Module:Category handler
This module is rated as beta, and is ready for widespread use. It is still new and should be used with some caution to ensure the results are as expected, as bugs may still occur. |
This Lua module is used on 4,640,000+ pages, or roughly 1705% of all pages. To avoid major disruption and server load, any changes should be tested in the module's /sandbox or /testcases subpages, or in your own module sandbox. The tested changes can be added to this page in a single edit. Consider discussing changes on the talk page before implementing them. |
This module implements the {{category handler}} template. The category handler template helps other templates to automate both categorization and category suppression. For information about using the category handler template in other templates, please see the template documentation. Keep reading for information about using the category handler module in other Lua modules, or for information on exporting this module to other wikis.
Use from other Lua modules
[edit]When not to use this module
[edit]For cases where a module only needs to categorise in one of the namespaces main (articles), file (images) or category, then using this module is overkill. Instead, you can simply get a title object using mw.title.getCurrentTitle and check the nsText
field. For example:
local title = mw.title.getCurrentTitle()
if title.nsText == 'File' then
-- do something
end
However, if your module needs to categorize in any other namespace, then we recommend you use this module, since it provides proper category suppression and makes it easy to select how to categorize in the different namespaces.
Namespaces
[edit]This module detects and groups all the different namespaces used on Wikipedia into several types. These types are used as parameter names in this module.
- main = Main/article space, as in normal Wikipedia articles.
- talk = Any talk space, such as page names that start with "Talk:", "User talk:", "File talk:" and so on.
- user, wikipedia, file ... = The other namespaces except the talk pages. Namespace aliases are also accepted. See the table below for the full list.
- other = Any namespaces that were not specified as a parameter to the template. See examples below.
- List of possible namespace parameters
(excluding talk
and other
)
Namespace | Aliases |
---|---|
main
|
|
module
|
|
story
|
|
media
|
|
special
|
|
help
|
|
topic
|
|
newsletter
|
|
timedtext
|
|
portal
|
|
user
|
|
flow test
|
|
wikipedia
|
project , wp
|
event
|
|
draft
|
|
talk
|
|
config
|
|
mos
|
|
category
|
|
file
|
image
|
mediawiki
|
|
template
|
tm
|
Basic usage
[edit]This module takes two or more parameters. Here's an example using a hello world program:
p = {}
local categoryHandler = require( 'Module:Category handler' ).main
function p.main( frame )
local result = 'Hello world!'
local category = categoryHandler{
'[[Category:Somecat]]',
nocat = frame.args.nocat -- So "nocat=true/false" works
}
category = category or '' -- Check that we don't have a nil value for the category variable.
return result .. category
end
return p
The above example uses the default settings for the category handler module. That means the example module will categorize on pages in the following namespaces:
- main, file, help, category, portal and book
But it will not categorize in any other namespaces, e.g.:
- talk, user, wikipedia, mediawiki, template ...
And it will not categorize on blacklisted pages. (See section blacklist below.)
The reason the category handler module does not categorize in some of the namespaces is that in those namespaces most modules and templates are just demonstrated or listed, not used. Thus most modules and templates should not categorize in those namespaces.
Any module or template that is meant for one or more of the namespaces where this module categorizes can use the basic syntax as shown above.
Advanced usage
[edit]This module takes one or more parameters named after the different page types as listed in section namespaces above. By using those parameters you can specify exactly in which namespaces your template should categorize. Like this:
p = {}
local categoryHandler = require( 'Module:Category handler' ).main
function p.main( frame )
local result = 'This is a module meant for articles and talk pages.'
local category = categoryHandler{
main = '[[Category:Somecat1]]', -- Categorize in main (article) space
talk = '[[Category:Somecat2]]', -- Categorize in talk space
nocat = frame.args.nocat -- So "nocat=true/false" works
}
category = category or '' -- Check that we don't have a nil value for the category variable.
return result .. category
end
return p
The above module will only categorize in main and talk space. But it will not categorize on /archive pages since they are blacklisted. (See section blacklist below.) And if you need to demonstrate (discuss) the module on a talkpage, then you can feed "nocat='true'
" to prevent that template from categorizing. (See section nocat below.) Like this:
== My new module == Hey guys, have you seen my new module? {{#invoke:mymodule|main|nocat=true}} Nice, isn't it? --~~~~
Sometimes we want to use the same category in several namespaces, then do like this:
p = {}
local categoryHandler = require( 'Module:Category handler' ).main
function p.main( frame )
local result = 'This is a module used in several namespaces.'
local category = categoryHandler{
main = '[[Category:Somecat1]]',
[ 1 ] = '[[Category:Somecat2]]', -- For help and user space
help = 1,
user = 1,
talk = '', -- No categories on talk pages
other = '[[Category:Somecat3]]', -- For all other namespaces
nocat = frame.args.nocat -- So "nocat=true/false" works
}
category = category or '' -- Check that we don't have a nil value for the category variable.
return result .. category
end
return p
In the above example we use a numbered parameter to feed one of the categories, and then we tell this module to use that numbered parameter for both the help and user space.
The category handler module understands an unlimited number of numbered parameters.
The other parameter defines what should be used in the remaining namespaces that have not explicitly been fed data.
Note the empty but defined talk parameter. That stops this module from showing what has been fed to the other parameter, when in talk space.
The category handler module also has a parameter called all. It works like this:
p = {}
local categoryHandler = require( 'Module:Category handler' ).main
function p.main( frame )
local result = 'This is a module used in all namespaces.'
local category = categoryHandler{
all = '[[Category:Somecat1]]', -- Categorize in all namespaces
nocat = frame.args.nocat -- So "nocat=true/false" works
}
category = category or '' -- Check that we don't have a nil value for the category variable.
return result .. category
end
return p
The above example will categorize in all namespaces, but not on blacklisted pages. If you want to demonstrate that module on a page, then use "nocat=true
" to prevent the template from categorizing.
We suggest avoiding the all parameter, since modules and templates should preferably only categorize in the namespaces they need to.
The all parameter can also be combined with the rest of the parameters. Like this:
p = {}
local categoryHandler = require( 'Module:Category handler' ).main
function p.main( frame )
local result = 'This is a module used in all namespaces.'
local category = categoryHandler{
all = '[[Category:Somecat1]]', -- Categorize in all namespaces
main = '[[Category:Somecat2]]', -- And add this in main space
other = '[[Category:Somecat3]]', -- And add this in all other namespaces
nocat = frame.args.nocat -- So "nocat=true/false" works
}
category = category or '' -- Check that we don't have a nil value for the category variable.
return result .. category
end
return p
If the above module is placed on an article, then it will add the categories "Somecat1" and "Somecat2". But on all other types of pages it will instead add "Somecat1" and "Somecat3". As the example shows, the all parameter works independently of the rest of the parameters.
Subpages
[edit]The category handler module understands the subpage parameter. Like this:
p = {}
local categoryHandler = require( 'Module:Category handler' ).main
function p.main( frame )
local result = 'This is a module used in all namespaces.'
local category = categoryHandler{
subpage = 'no' -- Don't categorize on subpages
wikipedia = '[[Category:Somecat]]',
nocat = frame.args.nocat -- So "nocat=true/false" works
}
category = category or '' -- Check that we don't have a nil value for the category variable.
return result .. category
end
return p
If "subpage='no'
" then this template will not categorize on subpages. For the rare occasion you only want to categorize on subpages, then use "subpage='only'
". If subpage is empty or undefined then this template categorizes both on basepages and on subpages.
Blacklist
[edit]This module has a blacklist of the pages and page types where templates should not auto-categorize. Thus modules that use this meta-template will for instance not categorize on /archive pages and on the subpages of Wikipedia:Template messages.
If you want a template to categorize on a blacklisted page, then feed "nocat = false
" to the module when you place it on the page, thus skipping the blacklist check. Note that this module only categorizes if it has data for the namespace. For instance, if the basic syntax is used (see basic usage above), then even if you set "nocat = false
" the template will not categorize on a talk page, since it has no data for talk pages. But it has data for help space, so on a blacklisted help page it will categorize.
The blacklist is located in the configuration table cfg.blacklist
near the top of the module code.
The "nocat" parameter
[edit]This module understands the nocat parameter:
- If "
nocat = true
" then this template does not categorize. - If nocat is
nil
then this template categorizes as usual. - If "
nocat = false
" this template categorizes even when on blacklisted pages. (See section blacklist above.) - The nocat parameter also accepts aliases for
true
andfalse
as defined by Module:Yesno, e.g. "yes", "y", "true", and 1 fortrue
, and "no", "n", "false", and 0 forfalse
.
Modules and templates that use {{category handler}} should forward nocat, so they too understand nocat. The code "nocat = frame.args.nocat
" shown in the examples on this page does that.
The "categories" parameter
[edit]For backwards compatibility this module also understands the categories parameter. It works the same as nocat. Like this:
- If "
categories = false
" then this template does not categorize. - If categories is empty or undefined then this template categorizes as usual.
- If "
categories = true
" this template categorizes even when on blacklisted pages. - The categories parameter also accepts aliases for
true
andfalse
as defined by Module:Yesno, e.g. "yes", "y", "true", and 1 fortrue
, and "no", "n", "false", and 0 forfalse
.
The "category2" parameter
[edit]For backwards compatibility this template kind of supports the old "category =" parameter. But the parameter name "category" is already used in this module to feed category data for when in category space. So instead this template uses category2 for the usage similar to nocat. Like this:
- If "
category2 =
" (empty but defined), or "category2 = 'no'
", or if category2 is fed any other data (except as described in the next two points), then this template does not categorize. - If category2 is undefined or if "
category2 = '¬'
", then this template categorizes as usual. - If "
category2 = 'yes'
" this template categorizes even when on blacklisted pages.
Categories and text
[edit]Besides from categories, you can feed anything else to this module, for instance some text. Like this:
p = {}
local categoryHandler = require( 'Module:Category handler' ).main
function p.main( frame )
local result = 'This is a module used on talk pages.'
local category = categoryHandler{
talk = '[[Category:Somecat]]',
other = '<p class="error">This module should only be used on talk pages.</p>',
nocat = frame.args.nocat -- So "nocat=true/false" works
}
category = category or '' -- Check that we don't have a nil value for the category variable.
return result .. category
end
return p
When the template above is shown on anything else than a talk page, it will look like this:
- This is a module used on talk pages.
This module should only be used on talk pages.
That text will not show on blacklisted pages, so don't use this method to show any important information. Feeding "nocat = 'true'
" to the template hides the text, just as it suppresses any categories.
The "page" parameter
[edit]For testing and demonstration purposes this module can take a parameter named page. Like this:
p = {}
local categoryHandler = require( 'Module:Category handler' ).main
function p.main( frame )
local category = categoryHandler{
main = 'Category:Some cat',
talk = 'Category:Talk cat',
nocat = frame.args.nocat, -- So "nocat=true/false" works
page = 'User talk:Example'
}
return category
end
return p
In the above code we on purpose left out the brackets around the category names so we see the output on the page. No matter on what kind of page the code above is used it will return this:
- Category:Talk cat
The page parameter makes this module behave exactly as if on that page. Even the blacklist works. The pagename doesn't have to be an existing page.
If the page parameter is empty or undefined, the name of the current page determines the result.
You can make it so your module also understands the page parameter. That means you can test how your template will categorize on different pages, without having to actually edit those pages. Then do like this:
p = {}
local categoryHandler = require( 'Module:Category handler' ).main
function p.main( frame )
local category = categoryHandler{
main = 'Category:Some cat',
talk = 'Category:Talk cat',
nocat = frame.args.nocat, -- So "nocat=true/false" works
page = frame.args.page -- For testing
}
return category
end
return p
Parameters
[edit]List of all parameters:
- First positional parameter - for default settings
- subpage = 'no' / 'only'
- 1, 2, 3 ...
- all = '[[Category:Somecat]]' / 'Text'
- main = 1, 2, 3 ... / '[[Category:Somecat]]' / 'Text'
- ...
- other = 1, 2, 3 ... / '[[Category:Somecat]]' / 'Text'
- nocat = frame.args.nocat / true / false / 'yes' / 'no' / 'y' / 'n' / 'true' / 'false' / 1 / 0
- categories = frame.args.categories / false / true / 'no' / 'yes' / 'n' / 'y' / 'false' / 'true' / 0 / 1
- category2 = frame.args.category or '¬' / / 'no' / not defined / '¬' / 'yes'
- page = frame.args.page / 'User:Example'
Note that empty values to the "main" ... "other" parameters have special meaning (see examples above). The "all" parameter doesn't understand numbered parameters, since there should never be a need for that.
Exporting to other wikis
[edit]This module can be exported to other wikis by changing the configuration values in the cfg
table. All the variable values are configurable, so after the configuration values have been set there should be no need to alter the main module code. Details of each configuration value are included in the module code comments. In addition, this module requires Module:Namespace detect to be available on the local wiki.
See also
[edit]- {{Category handler}} – for using this module with templates, rather than Lua modules.
- Wikipedia:Category suppression – The how-to guide.
- Wikipedia:WikiProject Category Suppression – The WikiProject.
- Wikipedia:Namespace – Lists all the namespaces.
--------------------------------------------------------------------------------
-- --
-- CATEGORY HANDLER --
-- --
-- This module implements the {{category handler}} 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(frame, data)
data = data or mw.loadData('Module:Category handler/data')
local args = require('Module:Arguments').getArgs(frame, {
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