# Module:Category handler

---
-- --
-- CATEGORY HANDLER --
-- --
-- This module implements the template in Lua, --
-- with a few improvements: all namespaces and all namespace aliases --
-- are supported, and namespace names are detected automatically for --
-- the local wiki. This module requires Module:Namespace detect --
-- and Module:Yesno to be available on the local wiki. It can be --
-- configured for different wikis by altering the values in --
-- Module:Category handler/config, and pages can be blacklisted --
-- from categorisation by using Module:Category handler/blacklist. --
-- --
---  
-- Load required modules
local yesno = require('Module:Yesno')  
-- Lazily load things we don't always need
local mShared, mappings  
local p = {}  
---
-- Helper functions
---  
local function trimWhitespace(s, removeBlanks)
if type(s) ~= 'string' then
return s
end
s = s:match('^%s*(.-)%s*$')
if removeBlanks then
if s ~= '' then
return s
else
return nil
end
else
return s
end
end  
---
-- CategoryHandler class
---  
local CategoryHandler = {}
CategoryHandler.__index = CategoryHandler  
function CategoryHandler.new(data, args)
local obj = setmetatable({ _data = data, _args = args }, CategoryHandler)  
-- Set the title object
do
local pagename = obj:parameter('demopage')
local success, titleObj
if pagename then
success, titleObj = pcall(mw.title.new, pagename)
end
if success and titleObj then
obj.title = titleObj
if titleObj == mw.title.getCurrentTitle then
obj._usesCurrentTitle = true
end
else
obj.title = mw.title.getCurrentTitle
obj._usesCurrentTitle = true
end
end  
-- Set suppression parameter values
for _, key in ipairs{'nocat', 'categories'} do
local value = obj:parameter(key)
value = trimWhitespace(value, true)
obj['_' .. key] = yesno(value)
end
do
local subpage = obj:parameter('subpage')
local category2 = obj:parameter('category2')
if type(subpage) == 'string' then
subpage = mw.ustring.lower(subpage)
end
if type(category2) == 'string' then
subpage = mw.ustring.lower(category2)
end
obj._subpage = trimWhitespace(subpage, true)
obj._category2 = trimWhitespace(category2) -- don't remove blank values
end
return obj
end  
function CategoryHandler:parameter(key)
local parameterNames = self._data.parameters[key]
local pntype = type(parameterNames)
if pntype == 'string' or pntype == 'number' then
return self._args[parameterNames]
elseif pntype == 'table' then
for _, name in ipairs(parameterNames) do
local value = self._args[name]
if value ~= nil then
return value
end
end
return nil
else
error(string.format(
'invalid config key "%s"',
tostring(key)
), 2)
end
end  
function CategoryHandler:isSuppressedByArguments
return
-- See if a category suppression argument has been set.
self._nocat == true
or self._categories == false
or (
self._category2
and self._category2 ~= self._data.category2Yes
and self._category2 ~= self._data.category2Negative  
-- Check whether we are on a subpage, and see if categories are
-- suppressed based on our subpage status.
or self._subpage == self._data.subpageNo and self.title.isSubpage
or self._subpage == self._data.subpageOnly and not self.title.isSubpage
end  
function CategoryHandler:shouldSkipBlacklistCheck
-- Check whether the category suppression arguments indicate we
-- should skip the blacklist check.
return self._nocat == false
or self._categories == true
or self._category2 == self._data.category2Yes
end  
function CategoryHandler:matchesBlacklist
if self._usesCurrentTitle then
return self._data.currentTitleMatchesBlacklist
else
mShared = mShared or require('Module:Category handler/shared')
return mShared.matchesBlacklist(
self.title.prefixedText,
mw.loadData('Module:Category handler/blacklist')
end
end  
function CategoryHandler:isSuppressed
-- Find if categories are suppressed by either the arguments or by
-- matching the blacklist.
return self:isSuppressedByArguments
or not self:shouldSkipBlacklistCheck and self:matchesBlacklist
end  
function CategoryHandler:getNamespaceParameters
if self._usesCurrentTitle then
return self._data.currentTitleNamespaceParameters
else
if not mappings then
mShared = mShared or require('Module:Category handler/shared')
mappings = mShared.getParamMappings(true) -- gets mappings with mw.loadData
end
return mShared.getNamespaceParameters(
self.title,
mappings
end
end  
function CategoryHandler:namespaceParametersExist
-- Find whether any namespace parameters have been specified.
-- We use the order "all" --> namespace params --> "other" as this is what
-- the old template did.
if self:parameter('all') then
return true
end
if not mappings then
mShared = mShared or require('Module:Category handler/shared')
mappings = mShared.getParamMappings(true) -- gets mappings with mw.loadData
end
for ns, params in pairs(mappings) do
for i, param in ipairs(params) do
if self._args[param] then
return true
end
end
end
if self:parameter('other') then
return true
end
return false
end  
function CategoryHandler:getCategories
local params = self:getNamespaceParameters
local nsCategory
for i, param in ipairs(params) do
local value = self._args[param]
if value ~= nil then
nsCategory = value
break
end
end
if nsCategory ~= nil or self:namespaceParametersExist then
-- Namespace parameters exist - advanced usage.
if nsCategory == nil then
nsCategory = self:parameter('other')
end
local ret = {self:parameter('all')}
local numParam = tonumber(nsCategory)
if numParam and numParam >= 1 and math.floor(numParam) == numParam then
-- nsCategory is an integer
ret[#ret + 1] = self._args[numParam]
else
ret[#ret + 1] = nsCategory
end
if #ret < 1 then
return nil
else
return table.concat(ret)
end
elseif self._data.defaultNamespaces[self.title.namespace] then
-- Namespace parameters don't exist, simple usage.
return self._args[1]
end
return nil
end  
---
-- Exports
---  
local p = {}  
function p._exportClasses
-- Used for testing purposes.
return {
CategoryHandler = CategoryHandler
}
end  
function p._main(args, data)
data = data or mw.loadData('Module:Category handler/data')
local handler = CategoryHandler.new(data, args)
if handler:isSuppressed then
return nil
end
return handler:getCategories
end  
function p.main(, data)
data = data or mw.loadData('Module:Category handler/data')
local args = require('Module:Arguments').getArgs(, {
wrappers = data.wrappers,
valueFunc = function (k, v)
v = trimWhitespace(v)
if type(k) == 'number' then
if v ~= '' then
return v
else
return nil
end
else
return v
end
end
})
return p._main(args, data)
end  
return p