# Module:Template invocation

-- 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 = '',
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