Extensions vs ad-hoc component registration about commonmark

[colinodell]

Or, instead of an interface, perhaps we do an abstract class so you can override just the methods you need? I think that's what Twig does.

[dshafik]

I've implemented this almost identically (by accident) in #44, see:

• EnvironmentInterface: https://github.com/thephpleague/commonmark/pull/44/files#diff-4
• Environment::createEnvironment: https://github.com/thephpleague/commonmark/pull/44/files#diff-2604a7b7168c0a191cd22408d907dd44L218

[colinodell]

Nice! I really like how that looks.

Do you think we should call them Extensions instead and allow multiple to be registered? This would make it easier to mix and match different classes from different pacakges.

[colinodell]

If that doesn't make much sense then I'm fine with your approach @dshafik

[dshafik]

@colinodell on the surface, I like the idea of multiple, however there are some order of operations that matter when it comes to processing the markdown (see here) which would make it very difficult without having some sort of conflict resolution or complex ordering mechanisms (e.g. insteadOf(), insertBefore(), insertAfter() type thing)

[dshafik]

Just for the record, I think the correct way to do this for the end-user is to create their own Environment composed of whatever elements/parsers/renderers they want.

[colinodell]

Yeah, I think there's going to be 3 types of users and use cases:

1. User wants the default CommonMark stuff
2. User wants to use a different predefined set of parsers/renderers
3. User wants full control of everything

For that first group, Environment::createCommonMarkEnvironment() should be sufficient.

The new $environment->addExtension(...) method caters to the second group as basically uses the same approach you suggested.

And lastly, I've left the addXXParser and addXXRenderer methods intact for people who want to truly customize the environment to fit their needs.

All three methods use the same underlying principle of composing the environment with whatever bits you need.