Module:Template wrapper

require('strict');

local error_msg = ' missing or empty ';

--[[--< I S _ I N _ T A B L E >

scan through tbl looking for value; return true if found, false else

]]

local function is_in_table (tbl, value) for k, v in pairs (tbl) do       if v == value then return true end end return false; end

--[[--< A D D _ P A R A M E T E R >

adds parameter name and its value to args table according to the state of boolean list argument; kv pair for template execution; k=v string for template listing.

]]

local function add_parameter (k, v, args, list) if list then table.insert( args, table.concat ({k, '=', v}));						-- write parameter names and values to args table as string else args[k] = v;															-- copy parameters to args table end end

--[[--< A L I A S _ M A P _ G E T >

returns a table of local template (parent frame) parameter names and the target template names that match where in [key]= pairs where: [key] is local template parameter name (an alias) is target template parameter name (the canonical parameter name used in the working template)

The parameter |_alias-map= has the form: |_alias-map= where is a comma-separated list of alias / canonical parameter name pairs in the form :  where: is the local template's parameter name (alias)  is the target template's parameter name (canonical) for enumerated parameters place an octothorp (#) where the enumerator digits are placed in the parameter names:  : 

]]

local function alias_map_get (_alias_map) local T = mw.text.split (_alias_map, '%s*,%s*');							-- convert the comma-separated list into a table of alias pairs local mapped_aliases = {};													-- mapped aliases will go here local l_name, t_name;														-- parameter names for _, alias_pair in ipairs (T) do											-- loop through the table of alias pairs l_name, t_name = alias_pair:match ('(.-)%s*:%s*(.+)');					-- from each pair, get local and target parameter names if l_name and t_name then												-- if both are set if tonumber (l_name) then l_name = tonumber (l_name);										-- convert number-as-text to a number end mapped_aliases[l_name] = t_name;									-- add them to the map table end end

return mapped_aliases; end

--[[--< F R A M E _ A R G S _ G E T >--

Fetch the wrapper template's 'default' and control parameters; adds default parameters to args

returns content of |_template= parameter (name of the working template); nil else

]]

local function frame_args_get (frame_args, args, list) local template;

for k, v in pairs (frame_args) do											-- here we get the wrapper template's 'default' parameters if 'string' == type (k) and (v and ('' ~= v)) then						-- do not pass along positional or empty parameters if '_template' == k then template = v;													-- save the name of template that we are wrapping elseif '_exclude' ~= k and '_reuse' ~= k and '_include-positional' ~= k and '_alias-map' ~= k then	-- these already handled so ignore here; add_parameter (k, v, args, list);								-- add all other parameters to args in the style dictated by list end end end

return template;															-- return contents of |_template= parameter end

--[=[--< P F R A M E _ A R G S _ G E T >

Fetches the wrapper template's 'live' parameters; adds live parameters that aren't members of the exclude table to args table; positional parameters may not be excluded

no return value

]=]

local function pframe_args_get (pframe_args, args, exclude, _include_positional, list) for k, v in pairs (pframe_args) do		if 'string' == type (k) and not is_in_table (exclude, k) then			-- do not pass along excluded parameters if v and ('' ~= v) then												-- pass along only those parameters that have assigned values if 'unset' == v:lower then									-- special keyword to unset 'default' parameters set in the wrapper template v = '';														-- unset the value in the args table end add_parameter (k, v, args, list)								-- add all other parameters to args in the style dictated by list; alias map only supported for local-template parameters end end end

if _include_positional then for i, v in ipairs (pframe_args) do										-- pass along positional parameters if 'unset' == v:lower then										-- special keyword to unset 'default' parameters set in the wrapper template v = '';															-- unset the value in the args table end add_parameter (i, v, args, list); end end end

--[[--< _ M A I N >

Collect the various default and live parameters into args styled according to boolean list.

returns name of the working or listed template or nil for an error message

]]

local function _main (frame, args, list) local template; local exclude = {};															-- table of parameter names for parameters that are not passed to the working template local reuse_list = {};														-- table of pframe parameter names whose values are modified before they are passed to the working template as the same name local alias_map = {};														-- table that maps parameter aliases to working template canonical parameter names local _include_positional; if frame.args._exclude and ('' ~= frame.args._exclude) then					-- if there is |_exclude= and it's not empty exclude = mw.text.split (frame.args._exclude, "%s*,%s*");				-- make a table from its contents end -- TODO: |_reuse= needs a better name (|_reuse=) if frame.args._reuse and ('' ~= frame.args._reuse) then					-- if there is |_reuse= and it's not empty reuse_list = mw.text.split (frame.args._reuse, "%s*,%s*");				-- make a table from its contents end

if frame.args['_alias-map'] and ('' ~= frame.args['_alias-map']) then		-- if there is |_alias-map= and it's not empty alias_map = alias_map_get (frame.args['_alias-map']);					-- make a table from its contents end

template = frame_args_get (frame.args, args, list);							-- get parameters provided in the if nil == template or '' == template then									-- this is the one parameter that is required by this module return nil;																-- not present, tell calling function to emit an error message end _include_positional = 'yes' == frame.args['_include-positional'];			-- when true pass all positional parameters along with non-excluded named parameters to ... -- ... the working template; positional parameters are not excludable local _pframe_args = frame:getParent.args;								-- here we get the wrapper template's 'live' parameters from pframe.args local pframe_args = {};														-- a local table that we can modify

for k, v in pairs (_pframe_args) do											-- make a copy that we can modify pframe_args[k] = v;	end -- here we look for pframe parameters that are aliases of canonical parameter names; when found -- we replace the alias with the canonical. We do this here because the reuse_list works on -- canonical parameter names so first we convert alias parameter names to canonical names and then -- we remove those canonical names from the pframe table that are reused (provided to the working -- template through the frame args table)

for k, v in pairs (alias_map) do											-- k is alias name, v is canonical name if pframe_args[k] then													-- if pframe_args has parameter with alias name pframe_args[v] = _pframe_args[k];									-- create new canonical name with alias' value pframe_args[k] = nil;												-- unset the alias end end

for k, v in pairs (pframe_args) do											-- do enumerated parameter alias -> canonical translation if 'string' == type (k) then											-- only named parameters can be enumerated if alias_map[k..'#'] then											-- non-enumerated alias matches enumerated parameter pattern? enumerator at end only pframe_args[alias_map[k..'#']:gsub('#', '')] = v;				-- remove '#' and copy parameter to pframe_args table pframe_args[k] = nil;											-- unset the alias elseif k:match ('%d+') then											-- if this parameter name contains digits local temp = k:gsub ('%d+', '#');								-- make a copy; digits replaced with single '#' local enum = k:match ('%d+');									-- get the enumerator if alias_map[temp] then											-- if this parameter is a recognized enumerated alias pframe_args[alias_map[temp]:gsub('#', enum)] = v;			-- use canonical name and replace '#' with enumerator and add to pframe_args pframe_args[k] = nil;										-- unset the alias end end end end

-- pframe parameters that are _reused are 'reused' have the form something like this: --	|chapter= -- where a parameter in the wrapping template is modified and then passed to the working template -- using the same parameter name (in this example |chapter=)

-- remove parameters that will be reused for k, v in ipairs (reuse_list) do											-- k is numerical index, v is canonical parameter name to ignore if pframe_args[v] then													-- if pframe_args has parameter that should be ignored pframe_args[v] = nil;												-- unset the ignored parameter end end

pframe_args_get (pframe_args, args, exclude, _include_positional, list);	-- add parameters and values to args that are not listed in the exclude table

return template;															-- args now has all default and live parameters, return working template name end

--[[--< W R A P >--

Template entry point. Call this function to 'execute' the working template

]]

local function wrap (frame) local args = {};															-- table of default and live parameters and their values to be passed to the wrapped template local template;																-- the name of the working template

template = _main (frame, args, false);										-- get default and live parameters and the name of the working template if not template then														-- template name is required return error_msg;														-- emit error message and abandon if template name not present end

return frame:expandTemplate {title=template, args=args};					-- render the working template end

--[[--< L I S T >--

Template entry point. Call this function to 'display' the source for the working template. This function added as a result of a TfD here: Wikipedia:Templates_for_discussion/Log/2018_April_28#Module:PassArguments

This function replaces a similarly named function which was used in and

Values in the args table are numerically indexed strings in the form 'name=value'

]]

local function list(frame, do_link) local args = {};						-- table of default and live parameters and their values to be passed to the listed template local template;							-- the name of the listed template

template = _main (frame, args, true);	-- get default and live parameters and the name of the listed template if not template then					-- template name is required return error_msg;					-- emit error message and abandon if template name not present end if do_link then template = ('%s'):format(frame:expandTemplate{ title='Transclude', args = {template} }, template) end table.sort(args) for i = 1, #args do local stripped = args[i]:match('^' .. i .. '=([^=]*)$') if stripped then args[i] = stripped else break end end return frame:preprocess(table.concat({ ' '}));	-- render the template end

local function link (frame) return list(frame, true) end

----< E X P O R T E D  F U N C T I O N S >--

return { link = link, list = list, wrap = wrap, };