So in the new API, what kind of component would receive a mutable model if not a plugin? I.e., what would be the correct mechanism for enhancing the project model at runtime?
Matt On Mon, Mar 28, 2022, 4:33 AM Guillaume Nodet <[email protected]> wrote: > Hi everyone, > > Last week, I worked on a fully immutable maven model. The results are > available at [1]. The modifications required in modello were a bit too > complicated, so I ended up using the modello models, but generating the > models, readers and writers using velocity templates. The templates are > actually way easier to modify than the modello generators, as you can see > in the template generating the model [2] or the reader [3]. This also > allows generating mergers and transformers. > This also allows getting rid completely of plexus-utils dependency in the > API. > > This all looks quite nice to me, however those changes are definitely > incompatible, which means plugins will just break at runtime or compile > time if they try to instantiate or modify objects from the model. If > there's a consensus on trying to move forward with an immutable model, I > can investigate generating this immutable model into a separate new package > and only use it for the new API, and rewrite the mutable model by wrapping > the immutable one. This would allow a smoother integration / migration. > > Feedback welcomed ! > > Cheers, > Guillaume Nodet > > [1] https://github.com/gnodet/maven/tree/m-api-immutable > [2] > > https://github.com/gnodet/maven/blob/m-api-immutable/api/maven-api-model/src/main/mdo/model.vm > [3] > > https://github.com/gnodet/maven/blob/m-api-immutable/maven-model/src/main/mdo/reader-ex.vm > > Le lun. 14 mars 2022 à 08:59, Guillaume Nodet <[email protected]> a écrit > : > > > Hi everyone, > > > > As Michael hinted at this new API in the "[DISCUSS] Radical Fast Forward > > to 3.5.4" thread, I'd like to start the discussion around it. > > > > Over the past weeks, I've worked on an experimental API for Maven 4.x. > > The goals are multiple : > > * fix some problems with designs that do not work well with > > multithreading > > * offer a way to finally get rid of deprecated code > > * offer a complete API (which would deprecate m-artifact-transfer, > > m-dependency-tree) > > * offer an homogeneous and a bit more modern API > > * completely hide the maven-resolver, so that it can finally upgrade to > > a v2 with the package renamed without too much disturbance > > > > The goal would be to extract the models and API in a separate project > with > > a much lower release cycle, as those rarely change, but are currently > > released with each version of maven. > > > > The current API can be seen at [1]. Note that the plugins API has also > > been included within the new API and the plugin tools have been updated > so > > that the maven-plugin-plugin supports both v3 api and the new v4 api. A > > new flag has been added to the MojoDescriptor to know if the plugin is > > using the old or the new api. The plugin testing harness tools have been > > updated to junit 5 and now provide a few annotations [2] to help writing > > plugin tests [3]. The maven-core has been enhanced to support loading > > those new v4 plugins along with the v3 ones, which means they can work > > side-by-side in the same build. This is done by implementing the new API > > by wrapping the v3 implementation classes (such as MavenSession, > > MavenProject, etc...) [4]. > > I've ported a few plugins such as clean [5], install [6], deploy [7] as a > > proof-of-concept that this actually works. > > > > The very rough goal would be to to have multiple phases: > > * continue the work on this API so that it can actually cover all use > > cases for plugins, create a new project with the new API and models, make > > sure plugins can work correctly with the new API / implementation > > * release the API, then maven-core supporting the new API > > * upgrade plugins to the new API, deprecate old components and API > > * once all plugins have migrated to the new API, switch maven-core > > implementation to the new API > > > > I'm eager to hear your thoughts ! > > > > [1] > > > https://github.com/apache/maven/tree/mvn4/maven-core-api/src/main/java/org/apache/maven/api > > [2] > > > https://github.com/apache/maven-plugin-testing/tree/mvn4/maven-plugin-testing-harness/src/main/java/org/apache/maven/api/plugin/testing > > [3] > > > https://github.com/apache/maven-deploy-plugin/blob/mvn4/src/test/java/org/apache/maven/plugins/deploy/DeployFileMojoTest.java > > [4] > > > https://github.com/apache/maven/tree/mvn4/maven-core/src/main/java/org/apache/maven/internal/impl > > [5] https://github.com/apache/maven-clean-plugin/tree/mvn4/ > > [6] https://github.com/apache/maven-install-plugin/tree/mvn4/ > > [7] https://github.com/apache/maven-deploy-plugin/tree/mvn4/ > > > > -- > > ------------------------ > > Guillaume Nodet > > > > > > -- > ------------------------ > Guillaume Nodet >
