<?php
-/*
- * tweeper - a Twitter to RSS web scraper
- *
- * Copyright (C) 2013 Antonio Ospite <ospite@studenti.unina.it>
- *
+/**
+ * @file
+ * Tweeper - a Twitter to RSS web scraper.
+ *
+ * Copyright (C) 2013-2015 Antonio Ospite <ao2@ao2.it>
+ *
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
- *
+ *
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
- *
+ *
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
-date_default_timezone_set('UTC');
+require_once 'Symfony/Component/Serializer/autoload.php';
-function formatDate($timestamp)
-{
- return gmdate('D, d M Y H:i:s', $timestamp) . ' GMT';
-}
+use Symfony\Component\Serializer\Serializer;
+use Symfony\Component\Serializer\Encoder\XmlEncoder;
+use Symfony\Component\Serializer\Normalizer\ObjectNormalizer;
+
+date_default_timezone_set('UTC');
+/**
+ * Scrape supported websites and perform conversion to RSS.
+ */
class Tweeper {
- private $USER_AGENT = "Mozilla/5.0 (Windows NT 6.1; rv:22.0) Gecko/20130405 Firefox/22.0";
+ private static $userAgent = "Mozilla/5.0 (Windows NT 6.1; rv:22.0) Gecko/20130405 Firefox/22.0";
- public function __construct($stylesheet) {
- $stylesheet_contents = $this->get_contents($stylesheet);
+ /**
+ * Constructor sets up {@link $generate_enclosure}.
+ */
+ public function __construct($generate_enclosure = FALSE) {
+ $this->generate_enclosure = $generate_enclosure;
+ }
- $xslDoc = new DOMDocument();
- $xslDoc->loadXML($stylesheet_contents);
+ /**
+ * Convert numeric Epoch to the date format expected in a RSS document.
+ */
+ public static function epochToRssDate($timestamp) {
+ if (!is_numeric($timestamp) || is_nan($timestamp)) {
+ $timestamp = 0;
+ }
- $this->xsltProcessor = new XSLTProcessor();
- $this->xsltProcessor->registerPHPFunctions();
- $this->xsltProcessor->importStylesheet($xslDoc);
- }
-
- private function get_contents($uri) {
- # https://www.wjsams.com/c/docs/Wiki/Php-HowToSetUserAgentOnFileGetContents
- $opts = array(
- 'http' => array(
- 'method' => "GET",
- 'header' => join(array(
- "Accept-language: en\r\n",
- "User-Agent: {$this->USER_AGENT}\r\n"
- ))
- )
- );
+ return gmdate(DATE_RSS, $timestamp);
+ }
+
+ /**
+ * Convert generic date string to the date format expected in a RSS document.
+ */
+ public static function strToRssDate($date) {
+ $timestamp = strtotime($date);
+ if (FALSE === $timestamp) {
+ $timestamp = 0;
+ }
+
+ return Tweeper::epochToRssDate($timestamp);
+ }
+
+ /**
+ * Convert string to UpperCamelCase.
+ */
+ public static function toUpperCamelCase($str, $delim = ' ') {
+ $str_upper = ucwords($str, $delim);
+ $str_camel_case = str_replace($delim, '', $str_upper);
+ return $str_camel_case;
+ }
+
+ /**
+ * Get the contents from a URL.
+ */
+ private static function getUrlContents($url) {
+ $ch = curl_init($url);
+ curl_setopt_array($ch, array(
+ CURLOPT_HEADER => FALSE,
+ // Follow http redirects to get the real URL.
+ CURLOPT_FOLLOWLOCATION => TRUE,
+ CURLOPT_RETURNTRANSFER => TRUE,
+ CURLOPT_SSL_VERIFYHOST => FALSE,
+ CURLOPT_SSL_VERIFYPEER => FALSE,
+ CURLOPT_HTTPHEADER => array('Accept-language: en'),
+ CURLOPT_USERAGENT => Tweeper::$userAgent,
+ ));
+ $contents = curl_exec($ch);
+ curl_close($ch);
- $context = stream_context_create($opts);
- $contents = file_get_contents($uri, false, $context);
return $contents;
}
- public function tweep($uri) {
- $html = $this->get_contents($uri);
+ /**
+ * Get the headers from a URL.
+ */
+ private static function getUrlInfo($url) {
+ $ch = curl_init($url);
+ curl_setopt_array($ch, array(
+ CURLOPT_HEADER => TRUE,
+ CURLOPT_NOBODY => TRUE,
+ // Follow http redirects to get the real URL.
+ CURLOPT_FOLLOWLOCATION => TRUE,
+ CURLOPT_RETURNTRANSFER => TRUE,
+ CURLOPT_SSL_VERIFYHOST => FALSE,
+ CURLOPT_SSL_VERIFYPEER => FALSE,
+ CURLOPT_USERAGENT => Tweeper::$userAgent,
+ ));
+ curl_exec($ch);
+ $url_info = curl_getinfo($ch);
+ curl_close($ch);
+
+ return $url_info;
+ }
+
+ /**
+ * Generate an RSS <enclosure/> element.
+ */
+ public static function generateEnclosure($url) {
+ $supported_content_types = array(
+ "application/octet-stream",
+ "application/ogg",
+ "audio/aac",
+ "audio/mp4",
+ "audio/mpeg",
+ "audio/ogg",
+ "audio/vorbis",
+ "audio/wav",
+ "audio/webm",
+ "audio/x-midi",
+ "image/gif",
+ "image/jpeg",
+ "image/png",
+ "video/avi",
+ "video/mp4",
+ "video/mpeg",
+ "video/ogg",
+ );
+
+ $url_info = Tweeper::getUrlInfo($url);
+
+ $supported = in_array($url_info['content_type'], $supported_content_types);
+ if (!$supported) {
+ error_log("Unsupported enclosure content type \"" . $url_info['content_type'] . "\" for URL: " . $url_info['url']);
+ return '';
+ }
+
+ // The RSS specification says that the enclosure element URL must be http.
+ // See http://sourceforge.net/p/feedvalidator/bugs/72/
+ $http_url = preg_replace("/^https/", "http", $url_info['url']);
+
+ $dom = new DOMDocument();
+ $enc = $dom->createElement('enclosure');
+ $enc->setAttribute('url', $http_url);
+ $enc->setAttribute('length', $url_info['download_content_length']);
+ $enc->setAttribute('type', $url_info['content_type']);
+
+ return $enc;
+ }
+
+ /**
+ * Mimic the message from libxml.c::php_libxml_ctx_error_level()
+ */
+ private static function logXmlError($error) {
+ $output = "";
+
+ switch ($error->level) {
+ case LIBXML_ERR_WARNING:
+ $output .= "Warning $error->code: ";
+ break;
+
+ case LIBXML_ERR_ERROR:
+ $output .= "Error $error->code: ";
+ break;
+
+ case LIBXML_ERR_FATAL:
+ $output .= "Fatal Error $error->code: ";
+ break;
+ }
+
+ $output .= trim($error->message);
+
+ if ($error->file) {
+ $output .= " in $error->file";
+ }
+ else {
+ $output .= " in Entity,";
+ }
+
+ $output .= " line $error->line";
+
+ error_log($output);
+ }
+
+ /**
+ * Convert json to XML.
+ */
+ private static function jsonToXml($json, $root_node_name) {
+ // Apparently the ObjectNormalizer used afterwards is not able to handle
+ // the stdClass object created by json_decode() with the default setting
+ // $assoc = false; so use $assoc = true.
+ $data = json_decode($json, $assoc = TRUE);
+ if (!$data) {
+ return NULL;
+ }
+
+ $encoder = new XmlEncoder();
+ $normalizer = new ObjectNormalizer();
+ $serializer = new Serializer(array($normalizer), array($encoder));
+
+ $serializer_options = array(
+ 'xml_encoding' => "UTF-8",
+ 'xml_format_output' => TRUE,
+ 'xml_root_node_name' => $root_node_name,
+ );
+ $xml_data = $serializer->serialize($data, 'xml', $serializer_options);
+ if (!$xml_data) {
+ trigger_error("Cannot serialize data", E_USER_ERROR);
+ return NULL;
+ }
+
+ return $xml_data;
+ }
+
+ /**
+ * Convert the Instagram content to XML.
+ */
+ private function getXmlInstagramCom($html) {
+ // Extract the json data from the html code.
+ $json_match_expr = '/window._sharedData = (.*);/';
+ $ret = preg_match($json_match_expr, $html, $matches);
+ if ($ret !== 1) {
+ trigger_error("Cannot match expression: $json_match_expr\n", E_USER_ERROR);
+ return NULL;
+ }
+
+ return Tweeper::jsonToXml($matches[1], 'instagram');
+ }
+
+ /**
+ * Make the Facebook HTML processable.
+ */
+ private function preprocessHtmlFacebookCom($html) {
+ $html = str_replace('<!--', '', $html);
+ $html = str_replace('-->', '', $html);
+ return $html;
+ }
+
+ /**
+ * Convert the HTML retrieved from the site to XML.
+ */
+ private function htmlToXml($html, $host) {
$xmlDoc = new DOMDocument();
- $xmlDoc->loadHTML($html);
- $output = $this->xsltProcessor->transformToXML($xmlDoc);
+ // Handle warnings and errors when loading invalid HTML.
+ $xml_errors_value = libxml_use_internal_errors(TRUE);
+
+ // If there is a host-specific method to get the XML data, use it!
+ $get_xml_host_method = 'getXml' . Tweeper::toUpperCamelCase($host, '.');
+ if (method_exists($this, $get_xml_host_method)) {
+ $xml_data = call_user_func_array(array($this, $get_xml_host_method), array($html));
+ $xmlDoc->loadXML($xml_data);
+ }
+ else {
+ $xmlDoc->loadHTML($html);
+ }
+
+ foreach (libxml_get_errors() as $xml_error) {
+ Tweeper::logXmlError($xml_error);
+ }
+ libxml_clear_errors();
+ libxml_use_internal_errors($xml_errors_value);
+
+ return $xmlDoc;
+ }
+
+ /**
+ * Load a stylesheet if the web site is supported.
+ */
+ private function loadStylesheet($host) {
+ $stylesheet = "file://" . __DIR__ . "/rss_converter_" . $host . ".xsl";
+ if (FALSE === file_exists($stylesheet)) {
+ trigger_error("Conversion to RSS not supported for $host ($stylesheet not found)", E_USER_ERROR);
+ return NULL;
+ }
+
+ $stylesheet_contents = Tweeper::getUrlContents($stylesheet);
+
+ $xslDoc = new DOMDocument();
+ $xslDoc->loadXML($stylesheet_contents);
+
+ $xsltProcessor = new XSLTProcessor();
+ $xsltProcessor->registerPHPFunctions();
+ $xsltProcessor->setParameter('', 'generate-enclosure', $this->generate_enclosure);
+ $xsltProcessor->importStylesheet($xslDoc);
+
+ return $xsltProcessor;
+ }
+
+ /**
+ * Convert the site content to RSS.
+ */
+ public function tweep($src_url) {
+ $url = parse_url($src_url);
+ if (FALSE === $url || empty($url["host"])) {
+ trigger_error("Invalid URL: $src_url", E_USER_ERROR);
+ return NULL;
+ }
+
+ // Strip the leading www. to be more forgiving on input URLs.
+ $host = preg_replace('/^www\./', '', $url["host"]);
+
+ $xsltProcessor = $this->loadStylesheet($host);
+ if (NULL === $xsltProcessor) {
+ return NULL;
+ }
+
+ $html = Tweeper::getUrlContents($src_url);
+ if (FALSE === $html) {
+ return NULL;
+ }
+
+ $preprocess_html_host_method = 'preprocessHtml' . Tweeper::toUpperCamelCase($host, '.');
+ if (method_exists($this, $preprocess_html_host_method)) {
+ $html = call_user_func_array(array($this, $preprocess_html_host_method), array($html));
+ }
+
+ $xmlDoc = $this->htmlToXml($html, $host);
+ if (NULL === $xmlDoc) {
+ return NULL;
+ }
+
+ $output = $xsltProcessor->transformToXML($xmlDoc);
if (FALSE === $output) {
trigger_error('XSL transformation failed.', E_USER_ERROR);
}
return $output;
}
+
+}
+
+/**
+ * Check if the script is being run from the command line.
+ */
+function is_cli() {
+ return (php_sapi_name() === "cli");
+}
+
+/**
+ * Show the script usage.
+ */
+function usage($argv) {
+ if (is_cli()) {
+ $usage = "{$argv[0]} [-e|-h|--help] <src_url>\n";
+ }
+ else {
+ $usage = htmlentities("{$_SERVER['SCRIPT_NAME']}?src_url=<src_url>&generate_enclosure=<0|1>");
+ }
+
+ return "usage: $usage";
}
-if (isset($_GET['screen_name'])) {
- $screen_name = $_GET['screen_name'];
-} else if (isset($argv[1])) {
- $screen_name = $argv[1];
-} else {
- if (php_sapi_name() != 'cli')
- $usage = htmlentities("{$_SERVER['SCRIPT_NAME']}?screen_name=<screen_name>");
- else
- $usage = "{$argv[0]} <screen_name>\n";
-
- die("usage: $usage");
+/**
+ * Parse command line options.
+ */
+function parse_options_cli($argv, $argc) {
+ $options = array(
+ 'generate_enclosure' => FALSE,
+ );
+
+ if ($argc < 2) {
+ return $options;
+ }
+
+ $cli_options = getopt("eh", array("help"));
+ foreach ($cli_options as $opt => $val) {
+ switch ($opt) {
+ case 'e':
+ $options['generate_enclosure'] = TRUE;
+ break;
+
+ case 'h':
+ case 'help':
+ echo usage($argv);
+ exit(0);
+
+ default:
+ fwrite(STDERR, usage($argv));
+ exit(1);
+ }
+ }
+
+ $options['src_url'] = $argv[count($cli_options) + 1];
+
+ return $options;
}
-$tweeper = new Tweeper('twitter_user_timeline2rss.xsl');
+/**
+ * Parse options passed from a query string.
+ */
+function parse_options_query_string() {
+ $options = array(
+ 'generate_enclosure' => FALSE,
+ );
+
+ if (isset($_GET['src_url'])) {
+ $options['src_url'] = $_GET['src_url'];
+ }
+
+ if (isset($_GET['generate_enclosure'])) {
+ $options['generate_enclosure'] = $_GET['generate_enclosure'] == 1;
+ }
+
+ return $options;
+}
+
+if (is_cli()) {
+ $options = parse_options_cli($argv, $argc);
+ $error_stream = fopen('php://stderr', 'w');
+}
+else {
+ $options = parse_options_query_string();
+ $error_stream = fopen('php://output', 'w');
+}
+
+if (!isset($options['src_url'])) {
+ fwrite($error_stream, usage(is_cli() ? $argv : NULL));
+ exit(1);
+}
-$src_uri = 'https://twitter.com/' . $screen_name;
-echo $tweeper->tweep($src_uri);
+$tweeper = new Tweeper($options['generate_enclosure']);
+echo $tweeper->tweep($options['src_url']);