Module:No globals
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This Lua module is used in system messages, and on approximately 17,800,000 pages, or roughly 185823% of all pages. Changes to it can cause immediate changes to the Wikipedia user interface. To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Please discuss changes on the talk page before implementing them. |
This module is subject to page protection. It is a highly visible module in use by a very large number of pages, or is substituted very frequently. Because vandalism or mistakes would affect many pages, and even trivial editing might cause substantial load on the servers, it is protected from editing. |
This module causes an error if any nil global is read or if any global is written to, with the exception of arg. To use, add require('Module:No globals')
to the top of the module using it. The arg variable is excluded because it is necessary for Scribunto's require function to work properly. (See the Scribunto source code here.)
See also
- Module:Log globals – adds all nil global reads/writes to the lua log
This module (and the documentation) are based (partially) on Module:No globals from the free encyclopedia wikipedia and is licensed under GNU license for free documentation and the Creative Commons Attribution/Share Alike. On wikipedia there is a List of authors accessible. More about importing from wikipedia on page Imedwiki:Importing from wikipedia.
local mt = getmetatable(_G) or {}
function mt.__index (t, k)
if k ~= 'arg' then
error('Tried to read nil global ' .. tostring(k), 2)
end
return nil
end
function mt.__newindex(t, k, v)
if k ~= 'arg' then
error('Tried to write global ' .. tostring(k), 2)
end
rawset(t, k, v)
end
setmetatable(_G, mt)