# Module:Template parameter value

local p = {}
local PrepareText = require("Module:Wikitext Parsing").PrepareText  
local function getTitle(title)
local success, titleObj = pcall(mw.title.new, title)
if success then return titleObj
else return nil end
end  
--string.gmatch will check the largest block it can without re-scanning whats inside, but we need whats inside
local function matchAllTemplates(str)
local matches = {}
for template in string.gmatch(str, "{%b{}}") do
table.insert(matches, template)
local innerContent = string.sub(template, 3, -3)
for _,subtemplate in next,matchAllTemplates(innerContent) do
table.insert(matches, subtemplate)
end
end
return matches
end  
--Forked version of getParameters from Module:Transcluder with extra features removed
local function escapeString(str)
return string.gsub(str, '[%^%$%(%)%.%[%]%*%+%-%?%%]', '%%%0')
end
local function getParameters(template)
local parameters, parameterOrder = {}, {}
local params = string.match(template, '')
if params then
local count = 0
-- Temporarily replace pipes in subtemplates and wikilinks to avoid chaos
for subtemplate in string.gmatch(params, '{%b{}}') do
params = string.gsub(params, escapeString(subtemplate), string.gsub(subtemplate, ".", {["%"]="%%", ["|"]="@@:@@", ["="]="@@_@@"}) )
end
for wikilink in string.gmatch(params, '%[%b[]%]') do
params = string.gsub(params, escapeString(wikilink), string.gsub(wikilink, ".", {["%"]="%%", ["|"]="@@:@@", ["="]="@@_@@"}) )
end
for parameter in mw.text.gsplit(params, '|') do
local parts = mw.text.split(parameter, '=')
local key = mw.text.trim(parts[1])
local value
if #parts == 1 then
value = key
count = count + 1
key = tostring(count)
else
value = mw.text.trim(table.concat(parts, '=', 2))
end
value = string.gsub(string.gsub(value, '@@:@@', '|'), '@@_@@', '=')
key = string.gsub(string.gsub(key, '@@:@@', '|'), '@@_@@', '=')
table.insert(parameterOrder, key)
parameters[key] = value
end
end
return parameters, parameterOrder
end  
-- Returns a table containing parameters and a table with the order in which each of their values were found.
-- Since this considers all subtemplates, a single parameter is expected to have multiple values.
-- E.g.
-- Would return {X={"", "Value", "Yes"}, Y={"Other value", "P"}}
local function getAllParameters(template, ignore_blank, only_subtemplates)
local parameterTree = setmetatable({}, {
__index = function(self,key)
rawset(self,key,{})
return rawget(self,key)
end
})
local params, paramOrder = getParameters(template)
for _,key in ipairs(paramOrder) do
local value = params[key]
if not ignore_blank or value ~= "" then
if not only_subtemplates then
table.insert(parameterTree[key], value) --Insert the initial value into the tree
end
for subtemplate in string.gmatch(value, "{%b{}}") do --And now check for subvalues
local subparams = getAllParameters(subtemplate, ignore_blank)
for subkey,subset in next,subparams do
for _,subvalue in ipairs(subset) do
table.insert(parameterTree[subkey], subvalue) --And add any we find to our tree
end
end
end
end
end
return parameterTree
end  
--Module entry point. Returns a success boolean and either the target template or why it failed
function p.getTemplate(page, templates, options)
if not templates then --Required parameters
return false, "Missing required parameter 'templates'"
end
options = options or {}  
local template_index = tonumber(options.template_index) or 1
local treat_as_regex = options.treat_as_regex or false
if type(templates) == "string" then
-- TODO: Find a good way to allow specifying multiple templates via template invocation
-- (Modules can just provide a table so no concerns there)
-- Comma splitting is a bad idea (lots of templates have a comma in their name)
templates = {templates}
end  
local title = getTitle(page)
if title == nil then
return false, "Requested title doesn't exist"
end
local content = PrepareText(title:getContent or "")  
local foundTemplates = 0
for _,template in next,matchAllTemplates(content) do
for _,wantedTemplate in pairs(templates) do
if not treat_as_regex then
wantedTemplate = escapeString(wantedTemplate)
end
local firstLetter = string.sub(wantedTemplate, 1, 1)
local firstUpper, firstLower = firstLetter:upper, firstLetter:lower
if firstUpper ~= firstLower then
wantedTemplate = "[" .. firstUpper .. firstLower .. "]" .. string.sub(wantedTemplate, 2)
end
if string.match(template, "^
--Module entry point. Returns a success boolean and either the target parameter's value or why it failed
function p.getParameter(page, templates, parameter, options)
if not (templates and parameter) then --Required parameters
return false, "Missing required parameters 'templates' and 'parameter'"
end
parameter = tostring(parameter) --Force consistency
options = options or {}  
local success, text = p.getTemplate(page, templates, options)
if not success then
return success, text
else
local parameter_index = tonumber(options.parameter_index) or 1
local ignore_subtemplates = options.ignore_subtemplates or false
local only_subtemplates = options.only_subtemplates or false
local ignore_blank = options.ignore_blank or false  
local value
if ignore_subtemplates then
value = getParameters(text)[parameter] or ""
else
local params = getAllParameters(text, ignore_blank, only_subtemplates)
value = params[parameter][parameter_index] or ""
end  
value = string.gsub(value, "</?%a*include%a*>", "")
value = mw.text.trim(value) --technically wrong in some cases but not a big issue
return true, mw.text.decode(value) --decode due to PrepareText
end
end  
--Template entry point. Returns either "yes" or nothing depending on if the wanted template is found
--Will return error text if no template is provided
function p.hasTemplate
local args = require('Module:Arguments').getArgs
local yesno = require("Module:Yesno")
local page = args[1] or args.page
local template = args[2] or args.template
local template_index = tonumber(args[3] or args.N) or 1
if not template or template == "" then
return '<span>No template provided for hasTemplate</span>'
end
local follow = yesno(args.follow) or false
if follow then
page = require("Module:Redirect").luaMain(page)
end
local options = {
template_index = template_index,
treat_as_regex = yesno(args.treat_as_regex) or false,
}  
local success, _ = p.getTemplate(page, template, options)
return success and "yes" or ""
end  
--Template entry point for getParameter. Returns an empty string upon failure
function p.main
local args = require('Module:Arguments').getArgs(, {
wrappers = 'Template:Template parameter value'
})
local yesno = require("Module:Yesno")
local options = {
template_index = args[3] or args.template_index,
parameter_index = args[5] or args.parameter_index,
ignore_subtemplates = yesno(args.ignore_subtemplates or args.ist) or false,
only_subtemplates = yesno(args.only_subtemplates) or false,
ignore_blank = yesno(args.ignore_blank) or false,
treat_as_regex = yesno(args.treat_as_regex) or false,
}
local page = args[1] or args.page
local template = args[2] or args.template
local parameter = args[4] or args.parameter
local success, result = p.getParameter(page, template, parameter, options)
if not success then
return ""
else
if args.dontprocess then
return result
else
return :preprocess(result)
end
end
end  
--Backwards compatability
p.getValue = p.getParameter
--Potentially useful module entry points
p.matchAllTemplates = matchAllTemplates
p.getParameters = getParameters
p.getAllParameters = getAllParameters  
return p