X-Git-Url: https://git.ao2.it/tweeper.git/blobdiff_plain/c3e332f73ac7c6119459c78d109af697e7c4721b..77e6cd315b5c270104a1116102d0296cf3e6495b:/src/Tweeper.php

diff --git a/src/Tweeper.php b/src/Tweeper.php
index 566decb..09bd7cc 100644
--- a/src/Tweeper.php
+++ b/src/Tweeper.php
@@ -6,7 +6,7 @@ namespace Tweeper;
  * @file
  * Tweeper - a Twitter to RSS web scraper.
  *
- * Copyright (C) 2013-2016  Antonio Ospite <ao2@ao2.it>
+ * Copyright (C) 2013-2018  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
@@ -36,13 +36,28 @@ date_default_timezone_set('UTC');
  */
 class Tweeper {
 
-  private static $userAgent = "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; WOW64; rv:60.0) Gecko/20100101 Firefox/60.0";
+  private static $maxConnectionTimeout = 5;
+  private static $maxConnectionRetries = 5;
 
   /**
-   * Constructor sets up {@link $generate_enclosure}.
+   * Create a new Tweeper object controlling optional settings.
+   *
+   * @param bool $generate_enclosure
+   *   Enables the creation of <enclosure/> elements (disabled by default).
+   * @param bool $show_usernames
+   *   Enables showing the username in front of the content for multi-user
+   *   sites (enabled by default). Only some stylesheets supports this
+   *   functionality (twitter, instagram, pump.io).
+   * @param bool $show_multimedia
+   *   Enables showing multimedia content (images, videos) directly in the
+   *   item description (enabled by default). Only some stylesheets supports
+   *   this functionality (twitter, instagram, dilbert).
    */
-  public function __construct($generate_enclosure = FALSE) {
+  public function __construct($generate_enclosure = FALSE, $show_usernames = TRUE, $show_multimedia = TRUE) {
     $this->generate_enclosure = $generate_enclosure;
+    $this->show_usernames = $show_usernames;
+    $this->show_multimedia = $show_multimedia;
   }
 
   /**
@@ -78,12 +93,32 @@ class Tweeper {
   }
 
   /**
+   * Perform a cURL session multiple times when it fails with a timeout.
+   *
+   * @param resource $ch
+   *   a cURL session handle.
+   */
+  private static function curlExec($ch) {
+    $ret = FALSE;
+    $attempt = 0;
+    do {
+      $ret = curl_exec($ch);
+      if (FALSE === $ret) {
+        trigger_error(curl_error($ch), E_USER_WARNING);
+      }
+    } while (curl_errno($ch) == CURLE_OPERATION_TIMEDOUT && ++$attempt < Tweeper::$maxConnectionRetries);
+
+    return $ret;
+  }
+
+  /**
    * Get the contents from a URL.
    */
   private static function getUrlContents($url) {
     $ch = curl_init($url);
     curl_setopt_array($ch, array(
       CURLOPT_HEADER => FALSE,
+      CURLOPT_CONNECTTIMEOUT => Tweeper::$maxConnectionTimeout,
       // Follow http redirects to get the real URL.
       CURLOPT_FOLLOWLOCATION => TRUE,
       CURLOPT_RETURNTRANSFER => TRUE,
@@ -92,10 +127,7 @@ class Tweeper {
       CURLOPT_HTTPHEADER => array('Accept-language: en'),
       CURLOPT_USERAGENT => Tweeper::$userAgent,
     ));
-    $contents = curl_exec($ch);
-    if (FALSE === $contents) {
-      trigger_error(curl_error($ch));
-    }
+    $contents = Tweeper::curlExec($ch);
     curl_close($ch);
 
     return $contents;
@@ -109,6 +141,7 @@ class Tweeper {
     curl_setopt_array($ch, array(
       CURLOPT_HEADER => TRUE,
       CURLOPT_NOBODY => TRUE,
+      CURLOPT_CONNECTTIMEOUT => Tweeper::$maxConnectionTimeout,
       // Follow http redirects to get the real URL.
       CURLOPT_FOLLOWLOCATION => TRUE,
       CURLOPT_RETURNTRANSFER => TRUE,
@@ -116,10 +149,16 @@ class Tweeper {
       CURLOPT_SSL_VERIFYPEER => FALSE,
       CURLOPT_USERAGENT => Tweeper::$userAgent,
     ));
-    curl_exec($ch);
+
+    $ret = Tweeper::curlExec($ch);
+    if (FALSE === $ret) {
+      curl_close($ch);
+      return FALSE;
+    }
+
     $url_info = curl_getinfo($ch);
     if (FALSE === $url_info) {
-      trigger_error(curl_error($ch));
+      trigger_error(curl_error($ch), E_USER_WARNING);
     }
     curl_close($ch);
 
@@ -152,10 +191,14 @@ class Tweeper {
     );
 
     $url_info = Tweeper::getUrlInfo($url);
+    if (FALSE === $url_info) {
+      trigger_error("Failed to retrieve info for URL: " . $url, E_USER_WARNING);
+      return '';
+    }
 
     $supported = in_array($url_info['content_type'], $supported_content_types);
     if (!$supported) {
-      error_log("Unsupported enclosure content type \"" . $url_info['content_type'] . "\" for URL: " . $url_info['url']);
+      trigger_error("Unsupported enclosure content type \"" . $url_info['content_type'] . "\" for URL: " . $url_info['url'], E_USER_WARNING);
       return '';
     }
 
@@ -163,10 +206,17 @@ class Tweeper {
     // See http://sourceforge.net/p/feedvalidator/bugs/72/
     $http_url = preg_replace("/^https/", "http", $url_info['url']);
 
+    // When the server does not provide a Content-Length header,
+    // curl_getinfo() would return a negative value for
+    // "download_content_length", however RSS recommends to use 0 when the
+    // enclosure's size cannot be determined.
+    // See: https://www.feedvalidator.org/docs/error/UseZeroForUnknown.html
+    $length = max($url_info['download_content_length'], 0);
+
     $dom = new DOMDocument();
     $enc = $dom->createElement('enclosure');
     $enc->setAttribute('url', $http_url);
-    $enc->setAttribute('length', $url_info['download_content_length']);
+    $enc->setAttribute('length', $length);
     $enc->setAttribute('type', $url_info['content_type']);
 
     return $enc;
@@ -203,7 +253,7 @@ class Tweeper {
 
     $output .= " line $error->line";
 
-    error_log($output);
+    trigger_error($output, E_USER_WARNING);
   }
 
   /**
@@ -230,7 +280,7 @@ class Tweeper {
 
     $xml_data = $serializer->serialize($data, 'xml', $serializer_options);
     if (!$xml_data) {
-      trigger_error("Cannot serialize data", E_USER_ERROR);
+      trigger_error("Cannot serialize data", E_USER_WARNING);
       return NULL;
     }
 
@@ -245,14 +295,20 @@ class Tweeper {
     $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);
+      trigger_error("Cannot match expression: $json_match_expr\n", E_USER_WARNING);
       return NULL;
     }
 
+    $data = json_decode($matches[1], $assoc = TRUE);
+
     // The "qe" object contains elements which will result in invalid XML
     // element names, so remove it.
-    $data = json_decode($matches[1], $assoc = TRUE);
     unset($data["qe"]);
+
+    // The "knobs" object contains elements with undefined namespaces, so
+    // remove it to silence an error message.
+    unset($data["knobs"]);
+
     $json = json_encode($data);
 
     return Tweeper::jsonToXml($json, 'instagram');
@@ -301,11 +357,15 @@ class Tweeper {
   private function loadStylesheet($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);
+      trigger_error("Conversion to RSS not supported for $host ($stylesheet not found)", E_USER_WARNING);
       return NULL;
     }
 
     $stylesheet_contents = Tweeper::getUrlContents($stylesheet);
+    if (FALSE === $stylesheet_contents) {
+      trigger_error("Cannot open $stylesheet", E_USER_WARNING);
+      return NULL;
+    }
 
     $xslDoc = new DOMDocument();
     $xslDoc->loadXML($stylesheet_contents);
@@ -313,6 +373,8 @@ class Tweeper {
     $xsltProcessor = new XSLTProcessor();
     $xsltProcessor->registerPHPFunctions();
     $xsltProcessor->setParameter('', 'generate-enclosure', $this->generate_enclosure);
+    $xsltProcessor->setParameter('', 'show-usernames', $this->show_usernames);
+    $xsltProcessor->setParameter('', 'show-multimedia', $this->show_multimedia);
     $xsltProcessor->importStylesheet($xslDoc);
 
     return $xsltProcessor;
@@ -321,25 +383,25 @@ class Tweeper {
   /**
    * Convert the site content to RSS.
    */
-  public function tweep($src_url, $host=NULL, $validate_scheme=TRUE) {
+  public function tweep($src_url, $host = NULL, $validate_scheme = TRUE) {
     $url = parse_url($src_url);
     if (FALSE === $url) {
-      trigger_error("Invalid URL: $src_url", E_USER_ERROR);
+      trigger_error("Invalid URL: $src_url", E_USER_WARNING);
       return NULL;
     }
 
     if (TRUE === $validate_scheme) {
       $scheme = $url["scheme"];
       if (!in_array($scheme, array("http", "https"))) {
-        trigger_error("unsupported scheme: $scheme", E_USER_ERROR);
+        trigger_error("unsupported scheme: $scheme", E_USER_WARNING);
         return NULL;
       }
     }
 
-    // if the host is not given derive it from the URL
+    // If the host is not given derive it from the URL.
     if (NULL === $host) {
       if (empty($url["host"])) {
-        trigger_error("Invalid host in URL: $src_url", E_USER_ERROR);
+        trigger_error("Invalid host in URL: $src_url", E_USER_WARNING);
         return NULL;
       }
       // Strip the leading www. to be more forgiving on input URLs.
@@ -353,6 +415,7 @@ class Tweeper {
 
     $html = Tweeper::getUrlContents($src_url);
     if (FALSE === $html) {
+      trigger_error("Failed to retrieve $src_url", E_USER_WARNING);
       return NULL;
     }
 
@@ -367,11 +430,11 @@ class Tweeper {
     }
 
     $output = $xsltProcessor->transformToXML($xmlDoc);
-
     if (FALSE === $output) {
-      trigger_error('XSL transformation failed.', E_USER_ERROR);
+      trigger_error('XSL transformation failed.', E_USER_WARNING);
       return NULL;
     }
+
     return $output;
   }