Module:No globals/sandbox: Difference between revisions
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Latest revision as of 07:21, 20 July 2022
 | This is the module sandbox page for Module:No globals (diff). See also the companion subpage for test cases (run). |
Module documentation | This Lua module is used in system messages, and on approximately 18,200,000 pages, or roughly 74261% 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
- Scribunto's Strict library – A library like No globals built into the Scribunto extension
local mt = getmetatable(_G) or {}
function mt.__index (t, k)
if k ~= 'arg' then
-- perf optimization here and below: do not load Module:TNT unless there is an error
error(require('Module:TNT').format('I18n/No globals', 'err-read', tostring(k)), 2)
end
return nil
end
function mt.__newindex(t, k, v)
if k ~= 'arg' then
error(require('Module:TNT').format('I18n/No globals', 'err-write', tostring(k)), 2)
end
rawset(t, k, v)
end
setmetatable(_G, mt)
