Module:Bad title suggestion

This module implements title suggestions for the "Bad title" interface message at MediaWiki:Title-invalid-characters. When the user asks for a page with invalid characters, this module checks for a page with the given title up to the first invalid character. If it exists, {{Did you mean box}} is displayed.

Usage

{{#invoke:Bad title suggestion|main|invalid_char|bad_title_encoded}}

In the case of MediaWiki:Title-invalid-characters, this is:

{{#invoke:Bad title suggestion|main|$1|$2}}

Examples

• Foobar>: {{#invoke:Bad title suggestion|main|>|Foobar>}}

• Wikipedia:Village pump}}: {{#invoke:Bad title suggestion|main|}|Wikipedia:Village pump}}}}

• Main Page|title text!: {{#invoke:Bad title suggestion|main|||Main Page|title text!}}

• This page absolutely does not exist>: {{#invoke:Bad title suggestion|main|>|This page absolutely does not exist>}}

(nothing displayed)

• Category:Contents>: {{#invoke:Bad title suggestion|main|>|Category:Contents>}}

• <Foobar>: {{#invoke:Bad title suggestion|main|<|#60;Foobar#62;}}

(nothing displayed)

---

local getArgs = require("Module:Arguments").getArgs
local p = {}

function p.main(frame)
	local args = getArgs(frame)
	-- The invalid character, e.g. ">" or "}"
	local chr = args[1]
	-- The escaped bad title, e.g. "Foobar>" or "Foobar|text"
	local title = args[2]
	-- A pipe (|) as the invalid character is a special case; it is not
	-- escaped, so instead the module thinks it got two empty arguments
	-- and the title as the third argument.
	if chr == nil and title == nil then
		chr = "|"
		title = args[3]
	end
	if chr == nil or title == nil then
		return ""
	end

	-- Determine the suggested title by taking a prefix of the bad title
	-- up to the first invalid character. Only display the suggestion box
	-- if the page exists.
	local index = mw.ustring.find(title, mw.text.nowiki(chr), 1, true)
	if index == nil then
		return ""
	end
	local page = mw.title.new(mw.ustring.sub(title, 1, index - 1))
	if page == nil or not page.exists then
		return ""
	end
	return frame:expandTemplate{
		title = "Did you mean box",
		args = { page.fullText }
	}
end

return p