查看“模板:LangSwitch”的源代码

<!-- Documentation of code Snippet: 
 1) "{{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}}" - is the chosen language, either set by parameter "lang=xx" 
    or by language of the user "{{int:Lang}}"
 2) "{{{ {{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}} |}}}" - is the input parameter matching the language for example {{{xx|}}}
 3) Without the fallback templates the LangSwitch template would be 
{{{ 
 {{#switch: {{{ {{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}} |}}} // switch based on input parameter matching the language ie. xx
  | ~        = empty                                    // if |xx=~| than the template will return {{{empty}}} which is empty
  |          = {{#if: {{{default|}}} | default | en }}  // if xx is undefined or empty |xx=| than return {{{default}}} or {{{en}}}
  | #default = {{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}} // for all other cases return {{{xx|}}}
 }}
|}}}

The actual template is bit more complicated calling templates {{GetFallback}} and {{GetFallback2}} to allow language fallback. For example if desired encoding is "sr-ec" (Serbian using Cyrillic alphabet) than the fall back would be "sr" (Serbian))
-->{{{ 
  {{#switch: {{{ {{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}} |}}} 
  | ~ = empty
  |   = {{#switch: {{{ {{GetFallback| {{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}} |default=default}} |}}} 
    | ~ = empty
    |   = {{#switch: {{{ {{GetFallback2| {{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}} |default=default}} |}}} 
      | ~        = empty
      |          = {{#if: {{{default|}}} | default | en }}
      | #default = {{GetFallback2| {{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}} |default=default}} 
      }} 
    | #default = {{GetFallback| {{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}} |default=default}} 
    }}
  | #default = {{#if:{{{lang|}}}|{{{lang}}}|{{int:Lang}}}} 
  }} 
|}}}<includeonly>{{#ifeq:{{NAMESPACE}}|File||{{#if:{{{en|}}}{{{default|}}}{{{nocat|<noinclude>1</noinclude>}}}||[[Category:LangSwitch template without English version]]}}}}</includeonly><noinclude>

{{Documentation}}

</noinclude>
<noinclude>[[Category:语言模板]]</noinclude>