/core/utilities/calais/opencalais.php

<?php



/**

* Open Calais Tags

* Last updated 7/6/2009

* Copyright (c) 2009 Dan Grossman 

* http://www.dangrossman.info

* 

* Please see http://www.dangrossman.info/open-calais-tags

* for documentation and license information.

*/



class OpenCalaisException extends Exception {}



class OpenCalais {



	const APIURL = "http://api1.opencalais.com/enlighten/rest/";

	

	private $apikey;

	private $allowDistribution = false;

	private $allowSearch = false;

	private $externalID = '';

	private $submitter = 'Open Calais Tags';

	private $contentType = 'text/txt';

	private $outputFormat = 'xml/rdf';

	private $prettyTypes = true;

	private $entities;

	

	public function OpenCalais($apikey = null) {

		if (empty($apikey)) {

			throw new OpenCalaisException("You must provide an OpenCalais API key to use this class.");

		} else {

			$this->apikey = $apikey;

		}

		$this->entities = array();

	}

	

	public function getAllowDistribution() { return $this->allowDistribution; } 

	public function getAllowSearch() { return $this->allowSearch; } 

	public function getExternalID() { return $this->externalID; } 

	public function getSubmitter() { return $this->submitter; } 

	public function getContentType() { return $this->contentType; } 

	public function getOutputFormat() { return $this->outputFormat; } 

	public function getPrettyTypes() { return $this->prettyTypes; }

	public function setAllowDistribution($x) { $this->allowDistribution = $x; } 

	public function setAllowSearch($x) { $this->allowSearch = $x; } 

	public function setExternalID($x) { $this->externalID = $x; } 

	public function setSubmitter($x) { $this->submitter = $x; } 

	public function setContentType($x) { $this->contentType = $x; } 

	public function setOutputFormat($x) { $this->outputFormat = $x; }

	public function setPrettyTypes($x) { $this->prettyTypes = $x; }

	

	public function getEntities($content) {

	

		$response = $this->callAPI($content);

		

		$xml = substr($response, strpos($response, 'c:document'));		

		$pattern = '#' . preg_quote('<c:name>', '#') . '(.*?)' . preg_quote('</c:name>', '#') . '#ms';

		$matches = preg_match_all($pattern, $xml, $rdf, PREG_SET_ORDER);

		

		foreach ($rdf as $arr) {

			$this->addEntity($arr[1]);

		}

		

		return $this->entities;



	}

	

	private function addEntity($val) {

	

		if (!in_array($val, $this->entities))

			$this->entities[] = $val;

			

	}

	

	private function callAPI($content, $title = null) {

	

		$postdata['licenseID'] = $this->apikey;

	

		$postdata['paramsXML'] = 

			  '<c:params xmlns:c="http://s.opencalais.com/1/pred/"'

			. ' xmlns:rdf="http://www.w3.org/1999/02/22-rdf-syntax-ns#">'

			. '	<c:processingDirectives c:contentType="' . $this->contentType

			. '" c:outputFormat="' . $this->outputFormat . '" c:enableMetadataType="SocialTags"></c:processingDirectives>'

			. '	<c:userDirectives c:allowDistribution="' . $this->allowDistribution 

			. '" c:allowSearch="' . $this->allowSearch . '" c:externalID="' . $this->externalID 

			. '" c:submitter="' . $this->submitter . '"></c:userDirectives>'

			. '	<c:externalMetadata></c:externalMetadata>'

			. '</c:params>';

		

		if (!empty($content)) {

			$postdata['content'] = $content;

		} else {

			throw new OpenCalaisException("Content to analyze is empty.");

		}

		

		$poststring = $this->urlencodeArray($postdata);

			

		$ch = curl_init();

		curl_setopt($ch, CURLOPT_URL, self::APIURL);

		curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);

		curl_setopt($ch, CURLOPT_HEADER, 0);

		curl_setopt($ch, CURLOPT_POSTFIELDS, $poststring);

		curl_setopt($ch, CURLOPT_POST, 1);

		$response = html_entity_decode(curl_exec($ch));

		

		if (strpos($response, "<Exception>") !== false) {

			$text = preg_match("/\<Exception\>(.*)\<\/Exception\>/mu", $response, $matches);

			throw new OpenCalaisException($matches[1]);

		}

		

		return $response;

		

	}

	

	private function urlencodeArray($array) {

		foreach ($array as $key => $val) {

			if (!isset($string)) {

				$string = $key . "=" . urlencode($val);

			} else {

				$string .= "&" . $key . "=" . urlencode($val);

			}

		}

		return $string;

	}



}



?>