X-Git-Url: https://git.ao2.it/tweeper.git/blobdiff_plain/f10331c2001ba9ac72b8ccede428a98dcd9282e8..9c481b9a71983e1359c91748a7e5150700808599:/tweeper.php?ds=inline diff --git a/tweeper.php b/tweeper.php index 94d91c3..0955a11 100644 --- a/tweeper.php +++ b/tweeper.php @@ -1,108 +1,153 @@ - * +/** + * @file + * Tweeper - a Twitter to RSS web scraper. + * + * Copyright (C) 2013-2015 Antonio Ospite + * * 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 . */ +require_once 'Symfony/Component/Serializer/autoload.php'; + +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 static $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, $generate_enclosure = FALSE) { - $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->setParameter('', 'generateEnclosure', $generate_enclosure); - $this->xsltProcessor->importStylesheet($xslDoc); + return gmdate(DATE_RSS, $timestamp); } - public static function epoch_to_gmdate($timestamp) - { - return gmdate('D, d M Y H:i:s', $timestamp) . ' GMT'; + /** + * Convert generic date string to the date format expected in a RSS document. + */ + public static function strToRssDate($date) { + $timestamp = strtotime($date); + if (FALSE === $timestamp) { + $timestamp = 0; + } + + return Tweeper::epochToRssDate($timestamp); } - public static function str_to_gmdate($date) - { - $timestamp = strtotime($date); - return Tweeper::epoch_to_gmdate($timestamp); - } - - private static function get_contents($uri) { - # https://www.wjsams.com/c/docs/Wiki/Php-HowToSetUserAgentOnFileGetContents - $opts = array( - 'http' => array( - 'method' => "GET", - 'header' => join(array( - "Accept-language: en\r\n", - "User-Agent: {" + Tweeper::$USER_AGENT + "}\r\n" - )) - ) - ); + /** + * 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); + if (FALSE === $contents) { + trigger_error(curl_error($ch)); + } + curl_close($ch); - $context = stream_context_create($opts); - $contents = file_get_contents($uri, false, $context); return $contents; } - private static function get_info($url) - { + /** + * Get the headers from a URL. + */ + private static function getUrlInfo($url) { $ch = curl_init($url); curl_setopt_array($ch, array( - CURLOPT_HEADER => TRUE, - CURLOPT_NOBODY => TRUE, - CURLOPT_FOLLOWLOCATION => TRUE, // follow http redirects to get the real URL - CURLOPT_RETURNTRANSFER => TRUE, - CURLOPT_SSL_VERIFYHOST => FALSE, - CURLOPT_SSL_VERIFYPEER => FALSE, - CURLOPT_USERAGENT => Tweeper::$USER_AGENT, + 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); + if (FALSE === $url_info) { + trigger_error(curl_error($ch)); + } curl_close($ch); return $url_info; } - public static function generate_enclosure($url) - { + /** + * Generate an RSS element. + */ + public static function generateEnclosure($url) { $supported_content_types = array( + "application/octet-stream", "application/ogg", + "application/pdf", "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", ); - $url_info = Tweeper::get_info($url); + $url_info = Tweeper::getUrlInfo($url); $supported = in_array($url_info['content_type'], $supported_content_types); if (!$supported) { @@ -110,24 +155,193 @@ class Tweeper { return ''; } - $dom = new DomDocument(); + // 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', $url_info['url']); + $enc->setAttribute('url', $http_url); $enc->setAttribute('length', $url_info['download_content_length']); $enc->setAttribute('type', $url_info['content_type']); - $dom->appendChild($enc); + 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; + } - return $dom->saveXML($enc); + $output .= trim($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 $xml_data; } - public function tweep($uri) { - $html = Tweeper::get_contents($uri); + /** + * 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); + 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); @@ -135,39 +349,57 @@ class Tweeper { } return $output; } + } -function usage($argv) -{ - if (php_sapi_name() != 'cli') - $usage = htmlentities("{$_SERVER['SCRIPT_NAME']}?src_url=&generate_enclosure=<0|1>"); - else +/** + * 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] \n"; + } + else { + $usage = htmlentities("{$_SERVER['SCRIPT_NAME']}?src_url=&generate_enclosure=<0|1>"); + } return "usage: $usage"; } -function parse_options_cli($argv, $argc) -{ +/** + * Parse command line options. + */ +function parse_options_cli($argv, $argc) { $options = array( - 'generate_enclosure' => FALSE + 'generate_enclosure' => FALSE, ); - if ($argc < 2) + 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: - die(usage($argv)); + case 'e': + $options['generate_enclosure'] = TRUE; + break; + + case 'h': + case 'help': + echo usage($argv); + exit(0); + + default: + fwrite(STDERR, usage($argv)); + exit(1); } } @@ -176,37 +408,42 @@ function parse_options_cli($argv, $argc) return $options; } -function parse_options_query_string() -{ +/** + * Parse options passed from a query string. + */ +function parse_options_query_string() { $options = array( - 'generate_enclosure' => FALSE + 'generate_enclosure' => FALSE, ); - if (isset($_GET['src_url'])) + if (isset($_GET['src_url'])) { $options['src_url'] = $_GET['src_url']; + } - if (isset($_GET['generate_enclosure'])) + if (isset($_GET['generate_enclosure'])) { $options['generate_enclosure'] = $_GET['generate_enclosure'] == 1; + } return $options; } - -if (php_sapi_name() != 'cli') - $options = parse_options_query_string(); -else +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'])) - die(usage($argv)); - -$url = parse_url($options['src_url']); -if (FALSE === $url || empty($url["host"])) - die("Invalid url: ${options['src_url']}\n"); - -$stylesheet = __DIR__ . "/rss_converter_" . $url["host"] . ".xsl"; -if (FALSE === file_exists($stylesheet)) - die("Conversion to RSS not supported: {$url["host"]}\n"); +if (!isset($options['src_url'])) { + fwrite($error_stream, usage(is_cli() ? $argv : NULL)); + exit(1); +} -$tweeper = new Tweeper($stylesheet, $options['generate_enclosure']); -echo $tweeper->tweep($options['src_url']); +$tweeper = new Tweeper($options['generate_enclosure']); +$output = $tweeper->tweep($options['src_url']); +if (is_null($output)) { + exit(1); +} +echo $output;