Hey all,
> On 11 Nov 2014, at 0:39 am, Pierre De Rop <[email protected]> wrote:
>
> The improvements you are proposing would require a major version bump since
> it's an incompatible API change. But I personally like what you are
> suggesting, and I could quickly do it in the upcoming Dependency Manager
> 4.0.0, which is a new major version.
Agreed, we cannot introduce something like this any sooner than in version 4.
However, it is probably not too hard to implement this yourself on top of the
current release either, since 80% of what Christian is proposing is just
renaming existing methods:
If you create your own version of DependencyManagerBase and also wrap classes
like Component and ServiceDependency/ConfigurationDependency it is quite
straightforward to delegate from your new set of methods to the existing ones.
This goes in the direction that Paul proposes as well with the builder class.
> But before, I need to know if Marcel is agree to go ahead with all this; so
> for the moment, may be you can just create a Jira issue, and let's wait for
> Marcel to see if he's OK.
I am fairly neutral on this.
Yes, the proposed methods are better aligned with most fluent APIs. However,
two downsides I see is that it does break the existing API, making it harder
for people to migrate to version 4 (and, for various reasons, they should do
that). Also, you are not required to use the fluent style, in some cases you
end up invoking individual setter methods on DM components and in those cases,
the fluent style methods might look a bit strange.
Because of this, maybe we should explore the separate builder class that Paul
suggested!?
> Just one remark: the setters can be easily removed, however I think we
> can't manage to make the "component()" method automatically add the
> Component to the DependencyManager, because technically; when you add a
> Component to a DependencyManager, the Component is actually *activated*,
> and at this point, all the necessary dependencies have to be already in
> place.
Yes, and there are a few other scenarios as well where you don’t want to
combine creating and adding a component, so I think we should leave that part
alone.
> So, the only possible improvement I'm thinking about for now could have the
> form of this:
>
> public void init(BundleContext context, DependencyManager manager)
> throws Exception {
> component()
> .implementation(DataGenerator.class)
> .add(serviceDependency(Store.class).required())
> .add(serviceDependency(LogService.class))
> .addTo(manager);
> }
>
> (notice the addTo method at the end of the sample above, which could just
> add the fully built component to the DependencyManager "manager" object).
I don’t think that makes the code better. You still have two calls (one to
create, one to add) and if you forget the addTo(…) it will probably still be
hard to spot that that was the “bug”.
> but I propose you first create the Jira issue and see what Marcel thinks.
>
> I will possible add more suggestions in your Jira issue once you will have
> created it (like also using a builder pattern for the aspects/adapters:
> this would allow to reduce the number of method signatures for the
> createAdapter/createAspect methods).
>
> kind regards (and thanks for proposing to improve Dependency Manager :-))
Agreed, this is a good discussion, thanks for the input!
Greetings, Marcel
