silverstripe-textextraction/code/extractors/TikaTextExtractor.php
2015-11-18 17:07:31 +13:00

106 lines
2.8 KiB
PHP

<?php
/**
* Enables text extraction of file content via the Tika CLI
*
* {@link http://tika.apache.org/1.7/gettingstarted.html}
*/
class TikaTextExtractor extends FileTextExtractor
{
/**
* Text extraction mode. Defaults to -t (plain text)
*
* @var string
* @config
*/
private static $output_mode = '-t';
/**
* Get the version of tika installed, or 0 if not installed
*
* @return float version of tika
*/
public function getVersion()
{
$code = $this->runShell('tika --version', $stdout);
// Parse output
if (!$code && preg_match('/Apache Tika (?<version>[\.\d]+)/', $stdout, $matches)) {
return $matches['version'];
}
return 0;
}
/**
* Runs an arbitrary and safely escaped shell command
*
* @param string $command Full command including arguments
* @param string &$stdout Standand output
* @param string &$stderr Standard error
* @param string $input Content to pass via standard input
* @return int Exit code. 0 is success
*/
protected function runShell($command, &$stdout = '', &$stderr = '', $input = '')
{
$descriptorSpecs = array(
0 => array("pipe", "r"),
1 => array("pipe", "w"),
2 => array("pipe", "w")
);
// Invoke command
$pipes = array();
$proc = proc_open($command, $descriptorSpecs, $pipes);
if (!is_resource($proc)) {
return 255;
}
// Send content as input
fwrite($pipes[0], $input);
fclose($pipes[0]);
// Get output
$stdout = stream_get_contents($pipes[1]);
fclose($pipes[1]);
$stderr = stream_get_contents($pipes[2]);
fclose($pipes[2]);
// Get result
return proc_close($proc);
}
public function getContent($path)
{
$mode = $this->config()->output_mode;
$command = sprintf('tika %s %s', $mode, escapeshellarg($path));
$code = $this->runShell($command, $output);
if ($code == 0) {
return $output;
}
}
public function isAvailable()
{
return $this->getVersion() > 0;
}
public function supportsExtension($extension)
{
// Determine support via mime type only
return false;
}
public function supportsMime($mime)
{
// Get list of supported mime types
$code = $this->runShell('tika --list-supported-types', $supportedTypes, $error);
if ($code) {
return false;
} // Error case
// Check if the mime type is inside the result
$pattern = sprintf('/\b(%s)\b/', preg_quote($mime, '/'));
return (bool)preg_match($pattern, $supportedTypes);
}
}