Bukkit/Spigot HeroChat 5: Custom Replacement in format string

This has been something that has eluded me for some time...

HeroChat, in its config.yml file, has a section called format:, under which you'll find a default format string. This is echoed in the config for each channel. This is an example of what mine looks like...

format:
  default: '{color}[{nick}]{title} {groupprefix}&f{sender}: {color}{msg}'

{color} represents the color defined in that channel's config
{nick} represents the channel's "nickname"
{title} is a custom formatting string
{groupprefix} is the prefix assigned to the player's Vault group.
{sender} is the display name (or nickname) of the player sending the message. {msg} is the message they typed into the console, after going through the built-in censorship.

So, how do you get {title} or whatever your custom string is to change? As I said above, this is something that I could not figure out for a long time. But, doing some research, I've figured it out and it's actually not that difficult. I'm leaving this here as a resource for Java developers running into the same issue.

I'll leave a step-by-step solution below. This tutorial assumes you are familiar with your chosen IDE and have a way to retrieve a player-specific or group-specific replacement string...

1. Load HeroChat.jar into your environment.
2. Create and register a new PlayerListener.
3. Add the following imports:
   • import org.bukkit.entity.Player;
   • import org.bukkit.event.EventHandler;
   • import org.bukkit.event.Listener;
   • import org.bukkit.event.player.PlayerJoinEvent;
   • import com.dthielke.herochat.ChannelChatEvent;
   • import com.dthielke.herochat.ChannelManager;
   • import com.dthielke.herochat.Herochat;
4. Add the following event:

@EventHandler
public void onPlayerChat(ChannelChatEvent event) {
    ChannelManager cm = Herochat.getChannelManager();
    String newFormat;
    Player player = event.getSender().getPlayer();
    String chatReplacement = plugin.classWithReplacer.replacer(player);

    // Simple replacement here. If it is equal to "", let it replace as
    // normal. If it actually has a value, surround it with brackets.
    if (!chatTitle.equalsIgnoreCase("")) {
        chatTitle = "[" + chatTitle + "]";
    }

    // When the channel being spoken in uses the default format,
    // asking it for the format returns "{format}"
    //
    // We do not need to escape the brackets because
    // String.equalsIgnoreCase does not use regex.
    if (event.getFormat().equalsIgnoreCase("{default}")) {
        // cm.getStandardFormat() returns the format provided in config.yml
        newFormat = cm.getStandardFormat();

        // IMPORTANT!! You MUST escape the curly brackets or your plugin WILL throw regex errors!
        // We escape with two backslashes because the java parser takes one away, resulting in \{ and \} respectively.
        // Then, the regex parser comes in and converts \{ into a safe {, and \} into a safe }
        // "your_replacement_here" should be whatever your custom tag is within the config.yml or the channel's config file.
        // In my case, this was {title}.
        // Note: the square brackets can be added to your config file, but I chose to add them here to avoid empty brackets
        // when the player did not have a title.
        newFormat = newFormat.replaceAll("\\{your_replacement_here\\}", chatReplacement);
    } else {
        // event.getFormat() returns the current channel's format or "{default}"
        newFormat = event.getFormat();
        newFormat = newFormat.replaceAll("\\{your_replacement_here\\}", chatReplacement);
    }

    // This method performs a "one-time" change to the default format.
    // Because you are providing the same format as the original, only
    // contextually modified for the player or player's group, the chat
    // output will still be determined by the global or channel config
    event.setFormat(newFormat);
}

And here's the complete (though uncommented) version

package your.package.here;

import org.bukkit.entity.Player;
import org.bukkit.event.EventHandler;
import org.bukkit.event.Listener;
import org.bukkit.event.player.PlayerJoinEvent;

import com.dthielke.herochat.ChannelChatEvent;
import com.dthielke.herochat.ChannelManager;
import com.dthielke.herochat.Herochat;
import your.package.here.MyPlugin;

public class MyPluginPlayerListener implements Listener {

    private MyPlugin plugin;

    public MyPluginPlayerListener(MyPlugin plugin) {
        this.plugin = plugin;
    }

    @EventHandler
    public void onPlayerChat(ChannelChatEvent event) {
        ChannelManager cm = Herochat.getChannelManager();
        String newFormat;
        Player player = event.getSender().getPlayer();
        String chatTitle = plugin.titlesConfig.getTitle(player);

        if (!chatTitle.equalsIgnoreCase("")) {
            chatTitle = "[" + chatTitle + "]";
        }
        if (event.getFormat().equalsIgnoreCase("{default}")) {
            newFormat = cm.getStandardFormat();
            newFormat = newFormat.replaceAll("\\{title\\}", chatTitle");
        } else {
            newFormat = event.getFormat();
            newFormat = newFormat.replaceAll("\\{title\\", chatTitle");
        }

        event.setFormat(newFormat);
    }
}