Category handler

{{#if:
  {{#ifeq: {{lc: {{{nocat|}}} }} | true
  | dontcat    <!--"nocat=true", don't categorize-->
  }}{{#ifeq: {{lc: {{{categories|}}} }} | no
  | dontcat
  }}{{#switch: {{lc: {{{category2|¬}}} }}
  | yes
  | ¬   =   <!--Not defined-->
  | #default = dontcat   <!--"category2 = no/'defined but empty'/'anything'"-->
  }}{{#switch: {{lc: {{{subpage|}}} }}
  | no = 
    {{basepage subpage
    | 
    | dontcat    <!--"subpage=no" and on a subpage-->
    | page = {{{page|}}}   <!--For testing-->
    }}
  | only = 
    {{basepage subpage
    | dontcat    <!--"subpage=only" and not on a subpage-->
    | page = {{{page|}}}   <!--For testing-->
    }}
  }}

|   <!--Don't categorise (result was "dontcat" or "dontcatdontcat" and so on)-->
| <!--Check blacklist-->
  {{#switch:
    {{#ifeq: {{lc: {{{nocat|}}} }} | false
    |   <!--"nocat=false", skip blacklist check-->
    | {{#ifeq: {{lc: {{{categories|}}} }} | yes
      |   <!--Skip blacklist check-->
      | {{#ifeq: {{lc: {{{category2|}}} }} | yes
        |   <!--Skip blacklist check-->
        | {{category handler/blacklist| page = {{{page|}}} }}   <!--Check blacklist-->
        }}
      }}
    }}
  | hide = <!--Blacklist returned "hide", don't categorize-->
  | #default  = 
    <!--Check if any namespace parameter is defined-->
    {{#ifeq: h0#384!5nea+w9 | {{{all| {{{main| {{{talk| {{{user| {{{file| {{{mediawiki| {{{template| {{{help| {{{category| {{{other| h0#384!5nea+w9 }}} }}} }}} }}} }}} }}} }}} }}} }}} }}}
    | <!--No namespace parameters fed, basic usage-->
      {{namespace detect
      | main = {{{1|}}}
      | file = {{{1|}}}
      | help = {{{1|}}}
      | category = {{{1|}}}
      | page = {{{page|}}}   <!--For testing and demonstration-->
      }}
    | <!--Namespace parameters fed, advanced usage.
          If "data" is a number, return the corresponding 
          numbered parameter, else return "data".  -->
      {{{all|}}}{{category handler/numbered
      | 1 = {{{1|}}}
      | 2 = {{{2|}}}
      | 3 = {{{3|}}}
      | 4 = {{{4|}}}
      | 5 = {{{5|}}}
      | 6 = {{{6|}}}
      | 7 = {{{7|}}}
      | 8 = {{{8|}}}
      | 9 = {{{9|}}}
      | 10 = {{{10|}}}
      | data = 
        <!--Check what namespace, and return the data for it.
            Respecting empty parameters on purpose.  -->
        {{namespace detect
        | main = {{{main| {{{other|}}} }}}
        | talk = {{{talk| {{{other|}}} }}}
        | user = {{{user| {{{other|}}} }}}
        | file = {{{file| {{{image| {{{other|}}} }}} }}}
        | mediawiki = {{{mediawiki| {{{other|}}} }}}
        | template = {{{template| {{{other|}}} }}}
        | help = {{{help| {{{other|}}} }}}
        | category = {{{category| {{{other|}}} }}}
        | other = {{{other|}}}  <!--Namespace special or a new namespace-->
        }}
      }}
    }}
  }}
}}<noinclude>[[Category:Templates]]</noinclude>