Module:Error

This Lua module is used on approximately ༤༧,༠༠༠ pages and changes may be widely noticed. Test changes in the module's /sandbox or /testcases subpages, or in your own module sandbox. Consider discussing 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 implements {{Error}}. It creates an html message with class "error". Please, see the documentation page there for usage instructions.

-- This module implements {{error}}.

local p = {}

local function _error(args)
    local tag = mw.ustring.lower(tostring(args.tag))

    -- Work out what html tag we should use.
    if not (tag == 'p' or tag == 'span' or tag == 'div') then
        tag = 'strong'
    end

    -- Generate the html.
    return tostring(mw.html.create(tag)
        :addClass('error')
        :wikitext(tostring(args.message or args[1] or error('no message specified', 2)))
    )
end

function p.error(frame)
    local args
    if type(frame.args) == 'table' then
        -- We're being called via #invoke. The args are passed through to the module
        -- from the template page, so use the args that were passed into the template.
        args = frame.args
    else
        -- We're being called from another module or from the debug console, so assume
        -- the args are passed in directly.
        args = frame
    end
    -- if the message parameter is present but blank, change it to nil so that Lua will
    -- consider it false.
    if args.message == "" then
        args.message = nil
    end
    return _error(args)
end

return p

See also