Module:If empty: Difference between revisions

    From Consumerium development wiki R&D Wiki
    (actually, only the first 8 need this check)
    (No difference)

    Revision as of 21:56, 23 December 2014

    Documentation for this module may be created at Module:If empty/doc

    local p = {}
    
    function p.main(frame)
    	local args = require('Module:Arguments').getArgs(frame, {wrappers = 'Template:If empty', removeBlanks = false})
    
    	-- For backwards compatibility reasons, the first 8 parameters can be unset instead of being blank,
    	-- even though there's really no legitimate use case for this. At some point, this will be removed.
    	local lowestNil = math.huge
    	for i = 8,1,-1 do
    		if args[i] == nil then
    			args[i] = ''
    			lowestNil = i
    		end
    	end
    
    	for k,v in ipairs(args) do
    		if v ~= '' then
    			if lowestNil < k then
    				-- If any uses of this template depend on the behavior above, add them to a tracking category.
    				-- This is a rather fragile, convoluted, hacky way to do it, but it ensures that this module's output won't be modified
    				-- by it.
    				frame:extensionTag('ref', '[[Category:Instances of Template:If_empty missing arguments]]', {group = 'TrackingCategory'})
    				frame:extensionTag('references', '', {group = 'TrackingCategory'})
    			end
    			return v
    		end
    	end
    end
    
    return p