SetTableProtected

From Multi Theft Auto: Wiki

This function sets a table protected from editing, so if you want to define constants that cannot be changed, this would be a way. I found that function from Internet, by Nick Gammon.

Syntax

table setTableProtected( table tbl )

Required Arguments

• tbl: The table, which is to be set protected

Returns

Returns the table which can't be modified anymore

Code

function setTableProtected (tbl)
  return setmetatable ({}, 
    {
    __index = tbl,  -- read access gets original table item
    __newindex = function (t, n, v)
       error ("attempting to change constant " .. 
             tostring (n) .. " to " .. tostring (v), 2)
      end -- __newindex, error protects from editing
    })
end

Example

my_constants =
  {
  WIDTH = 22,
  HEIGHT = 44,
  FOO = "bar",
  }
 
-- protect my table now
my_constants = setTableProtected (my_constants) -- it's important to redeclare that variable what you want to protect, since you could still modify the original table.
my_constants.WIDTH = 11
my_constants.HEIGHT = 11
-- These will return errors, because _newindex always returns error for that table
-- test it
print ("WIDTH",  my_constants.WIDTH)  --> WIDTH 22 -- and these remain unchanged
print ("HEIGHT", my_constants.HEIGHT) --> HEIGHT 44

Author: Nick Gammon, commented a bit and found from Internets - Lordy

See Also

• callClientFunction » This function allows you to call any clientside function from the server's side.

• callServerFunction » This function allows you to call any server-side function from the client's side.

• Check » This function checks if it's arguments are of the right types and calls the error-function if one isn't.

• doForAllElements » This function can be used to execute a specified function for all elements of a specified type.

• iterElements » Returns an iterator for your for loops saving time typing ipairs( getElementsByType( type ) ), instead you type: iterElements( type ).

• findRotation » Takes two points and returns the direction from point A to point B.

• FormatDate » Formats a date on the basis of a format string and returns it.

• getAge » This function calculates the age of a birthday.

• getPointFromDistanceRotation » Finds a point based on a starting point, direction and distance.

• getTimestamp » With this function you can get the UNIX timestamp.

• IfElse » Returns one of two values based on a boolean expression.

• isLeapYear » Checks if the given year is a leap year.

• math.round » Rounds a number whereas the number of decimals to keep and the method may be set.

• setTableProtected » Protects a table and makes it read-only.

• setVehicleGravityPoint » This clientside function sets a vehicle's gravity in the direction of a 3 dimensional coordinate with the strength specified.

• string.explode » This function splits a string at a given separator pattern and returns a table with the pieces.

• table.copy » This function copies a whole table and all the tables in that table.

• table.map » This function goes through a table and replaces every field with the return of the passed function, where the field's value is passed as first argument and optionally more arguments.

• table.size » Finds the absolute size of a table.

• var_dump »This function outputs information about one or more variables using outputConsole().

• RGBToHex » This function returns a string representing the color in hexadecimal.

• getAlivePlayersInTeam » This function returns a table of the alive players in a team.

• getResourceSettings » This function returns a table of the resource settings.

• onVehicleWeaponFire » This code implements an event that is triggered when a player in a vehicle fires a vehicles weapon.

• toHex » This function converts a decimal number to a hexadecimal number, as a fix to be used clientside.

• getElementSpeed » This function allows you to get element speed in kph or mph units.

• setElementSpeed » This function allows you to set moving element speed in kph or mph units.

• centerWindow » This function center the window in any resolution.

• coroutine.resume » Fix for hidden coroutine error messages

• getPlayerFromNamePart » This function allows you to get player From his Name part.