Area 51

This page is for the development of documentation for Lua API functions that are currently being worked on. Ideally the entries here can be created in the same format as will be eventually used in Lua Functions and its sub-sites.

Please use the Area_51/Template to add new entries in the sections below.

The following headings reflect those present in the main Wiki area of the Lua API functions. It is suggested that new entries are added so as to maintain a sorted alphabetical order under the appropriate heading.

Basic Essential Functions

These functions are generic functions used in normal scripting. These deal with mainly everyday things, like sending stuff and echoing to the screen.

printDebug

printDebug(msg, [showStackTrace])

Prints a debug message in green to the error console in the script editor only. Does not echo to the debug window or the main console. Includes stack trace if showStackTrace is included and not nil or false.

See also

printError, debugc

Available in Mudlet4.14+

Note: This will not be echoed to the main console even if the option to echo Lua errors to the main console is turned on. Does not echo to the debug window. As such you can use it for debugging information without fear it will be shown unless someone goes looking for errors.

Parameters

• msg:

string to echo to the error console

• showStackTrace:

(optional) boolean true if you want to include the stack trace, leave off if you do not.

Example

-- print a debug message to the error console for troubleshooting purposes, when you don't want to echo the information to the main screen.
-- the only difference between this and debugc is this includes information on the script/alias/trigger/etc and line it was called from, whereas debugc does not.
printDebug("Switching to chaos mode")

-- Want to record that something occurred, and include stacktrace so you can see what path the code was taking, but you don't want to halt execution or have it show up in main screen or in scary red.
printDebug("Something unexpected occurred but we can recover from it. Still, we want to be able to notice and troubleshoot it with extra information.", true)

printError

printError(msg, [showStackTrace], [haltExecution])

Prints an error message in red to the error console in the script editor. Can optionally include stacktrace information and halt execution.

See also

printDebug, debugc

Available in Mudlet4.14+

Note: This WILL be echoed to the main console if the option to echo Lua errors to the main console is turned on. You should not use this for idle debugging information, but actual errors that may put big red error lines in the main window.

Parameters

• msg:

string to echo to the error console

• showStackTrace:

(optional) true if you want to include the stack trace, leave off if you do not.

• haltExecution:

(optional) true if you want to halt execution. You must pass a value for showStackTrace in order to halt execution.

Example

-- print an error message but do not include extra stack information or halt execution.
-- this is similar to debugc except it include more information on the place it was called from
-- and will show up in red and echo to the main console if the option for errors to echo there is selected.
printError("Your maxhp is below your currenthp and our game doesn't allow for that. HAX?!")

-- Something bad happened, for sure, but your script can recover.
-- Make sure this is something important enough it might make it to the main window as a big red error.
-- but we are not halting execution, since we can carry on in some capacity
printError("gmcp values for this thing went missing, will carry on using defaults but you should tell somebody about this.", true)

-- print an error message to the error console for troubleshooting purposes. 
-- Prints stack trace for troubleshooting and halts execution (because you cannot continue without the configuration, presumably)
-- similar to using error(msg) but includes the stacktrace information.
printError("Our entire configuration seems to have gone missing!", true, true)

Database Functions

A collection of functions for helping deal with the database.

Date/Time Functions

A collection of functions for handling date & time.

File System Functions

A collection of functions for interacting with the file system.

Mapper Functions

A collection of functions that manipulate the mapper and its related features.

mapSymbolFontInfo

mapSymbolFontInfo()

See also: setupMapSymbolFont()

Note: pending, not yet available. See https://github.com/Mudlet/Mudlet/pull/4038

returns

• either a table of information about the configuration of the font used for symbols in the (2D) map, the elements are:

• fontName - a string of the family name of the font specified
• onlyUseThisFont - a boolean indicating whether glyphs from just the fontName font are to be used or if there is not a glyph for the required grapheme (character) then a glyph from the most suitable different font will be substituted instead. Should this be true and the specified font does not have the required glyph then the replacement character (typically something like �) could be used instead. Note that this may not affect the use of Color Emoji glyphs that are automatically used in some OSes but that behavior does vary across the range of operating systems that Mudlet can be run on.
• scalingFactor - a floating point number between 0.50 and 2.00 which modifies the size of the symbols somewhat though the extremes are likely to be unsatisfactory because some of the particular symbols may be too small (and be less visible at smaller zoom levels) or too large (and be clipped by the edges of the room rectangle or circle).

• or nil and an error message on failure.

As the symbol font details are stored in the (binary) map file rather than the profile then this function will not work until a map is loaded (or initialized, by activating a map window).

setupMapSymbolFont

setupMapSymbolFont(fontName[, onlyUseThisFont[, scalingFactor]])

configures the font used for symbols in the (2D) map.

See also: mapSymbolFontInfo()

Note: pending, not yet available. See https://github.com/Mudlet/Mudlet/pull/4038

Parameters

• fontName one of:

• - a string that is the family name of the font to use;
• - the empty string "" to reset to the default {which is "Bitstream Vera Sans Mono"};
• - a Lua nil as a placeholder to not change this parameter but still allow a following one to be modified.

• onlyUseThisFont (optional) one of:

• - a Lua boolean true to require Mudlet to use graphemes (character) only from the selected font. Should a requested grapheme not be included in the selected font then the font replacement character (�) might be used instead; note that under some circumstances it is possible that the OS (or Mudlet) provided color Emoji Font may still be used but that cannot be guaranteed across all OS platforms that Mudlet might be run on;
• - a Lua boolean false to allow Mudlet to get a different glyph for a particular grapheme from the most suitable other font found in the system should there not be a glyph for it in the requested font. This is the default unless previously changed by this function or by the corresponding checkbox in the Profile Preferences dialogue for the profile concerned;
• - a Lua nil as a placeholder to not change this parameter but still allow the following one to be modified.

• scalingFactor (optional): a floating point value in the range 0.5 to 2.0 (default 1.0) that can be used to tweak the rectangular space that each different room symbol is scaled to fit inside; this might be useful should the range of characters used to make the room symbols be consistently under- or over-sized.

Returns

• true on success
• nil and an error message on failure. As the symbol font details are stored in the (binary) map file rather than the profile then this function will not work until a map is loaded (or initialised, by activating a map window).

Miscellaneous Functions

Miscellaneous functions.

deleteAllNamedEventHandlers

deleteAllNamedEventHandlers(handlerName)

Deletes all named event handlers and prevents them from firing any more. Information is deleted and cannot be retrieved.

See also

registerNamedEventHandler(), stopNamedEventHandler()

Available in Mudlet4.14+

Example

deleteAllNamedEventHandlers() -- emergency stop or debugging situation, most likely.

deleteNamedEventHandler

success = deleteNamedEventHandler(handlerName)

Deletes a named event handler with name handlerName and prevents it from firing any more. Information is deleted and cannot be retrieved.

See also

registerNamedEventHandler(), stopNamedEventHandler()

Available in Mudlet4.14+

Parameters

• handlerName:

The name of the handler to stop. Same as used when you called registerNamedEventHandler()

Returns

• true if successful, false if it didn't exist

Example

local deleted = deletedNamedEventHandler("DemonVitals")
if deleted then
  cecho("DemonVitals deleted forever!!")
else
  cecho("DemonVitals doesn't exist and so could not be deleted.")
end

getCharacterName

getCharacterName()

Returns the name entered into the "Character name" field on the Connection Preferences form. Can be used to find out the name that might need to be handled specially in scripts or anything that needs to be personalized to the player. If there is nothing set in that entry will return an empty string.

Introduced along with four other functions to enable game server log-in to be scripted with the simultaneous movement of that functionality from the Mudlet application core code to a predefined doLogin() function that may be replaced for more sophisticated requirements.

See also: sendCharacterName(), sendCharacterPassword(), sendCustomLoginText(), getCustomLoginTextId().

Note: Not available yet. See https://github.com/Mudlet/Mudlet/pull/3952

Example

lua send("cast 'glamor' " .. getCharacterName())

You get a warm feeling passing from your core to the tips of your hands, feet and other body parts.
A small twittering bird settles on your shoulder and starts to look adoringly at you.
A light brown faun gambles around you and then nuzzles your hand.
A tawny long-haired cat saunters over and start to rub itself against your ankles.
A small twittering bird settles on your shoulder and starts to look adoringly at you.
A light brown faun gambles around you and then nuzzles your hand.
A small twittering bird settles on your shoulder and starts to look adoringly at you.
A mangy dog trots up to you and proceeds to mark the bottom of your leggings.

getCustomLoginTextId

getCustomLoginTextId()

Returns the Id number of the custom login text setting from the profile's preferences. Returns 0 if the option is disabled or a number greater than that for the item in the table; note it is possible if using an old saved profile in the future that the number might be higher than expected. As a design policy decision it is not permitted for a script to change the setting, this function is intended to allow a script or package to check that the setting is what it expects.

Introduced along with four other functions to enable game server log-in to be scripted with the simultaneous movement of that functionality from the Mudlet application core code to a predefined doLogin() function, a replacement for which is shown below.

See also: getCharacterName(), sendCharacterName(), sendCustomLoginText(), sendPassword().

Note: Not available yet. See https://github.com/Mudlet/Mudlet/pull/3952

Only one custom login text has been defined initially:

Predefined custom login texts

Id	Custom text	Introduced in Mudlet version
1	"connect {character name} {password}"	TBD

The addition of further texts would be subject to negotiation with the Mudlet Makers.

Example

-- A replacement for the default function placed into LuaGlobal.lua to reproduce the previous behavior of the Mudlet application:
function doLogin()
  if getCustomLoginTextId() ~= 1 then
    -- We need this particular option but it is not permitted for a script to change the setting, it can only check what it is
    echo("\nUnable to login - please select the 'connect {character name} {password}` custom login option in the profile preferences.\n")
  else
    tempTime(2.0, [[sendCustomLoginText()]], 1)
  end
end

getNewIDManager

getNewIDManager()

Returns an IDManager object, for manager your own set of named events and timers isolated from the rest of the profile.

See also

registerNamedEventHandler(), registerNamedTimer()

Available in Mudlet4.14+

Returns

• an IDManager for managing your own named events and timers

Example

demonnic = demonnic or {}
demonnic.IDManager = getNewIDManager()
local idm = demonnic.IDManager
-- assumes you have defined demonnic.vitalsUpdate and demonnic.balanceChecker as functions
idm:registerEvent("DemonVitals", "gmcp.Char.Vitals", demonnic.vitalsUpdate)
idm:registerTimer("Balance Check", 1, demonnic.balanceChecker)
idm:stopEvent("DemonVitals")

getNamedEventHandlers

handlers = getNamedEventHandlers()

Returns a list of all the named event handlers' names as a table.

See also

registerNamedEventHandler()

Available in Mudlet4.14+

Returns

• a table of handler names. { "DemonVitals", "DemonInv" } for example. {} if none are registered

Example

  local handlers = getNamedEventHandlers()
  display(handlers)
  -- {}
  registerNamedEventHandler("Test1", "testEvent", "testFunction")
  registerNamedEventHandler("Test2", "someOtherEvent", myHandlerFunction)
  handlers = getNamedEventHandlers()
  display(handlers)
  -- { "Test1", "Test2" }

registerNamedEventHandler

success = registerNamedEventHandler(handlerName, eventName, functionReference, [oneShot])

Registers a named event handler with name handlerName. Named event handlers are protected from duplication and can be stopped and resumed, unlike anonymous event handlers.

See also

registerAnonymousEventHandler(), stopNamedEventHandler(), resumeNamedEventHandler(), deleteNamedEventHandler(), registerNamedTimer()

Available in Mudlet4.14+

Parameters

• handlerName:

The name of the handler. Used to reference the handler in other functions and prevent duplicates. Recommended you use descriptive names, "hp" is likely to collide with something else, "DemonVitals" less so.

• eventName:

The name of the event the handler responds to. See here for a list of Mudlet-raised events.

• functionReference:

The function reference to run when the event comes in. Can be the name of a function, "handlerFuncion", or the lua function itself.

• oneShot:

(optional) if true, the event handler will only fire once when the event is raised. If you need to extend a one shot event handler for "one more check" you can have the handler return true, and it will keep firing until the function does not return true.

Returns

• true if successful, otherwise errors.

Example

-- register a named event handler. Will call demonVitalsHandler(eventName, ...) when gmcp.Char.Vitals is raised.
local ok = registerNamedEventHandler("DemonVitals", "gmcp.Char.Vitals", "demonVitalsHandler")
if ok then
  cecho("Vitals handler switched to demonVitalsHandler")
end

-- something changes later, and we want to handle vitals with another function, demonBlackoutHandler()
-- note we do not use "" around demonBlackoutHandler but instead pass the function itself. Both work.
-- using the same handlerName ("DemonVitals") means it will automatically unregister the old handler
-- and reregister it using the new information.
local ok = registerNamedEventHandler("DemonVitals", "gmcp.Char.Vitals", demonBlackoutHandler)
if ok then
  cecho("Vitals handler switched to demonBlackoutHandler")
end

-- Now you want to check your inventory, but you only want to do it once, so you pass the optional oneShot as true
local function handleInv()
  local list = gmcp.Char.Items.List
  if list.location ~= "inventory" then
    return true -- if list.location is, say "room" then we need to keep responding until it's "inventory"
  end
  display(list.items) -- you would probably store values and update displays or something, but here I'll just show the data as it comes in
end

-- you can ignore the response from registerNamedEventHandler if you want, it's always going to be true
-- unless there is an error, in which case it throws the error and halts execution anyway. The return is
-- in part for feedback when using the lua alias or other REPL window.
registerNamedEventHandler("DemonInvCheck", "gmcp.Char.Items.List", handleInv, true)

resumeNamedEventHandler

success = resumeNamedEventHandler(handlerName)

Resumes a named event handler with name handlerName and causes it to start firing once more

See also

registerNamedEventHandler(), stopNamedEventHandler()

Available in Mudlet4.14+

Parameters

• handlerName:

The name of the handler to resume. Same as used when you called registerNamedEventHandler()

Returns

• true if successful, false if it didn't exist.

Example

local resumed = resumeNamedEventHandler("DemonVitals")
if resumed then
  cecho("DemonVitals resumed!")
else
  cecho("DemonVitals doesn't exist, cannot resume it")
end

sendCharacterName

sendCharacterName()

Sends the name entered into the "Character name" field on the Connection Preferences form directly to the game server. Returns true unless there is nothing set in that entry in which case a nil and an error message will be returned instead.

Introduced along with four other functions to enable game server log-in to be scripted with the simultaneous movement of that functionality from the Mudlet application core code to a predefined doLogin() function that may be replaced for more sophisticated requirements.

See also: getCharacterName(), sendCharacterPassword(), sendCustomLoginText(), getCustomLoginTextId().

Note: Not available yet. See https://github.com/Mudlet/Mudlet/pull/3952

sendCharacterPassword

sendCharacterPassword()

Sends the password entered into the "Password" field on the Connection Preferences form directly to the game server. Returns true unless there is nothing set in that entry or it is too long after (or before) a connection was successfully made in which case a nil and an error message will be returned instead.

Introduced along with four other functions to enable game server log-in to be scripted with the simultaneous movement of that functionality from the Mudlet application core code to a predefined doLogin() function, reproduced below, that may be replaced for more sophisticated requirements.

See also: getCharacterName(), sendCustomLoginText(), getCustomLoginTextId(), sendCharacterName().

Note: Not available yet. See https://github.com/Mudlet/Mudlet/pull/3952

Example

-- The default function placed into LuaGlobal.lua to reproduce the previous behavior of the Mudlet application:
function doLogin()
  if getCharacterName() ~= "" then
    tempTime(2.0, [[sendCharacterName()]], 1)
    tempTime(3.0, [[sendCharacterPassword()]], 1)
  end
end

sendCustomLoginText

sendCustomLoginText()

Sends the custom login text (which does NOT depend on the user's choice of GUI language) selected in the preferences for this profile. The {password} (and {character name} if present) fields will be replaced with the values entered into the "Password" and "Character name" fields on the Connection Preferences form and then sent directly to the game server. Returns true unless there is nothing set in either of those entries (though only if required for the character name) or it is too long after (or before) a connection was successfully made or if the custom login feature is disabled, in which case a nil and an error message will be returned instead.

Introduced along with four other functions to enable game server log-in to be scripted with the simultaneous movement of that functionality from the Mudlet application core code to a predefined doLogin() function, a replacement for which is shown below.

See also: getCharacterName(), sendCharacterName(), sendPassword(), getCustomLoginTextId().

Note: Not available yet. See https://github.com/Mudlet/Mudlet/pull/3952

Only one custom login text has been defined initially:

Predefined custom login texts

Id	Custom text	Introduced in Mudlet version
1	"connect {character name} {password}"	TBD

The addition of further texts would be subject to negotiation with the Mudlet Makers.

Example

-- A replacement for the default function placed into LuaGlobal.lua to reproduce the previous behavior of the Mudlet application:
function doLogin()
  if getCustomLoginTextId() ~= 1 then
    -- We need this particular option but it is not permitted for a script to change the setting, it can only check what it is
    echo("\nUnable to login - please select the 'connect {character name} {password}` custom login option in the profile preferences.\n")
  else
    tempTime(2.0, [[sendCustomLoginText()]], 1)
  end
end

stopAllNamedEventHandlers

stopAllNamedEventHandlers(handlerName)

Stops all named event handlers and prevents them from firing any more. Information is retained and handlers can be resumed.

See also

registerNamedEventHandler(), stopNamedEventHandler(), resumeNamedEventHandler()

Available in Mudlet4.14+

Example

stopAllNamedEventHandlers() -- emergency stop situation, most likely.

stopNamedEventHandler

success = stopNamedEventHandler(handlerName)

Stops a named event handler with name handlerName and prevents it from firing any more. Information is stored so it can be resumed later if desired.

See also

registerNamedEventHandler(), resumeNamedEventHandler()

Available in Mudlet4.14+

Parameters

• handlerName:

The name of the handler to stop. Same as used when you called registerNamedEventHandler()

Returns

• true if successful, false if it didn't exist or was already stopped

Example

local stopped = stopNamedEventHandler("DemonVitals")
if stopped then
  cecho("DemonVitals stopped!")
else
  cecho("DemonVitals doesn't exist or already stopped; either way it won't fire any more.")
end

Scripting Object Functions

A collection of functions that manipulate Mudlets scripting objects - triggers, aliases, and so forth.

deleteAllNamedTimers

deleteAllNamedTimers(handlerName)

Deletes all named timers and prevents them from firing any more. Information is deleted and cannot be retrieved.

See also

registerNamedTimer(), stopNamedTimer()

Available in Mudlet4.14+

Example

deleteAllNamedTimers() -- emergency stop or debugging situation, most likely.

deleteNamedTimer

success = deleteNamedTimer(handlerName)

Deletes a named timer with name handlerName and prevents it from firing any more. Information is deleted and cannot be retrieved.

See also

registerNamedTimer(), stopNamedTimer()

Available in Mudlet4.14+

Parameters

• handlerName:

The name of the handler to stop. Same as used when you called registerNamedTimer()

Returns

• true if successful, false if it didn't exist

Example

local deleted = deletedNamedTimer("DemonVitals")
if deleted then
  cecho("DemonVitals deleted forever!!")
else
  cecho("DemonVitals doesn't exist and so could not be deleted.")
end

getNamedTimers

timers = getNamedTimers()

Returns a list of all the named timers' names as a table.

See also

registerNamedTimer()

Available in Mudlet4.14+

Returns

• a table of handler names. { "DemonVitals", "DemonInv" } for example. {} if none are registered

Example

  local timers = getNamedTimers()
  display(timers)
  -- {}
  registerNamedTimer("Test1", "testEvent", "testFunction")
  registerNamedTimer("Test2", "someOtherEvent", myHandlerFunction)
  timers = getNamedTimers()
  display(timers)
  -- { "Test1", "Test2" }

registerNamedTimer

success = registerNamedTimer(handlerName, eventName, functionReference, [repeating])

Registers a named timer with name handlerName. Named timers are protected from duplication and can be stopped and resumed, unlike normal tempTimers.

See also

tempTimer(), stopNamedTimer(), resumeNamedTimer(), deleteNamedTimer(), registerNamedEventHandler()

Available in Mudlet4.14+

Parameters

• handlerName:

The name of the handler. Used to reference the handler in other functions and prevent duplicates. Recommended you use descriptive names, "hp" is likely to collide with something else, "DemonVitals" less so.

• eventName:

The name of the event the handler responds to. See here for a list of Mudlet-raised events.

• functionReference:

The function reference to run when the event comes in. Can be the name of a function, "handlerFuncion", or the lua function itself.

• repeating:

(optional) if true, the timer continue to fire until the stop it using stopNamedTimer()

Returns

• true if successful, otherwise errors.

Example

-- establish a named timer called "Check balance" which runs balanceChecker() after 1 second
-- it is started automatically when registered, and fires only once despite being run twice
-- you wouldn't do this intentionally, but illustrates the duplicate protection
registerNamedTimer("Check Balance", 1, balanceChecker)
registerNamedTimer("Check Balance", 1, balanceChecker)

-- then the next time you want to make/use the same timer, you can shortcut it with
resumeNamedTimer("Check Balance")

resumeNamedTimer

success = resumeNamedTimer(handlerName)

Resumes a named timer with name handlerName and causes it to fire again. One time unless it was registered as repeating.

See also

registerNamedTimer(), stopNamedTimer()

Available in Mudlet4.14+

Parameters

• handlerName:

The name of the handler to resume. Same as used when you called registerNamedTimer()

Returns

• true if successful, false if it didn't exist. If the timer is waiting to fire it will be restarted at 0.

Example

local resumed = resumeNamedTimer("DemonVitals")
if resumed then
  cecho("DemonVitals resumed!")
else
  cecho("DemonVitals doesn't exist, so cannot resume it.")
end

stopAllNamedTimers

stopAllNamedTimers(handlerName)

Stops all named timers and prevents them from firing any more. Information is retained and timers can be resumed.

See also

registerNamedTimer(), stopNamedTimer(), resumeNamedTimer()

Available in Mudlet4.14+

Example

stopAllNamedTimers() -- emergency stop situation, most likely.

stopNamedTimer

success = stopNamedTimer(handlerName)

Stops a named timer with name handlerName and prevents it from firing any more. Information is stored so it can be resumed later if desired.

See also

registerNamedTimer(), resumeNamedTimer()

Available in Mudlet4.14+

Parameters

• handlerName:

The name of the handler to stop. Same as used when you called registerNamedTimer()

Returns

• true if successful, false if it didn't exist or was already stopped

Example

local stopped = stopNamedTimer("DemonVitals")
if stopped then
  cecho("DemonVitals stopped!")
else
  cecho("DemonVitals doesn't exist or already stopped; either way it won't fire any more.")
end

Networking Functions

A collection of functions for managing networking.

String Functions

These functions are used to manipulate strings.

Table Functions

These functions are used to manipulate tables. Through them you can add to tables, remove values, check if a value is present in the table, check the size of a table, and more.

Text to Speech Functions

These functions are used to create sound from written words. Check out our Text-To-Speech Manual for more detail on how this all works together.

UI Functions

These functions are used to construct custom user GUIs. They deal mainly with miniconsole/label/gauge creation and manipulation as well as displaying or formatting information on the screen.