Module:Template invocation

This is a meta-module for producing MediaWiki template invocations.

Usage

First load the module:

local mTemplateInvocation = require('Module:Template invocation')

Then you can use the individual functions as documented below.

Name

mTemplateInvocation.name(title)

This function produces the name to be used in a template invocation. For pages in the template namespace it returns the page name with no namespace prefix, for pages in the main namespace it returns the full page name prefixed with ":", and for other pages it returns the full page name. title can be a string or a mw.title object.

Invocation

mTemplateInvocation.invocation(name, args, format)

This function creates a MediaWiki template invocation.

Parameters:

• name - the name of the template (string, required). This should be exactly as it will appear in the invocation, e.g. for Template:Example use "Example". To generate the template name from a page name you can use the name function.
• args - the arguments to use in the invocation (table, required). Table keys and values must be either strings or numbers.
• format - the format of the invocation (string, optional). The default is a normal invocation with unescaped curly braces, pipes, and equals signs. If this parameter is the string "nowiki", then the curly braces, pipes and equals signs are replaced with the appropriate HTML entities.

Example

The code mTemplateInvocation.invocation('foo', {'bar', 'baz', abc = 'def'}) would produce {{foo|bar|baz|abc=def}}.

---

-- This module provides functions for making MediaWiki template invocations.

local checkType = require('libraryUtil').checkType

local p = {}

------------------------------------------------------------------------
--         Name:  p.name
--      Purpose:  Find a template invocation name from a page name or a
--                mw.title object.
--  Description:  This function detects whether a string or a mw.title
--                object has been passed in, and uses that to find a
--                template name as it is used in template invocations.
--   Parameters:  title - full page name or mw.title object for the
--                template (string or mw.title object)
--      Returns:  String
------------------------------------------------------------------------

function p.name(title)
	if type(title) == 'string' then
		title = mw.title.new(title)
		if not title then
			error("invalid title in parameter #1 of function 'name'", 2)
		end
	elseif type(title) ~= 'table' or type(title.getContent) ~= 'function' then
		error("parameter #1 of function 'name' must be a string or a mw.title object", 2)
	end
	if title.namespace == 10 then
		return title.text
	elseif title.namespace == 0 then
		return ':' .. title.prefixedText
	else
		return title.prefixedText
	end
end

------------------------------------------------------------------------
--         Name:  p.invocation
--      Purpose:  Construct a MediaWiki template invocation.
--  Description:  This function makes a template invocation from the
--                name and the arguments given. Note that it isn't
--                perfect: we have no way of knowing what whitespace was
--                in the original invocation, the named parameters will be
--                alphabetically sorted, and any parameters with duplicate keys
--                will be removed.
--   Parameters:  name - the template name, formatted as it will appear
--                    in the invocation. (string)
--                args - a table of template arguments. (table)
--                format - formatting options. (string, optional)
--                    Set to "nowiki" to escape, curly braces, pipes and
--                    equals signs with their HTML entities. The default
--                    is unescaped.
--      Returns:  String
------------------------------------------------------------------------

function p.invocation(name, args, format)
	checkType('invocation', 1, name, 'string')
	checkType('invocation', 2, args, 'table')
	checkType('invocation', 3, format, 'string', true)

	-- Validate the args table and make a copy to work from. We need to
	-- make a copy of the table rather than just using the original, as
	-- some of the values may be erased when building the invocation.
	local invArgs = {}
	for k, v in pairs(args) do
		local typek = type(k)
		local typev = type(v)
		if typek ~= 'string' and typek ~= 'number'
			or typev ~= 'string' and typev ~= 'number'
		then
			error("invalid arguments table in parameter #2 of " ..
			"'invocation' (keys and values must be strings or numbers)", 2)
		end
		invArgs[k] = v
	end

	-- Get the separators to use.
	local seps = {
		openb = '{{',
		closeb = '}}',
		pipe = '|',
		equals = '='
	}
	if format == 'nowiki' then
		for k, v in pairs(seps) do
			seps[k] = mw.text.nowiki(v)
		end
	end

	-- Build the invocation body with numbered args first, then named.
	local ret = {}
	ret[#ret + 1] = seps.openb
	ret[#ret + 1] = name
	for k, v in ipairs(invArgs) do
		if type(v) == 'string' and v:find('=', 1, true) then
			-- Likely something like 1=foo=bar which needs to be displayed as a named arg.
		else
			ret[#ret + 1] = seps.pipe
			ret[#ret + 1] = v
			invArgs[k] = nil -- Erase the key so that we don't add the value twice
		end
	end
	local keys = {} -- sort parameter list; better than arbitrary order
	for k, _ in pairs(invArgs) do
		keys[#keys + 1] = k
	end
	table.sort(keys, function (a, b)
			-- Sort with keys of type number first, then string.
			if type(a) == type(b) then
				return a < b
			elseif type(a) == 'number' then
				return true
			end
		end)
	for _, v in ipairs(keys) do -- Add named args based on sorted parameter list
		ret[#ret + 1] = seps.pipe
		ret[#ret + 1] = tostring(v)
		ret[#ret + 1] = seps.equals
		ret[#ret + 1] = invArgs[v]
	end
	ret[#ret + 1] = seps.closeb

	return table.concat(ret)
end

return p