On 23/07/2013, at 5:53 AM, Alex Ruiz <alr...@google.com> wrote:
> x
> Greetings everyone,
>
> We have, in Android Studio, a use case for retrieving multiple types of
> model, in single pass, from a Gradle project using the Tooling API. The
> following section explains the problem and the proposed solution. We
> discussed this issue and the potential solution with Adam during Gradle
> Summit back in June. Please let us know your thoughts. We plan to contribute
> this change to Gradle.
That'd be great.
>
> Thanks,
> -Alex
>
> Problem
>
> Currently, importing a Gradle-based Android project takes a considerable
> amount of time. The reason is that we have to make multiple calls to the
> Gradle Tooling API. For a project with N Android sub-projects, we have to
> make N+1 calls to Gradle. The reason is that an Android project may have a
> mix of Android sub-projects and plain Java ones and we cannot get all the
> Gradle models for such structure in one shot.
>
> What we are doing now is asking for the IdeaProject at the top-level project,
> then we iterate through the models of the returned IdeaProject asking for the
> corresponding AndroidProject, if it doesn’t have it, we assume is a Java
> project.
>
> Solution
>
> We are proposing is single-pass project import: a way to return all the
> models we need, from the Tooling API, in one invocation:
>
> ModelBuilder<GradleProject> builder =
> connection.models(IdeaProject.class, AndroidProject.class);
> GradleProject project = builder.get();
> // ‘models’ will have instances of IdeaProject and AndroidProject.
> List<Object> models = project.getModels();
> for (GradleProject child : project.getChildren) {
> // Each child will have its own models.
> models = child.getModels();
> }
This is a good plan. There are a couple of things I would tweak - more on this
below.
>
> Changes to Gradle Tooling API
>
> org.gradle.tooling.ProjectConnection:
> Add method ‘ModelBuilder<GradleProject> models(Class<?>...modelTypes)’. This
> change will allow us to query multiple models type as shown above.
`GradleProject` currently bundles together a few things about a project - its
place in the hierarchy, some identifying info, and the tasks of the project.
This would mean that for every model query, we'd need to create and configure
the tasks of each project. And this is something we'd like to avoid where
possible. I think it would be better if the API did not imply anything about
the tasks, and instead the tool can ask for them explicitly.
One solution would be to split up GradleProject into an interface that defines
the structure and some basic information about each project, and into a
separate model (or perhaps models) that provide additional, specific
information about the project. You can then ask for this extra information as
you would for any model of the project.
Another potential issue here is that there isn't necessarily a 1-1 relationship
between a Gradle project and an IDE project. There are many ways you might map
a set of Gradle projects to a set of IDE projects. It just so happens that our
IDE plugins current map each Gradle project to its own IDE project. But you
might, for example, want to map the integration tests of each Gradle project to
a separate `IntTest` IDE project. We want to allow the build some flexibility
over how each Gradle project is mapped to the IDE, so we don't really want to
bake a 1-1 mapping into the tooling API.
There are really several parallel hierarchies here - the set of Gradle
projects, the set of IDEA modules + IDEA project, and the set of Eclipse
projects. There is a relationship between a given Gradle project and IDEA
module, and a given Gradle project and Eclipse project.
>
> org.gradle.tooling.model.GradleProject:
> Add method ‘List<Object> getModels()’ to GradleProject. This change will
> allows us to retrieve the models available from a project.
What would be the behaviour when a requested model is not available? It would
be missing from the list?
--
Adam Murdoch
Gradle Co-founder
http://www.gradle.org
VP of Engineering, Gradleware Inc. - Gradle Training, Support, Consulting
http://www.gradleware.com
