# Module:Namespace detect

---
-- --  
-- NAMESPACE DETECT --  
-- --  
-- 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. The module can also use the --  
-- corresponding subject namespace value if it is used on a talk page. Parameter names --  
-- can be configured for different wikis by altering the values in the "cfg" table. --  
-- --  
---

---
-- Configuration data --  
-- Language-specific parameter names can be set here. --  
---

local cfg = {}  

-- This parameter displays content for the main namespace:  
cfg.main = 'main'  

-- This parameter displays in talk namespaces:  
cfg.talk = 'talk'  

-- This parameter displays content for "other" namespaces (namespaces for which  
-- parameters have not been specified, or for when cfg.demospace is set to cfg.other):  
cfg.other = 'other'  

-- This parameter makes talk pages behave as though they are the corresponding subject namespace.  
-- Note that this parameter is used with Module:Yesno. Edit that module to change  
-- the default values of "yes", "no", etc.  
cfg.subjectns = 'subjectns'  

-- This parameter sets a demonstration namespace:  
cfg.demospace = 'demospace'  

-- This parameter sets a specific page to compare:  
cfg.page = 'page'  

-- The header for the namespace column in the wikitable containing the list of possible subject-space parameters.  
cfg.wikitableNamespaceHeader = 'Namespace'  

-- The header for the wikitable containing the list of possible subject-space parameters.  
cfg.wikitableAliasesHeader = 'Aliases'  

---
-- End configuration data --  
---

local yesno = require('Module:Yesno')  

local p = {}  

function p.getPageObject(page)  
-- Get the page object, passing the function through pcall in case we are over the expensive function count limit.  
if page then  
local noError, pageObject = pcall(mw.title.new, page)  
if not noError then  
return nil  
else  
return pageObject  
end  
else  
return mw.title.getCurrentTitle  
end  
end  

function p.getParamMappings  
--[[ Returns a table of how parameter names map to namespace names. The keys are the actual namespace  
names, in lower case, and the values are the possible parameter names for that namespace, also in  
lower case. The table entries are structured like this:  
{  
[''] = {'main'},  
['wikipedia'] = {'wikipedia', 'project', 'wp'},  
...  
}  
local mappings = {}  
mappings[mw.ustring.lower(mw.site.namespaces[0].name)] = {cfg.main}  
mappings[cfg.talk] = {cfg.talk}  
for nsid, ns in pairs(mw.site.subjectNamespaces) do  
if nsid ~= 0 then -- Exclude main namespace.  
local nsname = mw.ustring.lower(ns.name)  
local canonicalName = mw.ustring.lower(ns.canonicalName)  
mappings[nsname] = {nsname}  
if canonicalName ~= nsname then  
table.insert(mappings[nsname], canonicalName)  
end  
for _, alias in ipairs(ns.aliases) do  
table.insert(mappings[nsname], mw.ustring.lower(alias))  
end  
end  
end  
return mappings  
end  

local function getNamespace(args)  
-- Gets the namespace name from the page object.  
local page = args[cfg.page]  
local demospace = args[cfg.demospace]  
local subjectns = args[cfg.subjectns]  
local ret  
if demospace then  
-- Handle "demospace = main" properly.  
if mw.ustring.lower(demospace) == cfg.main then  
ret = mw.site.namespaces[0].name  
else  
ret = demospace  
end  
else  
local pageObject = p.getPageObject(page)  
if pageObject then  
if pageObject.isTalkPage then  
-- If cfg.subjectns is set, get the subject namespace, otherwise use cfg.talk.  
if yesno(subjectns) then  
ret = mw.site.namespaces[pageObject.namespace].subject.name  
else  
ret = cfg.talk  
end  
else  
ret = pageObject.nsText  
end  
else  
return nil -- return nil if the page object doesn't exist.  
end  
end  
ret = mw.ustring.gsub(ret, '_', ' ')  
return mw.ustring.lower(ret)  
end  

function p._main(args)  
-- Get the namespace to compare the parameters to, and the parameter mapping table.  
local namespace = getNamespace(args)  
local mappings = p.getParamMappings  
-- Check for any matches in the namespace arguments. The order we check them doesn't matter,  
-- as there can only be one match.  
for ns, params in pairs(mappings) do  
if ns == namespace then  
-- Check all aliases for matches. The default local namespace is checked first, as  
-- checked these before alias names.  
for _, param in ipairs(params) do  
if args[param] ~= nil then  
return args[param]  
end  
end  
end  
end  
-- If there were no matches, return parameters for other namespaces. This happens if there  
-- was no text specified for the namespace that was detected or if the demospace parameter  
-- is not a valid namespace. Note that the parameter for the detected namespace must be  
-- completely absent for this to happen, not merely blank.  
if args[cfg.other] ~= nil then  
return args[cfg.other]  
end  
end  

function p.main  
-- If called via #invoke, use the args passed into the invoking template, or the args  
-- passed to #invoke if any exist. Otherwise assume args are being passed directly in.  
local origArgs  
if == mw.getCurrentFrame then  
origArgs = :getParent.args  
for k, v in pairs(.args) do  
origArgs = .args  
break  
end  
else  
origArgs =  
end  
-- Trim whitespace and remove blank arguments for demospace and page parameters.  
local args = {}  
for k, v in pairs(origArgs) do  
if type(v) == 'string' then  
v = mw.text.trim(v) -- Trim whitespace.  
end  
if k == cfg.demospace or k == cfg.page then  
if v ~= '' then  
args[k] = v  
end  
else  
args[k] = v  
end  
end  
return p._main(args)  
end  

function p.table  
-- Create a wikitable of all subject namespace parameters, for documentation purposes. The talk  
parameter is optional, in case it needs to be excluded in the documentation.  

local useTalk = type == 'table' and type(.args) == 'table' and .args.talk == 'yes' -- Whether to use the talk parameter.  
local mappings = p.getParamMappings  
-- Start the wikitable.  
local ret = '{|'  
.. '\n|-'  
.. '\n! ' .. cfg.wikitableNamespaceHeader  
.. '\n! ' .. cfg.wikitableAliasesHeader  

-- Generate the row for the main namespace, as we want this to be first in the list.  
ret = ret .. '\n|-'  
.. '\n| <code>' .. cfg.main .. '</code>'  
.. '\n|'  
if useTalk then  
ret = ret .. '\n|-'  
.. '\n| <code>' .. cfg.talk .. '</code>'  
.. '\n|'  
end  
-- Enclose all parameter names in <code> tags.  
for ns, params in pairs(mappings) do  
if ns ~= mw.site.namespaces[0].name then  
for i, param in ipairs(params) do  
mappings[ns][i] = '<code>' .. param .. '</code>'  
end  
end  
end  
-- Generate the other wikitable rows.  
for ns, params in pairs(mappings) do  
if ns ~= mw.site.namespaces[0].name then -- Ignore the main namespace.  
ret = ret .. '\n|-'  
.. '\n| ' .. params[1]  
.. '\n| ' .. table.concat(params, ', ', 2)  
end  
end  
-- End the wikitable.  
ret = ret .. '\n|-'  
.. '\n|}'  
return ret  
end  

return p