Module:Protect

這個模板被使用在系統訊息中。
對此模板的修改會立即反映在維基百科用戶介面上，為避免造成大規模的影響，任何編輯應該先在此模板的沙盒頁面、測試樣例或您自己的用戶子頁面中測試，測試過後的修改才能在單次編輯中添加到此模板。請在做任何修改之前在此討論頁中進行討論。

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 transformed.
errFormat (default: 'Error: %s')
Custom error message.

Use '%s' to include the message from a caught error.
options – optional table with the following fields:
- raw (default: false)
  If true, then errFormat will be used as is, otherwise it will be wrapped inside a tag <strong class="error">.
- removeLocation (default: true)
  If true, removes location information from caught error messages.

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

上述文档嵌入自Module:Protect/doc。 (编辑 | 历史)
编者可以在本模块的沙盒 (创建 | 镜像)和测试样例 (创建)页面进行实验。
本模块的子页面。

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