FilterPlus

Filter content and censor profanity from public chat stream. Includes API for external mods, moderation tools, self-regulating utilities, and more.

Copyright © 2023-2025 monk (Discord ID: 699370563235479624)

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Filter

• Multi-pass filtering logic and validation.
• Censor profanity with asterisks(*).
• Clean messages before broadcasting to public.
  • Excessively long words
  • Excessive repeating characters
  • S p a c e d o u t w o r d s
  • Hyperlinks, emails, phone numbers
• Non-intrusive pre-filter string sanitizing.
  • If not censored, message is delivered as-is.
• Simple API callback for external mods.

Plus

• Message highlighting for players mentioned by name
• Proximity messaging with players within 100 nodes
• Stop unwanted messages by blocking them
• Moderate players arguing by blocking each other
• Moderate spammers by chat timeout
• Toggle public chat, and still accept direct messages
• Optional nametag flair from external mods

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Filter and Censor

Messages sent to public chat are filtered for profanity. Messages sent to other channels, such as private or group messaging, is left unfiltered.

There are a total of four filter lists constructed by the filter.

blacklist_patterns.lua: These words will be made into patterns. The list shouldn't be too long; more patterns increases processing time.

blacklist_explicit.lua: Explicit validation of words captured by pattern, and overrides the whitelist.

blacklist_mutations.lua: Repurposed spell-check which will mutate words hundreds of different ways to supplement the explicit blacklist. Add words with caution.

whitelist.lua: If the context words captured are not in the whitelist, they will be censored.

filter_api.lua: This is the main script containing closures to load the filters and process incoming messages.

filter_cli.lua: For porting or testing, a standalone version of the filter and API is provided.

sanitizer.lua: Heavy pre-filter sanitizer to facilitate the process. Messages will be sent as they were received if not censored. Before curse detection, the sanitizing function will:

1. Replace symbols and non-standard ascii to a alphabetic equivalent
2. Merge words with hyphens and apostrophes (you're -> your)
3. Replace embedded number with alphabetic equivalent
4. Replace any remaining non-letter symbols with a space
5. Strip away excess spaces

clean_message.lua: A pre-sanitizing function intended to remove spammy formatting and content from a message before sanitizing. It can be used independent from the filter and will modify a string by:

1. Lower-casing the entire string
2. Join words separated with s p a c e s
3. Strip hyperlinks, email address, phone numbers
4. Clip words exceeding 23 characters
5. Remove excess repeated charactersssssss

Chat Commands

/block

• Stop public and private messages from being delivered.

• Persistent between logins until unblocked or server shutdown.

/block or /unblock: Without parameter will show your list of blocked players.

• Players with staff privilege are not able to block or be blocked. Using the block command with player name will list the player's block list.

/block player_name or /unblock player_name: Add or remove another player from your blocked-players list.

/forceblock player_name1 player_name2: Add two players to each other's block list. Requires mute privilege.

/mute

• Timeout player from using public chat.

• Does not mute private messaging, faction messages, or proximity chat.

• Retroactively applied to alt-accounts using a 24-hour cache.

/mute player_name minutes: Defaults to 2 minutes if no parameter is provided, and 120 minutes maximum

/unmute player_name: To allow using public chat before timeout expires.

/chat

• Toggle seeing the public chat channel.

• Direct messages and group messages (eg, faction and proximity) are not affected.

/chat: No parameter is needed

/msg

• Overrides the default /msg command for compatibility with FilterPlus features

• Shows the sender their own message after it is sent.

/msg message contents: not censored

• Prefixed with #/pm «PlayerName» and colored green for incoming, blue for outgoing messages.

/xm

• Proximity chat allows a distance limited conversation.

• Players within 100 nodes will see these messages in a cyan color, prefixed with #/xm «PlayerName»

/xm message contents: Usage is similar to a private message, is censored

Note: to disable censoring /xm messages, modify the register_on_chatcommand from:

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Nametag Flair

Nametag default format is: «PlayerName».

Supports tags from mods if available: Ranks, Factions, Exp.

Ensure the minetest.conf has the setting enabled, and that a callback exists in the global namespace:

# minetest.conf
filterplus_ranks = true
filterplus_factions = true
filterplus_exp = true

-- nametag_flair.lua
local factions_available = core.settings:get_bool("filterplus_factions") and
    core.global_exists("factions") == true

A supporting mod should have a callback to provide variables to be used as the nametag flair.

There should only be two variables provided: text, and optional color.

For example, the Factions mod would have a callback defined within itself. FilterPlus will attempt to call the external mod, expecting to receive a hex color and a text string:

-- ensure compatibility with your mod
local get_player_faction = factions_available and factions.is_player_in or function() return nil end

-- expects a string, and hexadecimal color
local faction_name, faction_color = get_player_faction(name)

-- the resulting flair will appear as colored string in brackets, eg: [Faction]
local faction_tag = faction_name and "[" .. colorize((faction_color or "#FFFFFF"), faction_name) .. "]" or ""

The default ordering of supported flair tags is: {Rank}[Faction](Exp)«PlayerName»

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Highlighted Mentions

Messages containing online player's name will be sent to the mentioned player as green text. If many players are mentioned, they will each receive green text.

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API

To filter and censor content from external mods, such as signs or login names, include a callback containing the string to be filtered in the external mod:

filterplus.filter_check("Some text to be filtered")

The API will return the string, censored or not, with boolean true or nil to indicate whether the string was censored:

return "Some text to be ********", true

or

return "Some text to be filtered", nil

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CLI

The file named filter_cli.lua can be run as an independent tool, and can be imported to other applications if desired.

Simply run from terminal: lua filter_cli.lua

Receives user input and display the output of the filter as well as the API result.

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Version 0.2.0