Since (as I understand) you are on pretty early days with your new build infrastucture, I'd advice to look at Gradle. You could reuse your ant tasks and both Jenkins-CI and Artifactory work great with Gradle.

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