Difference between revisions of "Module:Delink"

Revision as of 12:35, 3 April 2013

-- This module de-links one internal wikilink. It doesn't handle bad links, or links that use the pipe trick.

p = {}

local function delinkPipeTrick(s)
    local linkarea, display = "", ""
    
    -- Deal with the left-hand pipe trick, an easy case.
    if mw.ustring.match(s, "%[%[|") then
        return mw.ustring.match(s, "%[%[|(.*)%]%]")
    end
    
    -- If the link isn't a left-hand pipe trick, assume it's a right-hand pipe trick.
    -- We need to deal with colons, brackets, and commas, per [[Help:Pipe trick]].
    
    -- First, remove the text before the first colon, if any.
    if mw.ustring.match(s, ":") then
        s = mw.ustring.match(s, "%[%[.-:(.*)|%]%]")
    -- If there are no colons, grab all of the text apart from the square brackets and the pipe.
    else
        s = mw.ustring.match(s, "%[%[(.*)|%]%]")
    end
    
    -- Next up, brackets and commas.
    if mw.ustring.match(s, "%(.-%)$") then -- Brackets trump commas.
        s = mw.ustring.match(s, "(.-) ?%(.-%)$")
    elseif mw.ustring.match(s, ",") then -- If there are no brackets, display only the text before the first comma.
        s = mw.ustring.match(s, "(.-),.*$")
    end
    return s
end

local function delinkOne(s)
    -- First, check for categories, interwikis, and files.
    local colonprefix = mw.ustring.match(s, "%[%[(.-):.*%]%]") or "" -- Get the text before the first colon.
    if mw.language.isKnownLanguageTag(colonprefix)
    or mw.ustring.match(colonprefix, "^[Cc]ategory$")
    or mw.ustring.match(colonprefix, "^[Ff]ile$")
    or mw.ustring.match(colonprefix, "^[Ii]mage$") then
        return ""
    end
    
    -- Remove the colon if the link is using the [[Help:Colon trick]].
    if mw.ustring.match(s, "%[%[:") then
        s = "[[" .. mw.ustring.match(s, "%[%[:(.*%]%])")
    end
    
    if mw.ustring.match(s, "[^|].*|%]%]") or mw.ustring.match(s, "%[%[|") then -- Weed out the pipe tricks first.
        return delinkPipeTrick(s)
    end
    -- Find the link area and display area of the wikilink
    local linkarea, display
    if mw.ustring.match(s, "|") then -- Find if we're dealing with a piped link.
        linkarea, display = mw.ustring.match(s, "^%[%[(.-)|(.+)%]%]")
    else
        -- If the link isn't piped, the display area and the link area are the same.
        linkarea = mw.ustring.match(s, "^%[%[(.-)%]%]")
        display = linkarea
    end
    -- Check for bad links
    if mw.ustring.match(linkarea, "%[") or mw.ustring.match(linkarea, "%]") then
        error("Bad link detected. Bad links are not yet supported.")
    end
    return display
end

local function _delink(args)
    local text = args[1] or ""
    text = mw.ustring.gsub(text, "%[%[.-%]%]", delinkOne)
    return text
end

function p.delink(frame)
    local args
    if frame == mw.getCurrentFrame() then
        -- We're being called via #invoke. If the invoking template passed any args, use
        -- them. Otherwise, use the args that were passed into the template.
        args = frame:getParent().args
        for k, v in pairs(frame.args) do
            args = frame.args
            break
        end
    else
        -- We're being called from another module or from the debug console, so assume
        -- the args are passed in directly.
        args = frame
    end
 
    return _delink(args)
end

return p