...` blocks. The CSS defined within
* these blocks is then extracted, processed, and injected into the `
`
* section of the generated HTML page.
*
* It also provides a feature to automatically wrap CSS rules for classes
* found within the `` block (e.g., `.myclass { ... }`) with a
* `.wrap_myclass { ... }` equivalent. This is useful for styling elements
* that are automatically wrapped by DokuWiki's `.wrap` classes.
*
* Author: Your Name/Entity (or original author if known)
* Date: 2023-10-27 (or original creation date)
*
* @license GPL 2 (http://www.gnu.org/licenses/gpl.html)
*/
// Import necessary DokuWiki extension classes
use dokuwiki\Extension\ActionPlugin;
use dokuwiki\Extension\EventHandler;
use dokuwiki\Extension\Event;
/**
* Class action_plugin_pagecss
*
* This class extends DokuWiki's ActionPlugin to hook into specific DokuWiki
* events for processing and injecting custom page-specific CSS.
*/
class action_plugin_pagecss extends ActionPlugin {
/**
* Registers the plugin's hooks with the DokuWiki event handler.
*
* This method is called by DokuWiki during plugin initialization.
* It sets up which DokuWiki events this plugin will listen for and
* which methods will handle those events.
*
* @param EventHandler $controller The DokuWiki event handler instance.
*/
public function register(EventHandler $controller) {
// Register a hook to inject custom CSS into the HTML header.
// 'TPL_METAHEADER_OUTPUT' is triggered just before the section is closed.
// 'BEFORE' ensures our CSS is added before other elements that might rely on it.
// '$this' refers to the current plugin instance.
// 'inject_css' is the method that will be called when this event fires.
$controller->register_hook('TPL_METAHEADER_OUTPUT', 'BEFORE', $this, 'inject_css');
// Register a hook to handle metadata caching and extraction of CSS.
// 'PARSER_CACHE_USE' is triggered before DokuWiki attempts to use its parser cache.
// 'BEFORE' allows us to modify the metadata before the page is rendered or cached.
// 'handle_metadata' is the method that will be called.
$controller->register_hook('PARSER_CACHE_USE', 'BEFORE', $this, 'handle_metadata');
}
/**
* Extracts CSS content from `...` blocks within a DokuWiki page.
*
* This method is triggered by the 'PARSER_CACHE_USE' event. It reads the raw
* content of the current wiki page, finds all `` blocks, combines
* their content, and stores it in the page's metadata. It also generates
* `.wrap_classname` rules for any classes found in the embedded CSS.
*
* @param \Doku_Event $event The DokuWiki event object, containing page data.
*/
public function handle_metadata(\Doku_Event $event) {
global $ID; // Global variable holding the current DokuWiki page ID.
// Sanitize the page ID to ensure it's safe for file system operations and metadata.
$id = cleanID($ID);
// Get the raw content of the current wiki page. This includes all wiki syntax.
$text = rawWiki($id);
// Use a regular expression to find all occurrences of ... blocks.
// The /s modifier makes the dot (.) match newlines as well, allowing multiline CSS.
// The (.*?) captures the content between the tags non-greedily.
preg_match_all('/(.*?)<\/pagecss>/s', $text, $matches);
// Check if any blocks were found.
if (!empty($matches[1])) {
// If blocks are found, combine all captured CSS content into a single string.
// trim() is used to remove leading/trailing whitespace from each block.
$styles = implode(" ", array_map('trim', $matches[1]));
// If there's actual CSS content after trimming and combining.
if ($styles) {
$extra = ''; // Initialize a variable to hold the generated .wrap_classname styles.
// Find all CSS class selectors (e.g., .myclass) within the extracted styles.
// This regex captures the class name (e.g., 'myclass').
preg_match_all('/\.([a-zA-Z0-9_-]+)\s*\{[^}]*\}/', $styles, $class_matches);
// Iterate over each found class name.
foreach ($class_matches[1] as $classname) {
// Construct a regex pattern to find the full CSS rule for the current class.
$pattern = '/\.' . preg_quote($classname, '/') . '\s*\{([^}]*)\}/';
// Match the specific class rule in the combined styles.
if (preg_match($pattern, $styles, $style_block)) {
// Extract the content of the CSS rule (e.g., "color: red; font-size: 1em;").
$css_properties = $style_block[1];
// Basic check to avoid malformed or incomplete styles that might contain
// unclosed braces, which could lead to invalid CSS.
if (strpos($css_properties, '{') === false && strpos($css_properties, '}') === false) {
// Append the generated .wrap_classname rule to the $extra string.
// DokuWiki often wraps user content in divs with classes like .wrap_someclass.
// This ensures that custom CSS can target these wrapped elements.
$extra .= ".wrap_$classname {{$css_properties}}\n";
}
}
}
// Append the generated .wrap_classname styles to the main $styles string.
$styles .= "\n" . trim($extra);
// IMPORTANT: Prevent premature closing of the ` inside ``,
// this replaces it with `<\style>` which is still valid CSS but doesn't close the tag.
$styles = str_replace('', '<\/', $styles);
// Store the processed CSS styles in the page's metadata.
// This makes the styles available later when the HTML header is generated.
p_set_metadata($id, ['pagecss' => ['styles' => $styles]]);
// Invalidate the DokuWiki parser cache for this page whenever its content changes.
// This ensures that if the blocks are modified, the metadata is re-extracted.
$event->data['depends']['page'][] = $id;
return; // Exit the function as styles were found and processed.
}
}
// If no blocks were found or they were empty,
// ensure the 'pagecss' metadata entry is reset to an empty string.
// This prevents old CSS from being injected if the blocks are removed.
p_set_metadata($id, ['pagecss' => ['styles' => '']]);
}
/**
* Injects the extracted CSS into the HTML `` section of the DokuWiki page.
*
* This method is triggered by the 'TPL_METAHEADER_OUTPUT' event. It retrieves
* the stored CSS from the page's metadata and adds it to the event data,
* which DokuWiki then uses to build the `` section.
*
* @param Doku_Event $event The DokuWiki event object, specifically for metaheader output.
*/
public function inject_css(Doku_Event $event) {
global $ID; // Global variable holding the current DokuWiki page ID.
// Sanitize the page ID.
$id = cleanID($ID);
// Retrieve the 'pagecss' metadata for the current page.
$data = p_get_metadata($id, 'pagecss');
// Extract the 'styles' content from the metadata, defaulting to an empty string if not set.
$styles = isset($data['styles']) ? $data['styles'] : '';
// Check if there are valid styles to inject and ensure it's a string.
if ($styles && is_string($styles)) {
// Add the custom CSS to the event's 'style' array.
// DokuWiki's template system will then automatically render this
// as a