Add preFileDownload event on packages.json fetch

[JJK801]

Hi,

In order to extend @naderman's work on pluggin system, this add a PreFileDownloadEvent dispatch when composer fetch packages.json (For ComposerRepository class).

It's usefull for us, because we need to fetch it using s3:// scheme.

Thanks,

Jérémy

[stof]

is there a use case for making it nullable ?

[JJK801]

not really, just following the existing ;)

[stof]

I see a drawback in this PR: it introduces some cyclic dependency graph: Composer depends on RepositoryManager which depends on EventDispatcher, which depends on Composer. This is not really clean

[JJK801]

I just reorganized this code, in order to make possible to inject EventManager into RepositoryManager, but i saw it and your right, it's not really clean.

[omansour]

👍 will allow us to secure our packages.json file on our instance of satis

[omansour]

see https://github.com/naderman/composer-aws/pull/5/files

[Seldaek]

@stof it's not great but I'm not sure there is a way around this.

[Stelian]

Breaks entirely: #2444

[fadoe]

(:-1:) Same problem here.

[robertfausk]

👎 :-(

[JJK801]

Why does VcsRepository break standard repository composition? is this argument ($driver) really used?

[JJK801]

#2446