Module:Delink

This module implements the {{delink}} template. Please see the template page for documentation.

---

-- 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, we check whether or not there are colons in the link, and trim it accordingly.
    if mw.ustring.match(s, ":") then
        -- If the link contains a colon, it could be a category or an interwiki,
        -- or it could use the [[Help:Colon trick]].
        
        -- Check for categories and interwikis.
        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$") then
            s = ""
            
        -- Check for the colon trick.
        elseif mw.ustring.match(s, "%[%[:") then
            s = mw.ustring.match(s, "%[%[:.-:(.*)|%]%]")
        
        -- Otherwise, remove the text before the first colon.
        else
            s = mw.ustring.match(s, "%[%[.-:(.*)|%]%]")
        end
    
    -- 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(text)
    if mw.ustring.match(text, "[^|].*|%]%]") or mw.ustring.match(text, "%[%[|") then -- Weed out the pipe tricks first.
        return delinkPipeTrick(text)
    end
    -- Find the link area and display area of the wikilink
    local linkarea, display
    if mw.ustring.match(text, "|") then -- Find if we're dealing with a piped link.
        linkarea, display = mw.ustring.match(text, "^%[%[(.-)|(.+)%]%]")
    else
        -- If the link isn't piped, the display area and the link area are the same.
        linkarea = mw.ustring.match(text, "^%[%[(.-)%]%]")
        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