Multi project build import forces full rebuild first time when invoking subproject only

Help/Discuss Buildship
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1

Can someone shed some light on this?

Here is what I did.

  1. I have a multiproject build, each subproject has already been built once and works fine
  2. Import the multiproject build into eclipse
  3. On the Gradle Tasks tab, invoke a single subprojects build command.
  4. The entire mutli project build (all subprojects) is attempting to be rebuilt at this point. It only does this once.
  5. OK now the entire project and all subprojects are built once in eclipse.
  6. Now invoking the single subprojects build command at step 3 only builds the subproject (what is wanted).

Why is this happening? The command line interface works as expected.

I need to turn this off somehow, is there a setting?

4

Hello Gradle team,

Here is a set of basic steps that will illustrate what I want to turn off (see step 6, can I prevent / control this?).

  1. Check out the project: git clone https://github.com/jbaranski/gradle-eclipse-multiproject.git
  2. In Eclipse, go to File | Import | Gradle | Gradle Project
  3. Fill in parent root directory field to wherever you put the project on your local machine, press next
  4. I specified local Gradle installation directory and local JDK home directory, the rest you can leave blank (this step may not matter but this is what I am doing), press next
  5. Preview generated, press finish
  6. At this point, each subproject gets built after the import, see the bin folder created and code compiled (why?)

System Details:

  • Eclipse Mars (64 bit)
  • Gradle 2.9
  • Java JDK 1.8.0_65 (64 bit)
  • Windows 7 (64 bit) and Windows 10 (64 bit)
5

If I understand you correctly, your concern is that Eclipse compiles your project and places the .class files to the bin folder, even though the Buildship import was used?

The short answer is that the Eclipse JDT and the Gradle build folder can’t be shared: JDT uses and internal compiler which is not replaceable and is very sensitive to changes. Say the build folder is shared the clean task is executed. The result is that all the class files are gone and you receive a bunch of build errors in the IDE.

6

Donat,

I don’t have an issue with that and understand why it’s necessary. I do have a problem with Gradle invoking the eclipse compiler for all sub projects if I’m running a specific sub task that has nothing to do with the other sub projects.

Does that make sense or am I explaining this poorly?

7

I’m not sure if my interpretation of your concern is any better, but I read it as you don’t like the effect of Eclipse’s “Build Automatically” being enabled, which really doesn’t have anything to do with Gradle or Buildship.

Let me re-state what I think you’re describing and see if you notice anything incorrect in order to verify:

  1. You have a multi-project build that has been built once using Gradle at the command line. There is a build folder, but not a bin folder for each subproject.
  2. You import the the multi-project build into Eclipse.
  3. Eclipse creates a bin folder and builds each subproject automatically in that bin folder because “Build Automatically” is enabled.
  4. You run a Gradle task for a single subproject which re-builds that subproject into the build folder only (but you notice the bin folders from step 3).

You can turn off “Build Automatically” in Eclipse if you don’t want this to happen. It will be necessary to run “Build Project” manually from the menu if you still want to see feedback in the IDE. Otherwise, you won’t see any code compilation errors until you run the Gradle build task.

To answer this question:

Eclipse needs to compile the classes somewhere (bin) in order to give you the instantaneous feedback as you edit the source files.

8

I’m not sure if my interpretation of your concern is any better, but I read it as you don’t like the effect of Eclipse’s “Build Automatically” being enabled, which really doesn’t have anything to do with Gradle or Buildship.

Let me re-state what I think you’re describing and see if you notice anything incorrect in order to verify:

Your interpretation and steps below it are close to correct except at step 3 the assumption that “build automatically” is selected, even though it’s not. Step 4 is incorrect in your scenario. The sub task will not even begin to start at all until the Eclipse compiler compiles each sub project source first. The compiler is being invoked by gradle buildship plugin. I cannot figure out why this is happening.

If you check out my example project and run through my steps you should see the issue I describe.

Eclipse needs to compile the classes somewhere (bin) in order to give you the instantaneous feedback as you edit the source files.

Yes I understand this.

9

Well, I think I know what you’re saying, although I can’t be of any help.

I actually had the opposite problem with your test project to start with. I couldn’t get Eclipse to generate the bin folder when I manually ran “Build Project” from the menu. I had to go back to “Build Automatically” and then manually run “Clean…” before the bin folder showed up.

10

Interesting. So let’s say you import my test project, no bin folders exist and no code was compiled by eclipse, so that’s fine. Now invoke a single sub project task, IE: the clean task, via the gradle tasks tab in eclipse.

At this point, does buildship invoke the sub project task only or did the buildship plugin first invoke the eclipse compiler and compiler all the sub projects source? I’m seeing buildship invoke the eclipse compiler for all sub projects first then runs the task. This only happens once (the first time). After that the sub project task that is invoked is run as expected (just like the command line).