Module:Template wrapper

require('Module:No globals');

local error_msg = '|_template= 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

--[[--------------------------< 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 '_include-positional' ~= 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 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 _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

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 = frame:getParent(); -- here we get the wrapper template's 'live' parameters from pframe.args 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 Template:Cite compare and Template:Cite compare2

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

]]

local function list (frame) 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

return frame:preprocess (table.concat ({'{{', template, ' |', table.concat( args, ' |' ), '}}'})); -- render the template end

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

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