Module:Category handler/doc: Difference between revisions

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This module implements the {{tl|category handler}} template. The category handler template helps other templates to automate both categorization and [[Wikipedia:Category suppression|category suppression]]. For information about using the category handler template in other templates, please see the '''[[Template:Category handler|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.

=== When not to use this module ===

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.

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!'

     return result .. category

end

return p

:'''main''', '''file''', '''help''', '''category''', '''portal''' and '''book'''

But it will ''not'' categorize in any other namespaces, e.g.:

And it will ''not'' categorize on blacklisted pages. (See section [[#Blacklist|blacklist]] below.)

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.

This module takes one or more parameters named after the different page types as listed in section [[#Namespaces|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.'

     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|blacklist]] below.) And if you need to demonstrate (discuss) the module on a talkpage, then you can feed "<code>nocat='true'</code>" to prevent that template from categorizing. (See section [[#Nocat|nocat]] below.) Like this:

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.'

     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 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.'

     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 "<code>nocat=true</code>" to prevent the template from categorizing.  

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.'

     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.

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.'

     return result .. category

end

return p

If "<code>subpage='no'</code>" then this template will ''not'' categorize on subpages. For the rare occasion you ''only'' want to categorize on subpages, then use "<code>subpage='only'</code>". If '''subpage''' is empty or undefined then this template categorizes both on basepages and on subpages.

* If "<code>nocat = true</code>" then this template does ''not'' categorize.

* If "<code>nocat = false</code>" this template categorizes even when on blacklisted pages. (See section [[#Blacklist|blacklist]] above.)

* The nocat parameter also accepts aliases for <code>true</code> and <code>false</code> as defined by [[Module:Yesno]], e.g. "yes", "y", "true", and 1 for <code>true</code>, and "no", "n", "false", and 0 for <code>false</code>.

For backwards compatibility this module also understands the '''categories''' parameter. It works the same as '''nocat'''. Like this:

* If "<code>categories = true</code>" this template categorizes even when on blacklisted pages.

* The categories parameter also accepts aliases for <code>true</code> and <code>false</code> as defined by [[Module:Yesno]], e.g. "yes", "y", "true", and 1 for <code>true</code>, and "no", "n", "false", and 0 for <code>false</code>.

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

return p

When the module code above is used on anything other than a talk page, it will look like this:

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{

     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:

| main = Category:Some cat

| talk = Category:Talk cat

| page = User talk:Example

}}

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

return p

=== Parameters ===

* categories = frame.args.categories / false / true / 'no' / 'yes' / 'n' / 'y' / 'false' / 'true' / 0 / 1

* category2 = frame.args.category or '¬' / 'no' / 'not defined' / '¬' / 'yes'

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.

* [[Wikipedia:WikiProject Category Suppression]] – The WikiProject.

* [[Wikipedia:Namespace]] – Lists all the namespaces.