# Extension:Code

A MediaWiki extension that builds on [SyntaxHighlight]
to provide the following (all in a configurable manner):

* shorter tags  
  e.g. `<query>` instead of `<syntaxhighlight lang=sparql>`

* code actions  
  e.g. automatically link the [WDQS] for SPARQL code blocks[^1]

* code pages  
  e.g. automatically higlight pages with names ending in `.rq`
  as SPARQL (and also display the code actions for them)

* customizable code display via Lua/[Scribunto]  
  e.g. automatically link Wikidata identifiers in code blocks


## Example configuration

```php
$wgCode_namespacesWithCodePages[NS_MAIN] = true;

$wgCode_languages[] = [
	'tag' => 'query',
	'pygmentsLexer' => 'sparql',
	'actions' => [
		'run' => 'https://query.wikidata.org/#$code',
		'embed' => 'https://query.wikidata.org/embed.html#$code',
	],
	'suffix' => '.rq',
];
```

## Customizable code display

The display of code blocks can be customized via Lua/[Scribunto].  For example
if you specify e.g. `"scribuntoModule" => "QueryCode"` for a language then this
extension will additionally invoke the `Module:QueryCode` Scribunto module for
every code tag and code page. Such a module could look as follows:

```lua
local p = {}

p.formatCode = function(frame)
    local code, tag, is_code_page = frame.args[1], frame.args[2], frame.args[3]
    local formattedCode = frame.args[4]
    formattedCode = formattedCode:gsub('[QP][0-9]+', function(m)
       local a = mw.html.create('a')
       a:attr('href', 'https://www.wikidata.org/entity/' .. m)
       a:wikitext(m)
       return tostring(a)
    end)
    return formattedCode;
end

p.additionalOutput = function(frame)
    local code, tag, is_code_page = frame.args[1], frame.args[2], frame.args[3]
    -- HTML returned here is displayed after the code action links
end

return p
```

Note that the returned strings are not parsed as Wikitext they must already be
HTML; any dangerous tags and attributes are removed via MediaWiki's builtin
`Sanitizer` class.

## Linking code actions

Code actions can be linked from other pages via the
`Special:CodeAction` special page, e.g. `Special:CodeAction/run/Example.rq`
attempts to execute the `run` action for the `Example.rq` code page
and redirect the user accordingly.

## Installation

1. Place the extension in your extensions directory.
2. Add `wfLoadExtension('Code');` to your `LocalSettings.php`.
3. Visit `Special:CodeAction` it will tell you what other configuration you need.

(If you want syntax highlighting via [SyntaxHighlight], additionally add
`wfLoadExtension('SyntaxHighlight_GeSHi');` to your `LocalSettings.php`).


[^1]: While this can also be achieved just via MediaWiki templates,
this bears the problem that `|` has to be escaped as `{{!}}`, which can
be quite annoying for languages like SPARQL that use `|` as an operator.

[SyntaxHighlight]: https://www.mediawiki.org/wiki/Special:MyLanguage/Extension:SyntaxHighlight
[Scribunto]: https://www.mediawiki.org/wiki/Special:MyLanguage/Extension:Scribunto
[WDQS]: https://query.wikidata.org/