Module:Protect
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Module documentation | This module is rated as ready for general use. It has reached a mature form and is thought to be bug-free and ready for use wherever appropriate. It is ready to mention on help pages and other WikiDevi resources as an option for new users to learn. To reduce server load and bad output, it should be improved by sandbox testing rather than repeated trial-and-error editing. |
 | This module is used in system messages. Changes to it can cause immediate changes to the WikiDevi user interface. To avoid large-scale disruption, any changes should first be tested in this module's /sandbox or /testcases subpage, or in your own user space. The tested changes can then be added in one single edit to this module. Please discuss any changes on the talk page before implementing them. |
This metamodule simplifies error handling in other modules. It transforms a function, which may throw an error, into a function, which returns a specified error message in that case.
Usage
local protect = require('Module:Protect')
local protectedFunc = protect(func, errFormat, options)
Arguments
func– Function to be transformederrFormat– Custom error message (default:'Error: %s'), use'%s'to include the message from a caught error.options– optional table with the following fields:raw– If true, thenerrFormatwill be used as is, otherwise it will be wrapped inside a tag<strong class="error">…</strong>(default: false)removeLocation– If true, removes location information from caught error messages (default: true)
Return value
The resulting protectedFunc is a function, which calls the original function func, passing all arguments to it, and returns all its return values. If func throws an error, the specified error message is returned instead.
Example
local protect = require('Module:Protect')
local p = {}
function p.main(frame)
if not frame.args[1] then
error('missing argument')
end
return frame.args[1]
end
p.main = protect(p.main)
return p
Invoking the main function without arguments will output: Error: missing argument
| The above documentation is transcluded from Module:Protect/doc. (edit | history) Editors can experiment in this module's sandbox (create | mirror) and testcases (create) pages. Subpages of this module. |
local function processResult(options, success, ...)
if not success then
local message = tostring(... or '(no message)')
if options.removeLocation then
message = string.gsub(message, '^Module:[^:]+:%d+: ', '', 1)
end
return string.format(options.errFormat, message)
end
return ...
end
local function protect(func, errFormat, options)
if type(errFormat) == 'table' then
options = options or errFormat
errFormat = nil
end
options = mw.clone(options) or {}
options.errFormat = errFormat or options.errFormat or 'Error: %s'
if not options.raw then
options.errFormat = '<strong class="error">' .. options.errFormat .. '</strong>'
end
options.removeLocation = options.removeLocation == nil or options.removeLocation
return function (...)
return processResult(options, pcall(func, ...))
end
end
return protect
