58 lines
1.4 KiB
PHP
58 lines
1.4 KiB
PHP
<?php
|
|
|
|
/**
|
|
* A decorator for File or a subclass that provides a method for extracting full-text from the file's external contents.
|
|
* @author mstephens
|
|
*
|
|
*/
|
|
abstract class FileTextExtractor extends Object {
|
|
/**
|
|
* Set priority from 0-100.
|
|
* The highest priority extractor for a given content type will be selected.
|
|
*
|
|
* @var int
|
|
*/
|
|
public static $priority = 50;
|
|
|
|
protected static $sorted_extractor_classes = null;
|
|
|
|
/**
|
|
* @param DataObject $file
|
|
* @return FileTextExtractor
|
|
*/
|
|
static function for_file($file) {
|
|
$extension = strtolower($file->getExtension());
|
|
|
|
if (!self::$sorted_extractor_classes) {
|
|
// Generate the sorted list of extractors on demand.
|
|
$classes = ClassInfo::subclassesFor("FileTextExtractor");
|
|
array_shift($classes);
|
|
$sortedClasses = array();
|
|
foreach($classes as $class) $sortedClasses[$class] = Object::get_static($class, 'priority');
|
|
arsort($sortedClasses);
|
|
|
|
self::$sorted_extractor_classes = $sortedClasses;
|
|
}
|
|
foreach(self::$sorted_extractor_classes as $className => $priority) {
|
|
$formatter = new $className();
|
|
if(in_array($extension, $formatter->supportedExtensions())) {
|
|
return $formatter;
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Return an array of content types that the extractor can handle.
|
|
* @return unknown_type
|
|
*/
|
|
abstract function supportedExtensions();
|
|
|
|
/**
|
|
* Given a file object, extract the contents as text
|
|
* @param $file
|
|
* @return unknown_type
|
|
*/
|
|
abstract function getContent($file);
|
|
}
|
|
|
|
?>
|