API8 - Improve PlayerChatEvent

[Faithcaio]

SpongeAPI | Sponge
#2259

• adds an easy way to filter Audiences for MessageChannelEvent.
• PlayerChatRouter -> PlayerChatFormatter now only handles message formatting. Which is applied to each audience of a ForwardingAudience
• PlayerChatEvent extends MessageChannelEvent to handle the audience target replacing PlayerChatRouter

[dualspiral]

I've been talking to Faith about this as it's been done and this is a step up from where we were.

I do have a couple of thoughts on a slightly different approach and any feedback/thoughts on this would be welcome.

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For this, the intention is that chat formatters are chained. Would a list of formatters that are then executed in order, rather than chained, be better here. My thought was that plugins could inspect the formatters that other plugins have applied and make decisions based on that, so if I detected a chat router that came from UltimateChat, via some heuristic, for example, I might not want to apply mine at all. It should also be possible for a plugin to clear formatters from this list too

That might be complicating it a bit though. I don't mind not doing this, it's just an alternative, but it might not be all the useful.

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Protection plugins, such as GriefDefender, may only care about the end result of a message. Rather than having to go and execute the chat formatter on every audience manually, is there merit to create a second "post but not post" event after the formatting has been resolved? Something like:

interface PlayerChatEvent extends Cancellable {

    interface Format extends PlayerChatEvent {
        // this would be what we have now
    }

    interface Formatted extends PlayerChatEvent {

        /*
         * The Audiences that will recieve a message, and their respective message
         */
        Map<Audience, Component> messages();

        /*
         * Protection plugins could stop certain messages getting through to specific
         * audiences
         */
        void filter(Audience audience);        

    }

}

Protection plugins etc. that really only care to cancel something may appreciate this.