Editing Module:Category handler/doc (section)

=== Basic usage ===

This module takes two or more parameters. Here's an example using a hello world program:

<syntaxhighlight lang="lua">
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
</syntaxhighlight>

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|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.