Add option to enable or disable showing verbose output

[tweeper.git] / src / Tweeper.php

diff --git a/src/Tweeper.php b/src/Tweeper.php
index 7318900..e98623b 100644 (file)
--- a/src/Tweeper.php
+++ b/src/Tweeper.php
@@ -36,7 +36,9 @@ date_default_timezone_set('UTC');
  */
 class Tweeper {
 
-  private static $userAgent = "Mozilla/5.0 (Windows NT 6.1; WOW64; rv:60.0) Gecko/20100101 Firefox/60.0";
+  private static $userAgent = "Mozilla/5.0";
+  private static $maxConnectionTimeout = 5;
+  private static $maxConnectionRetries = 5;
 
   /**
    * Create a new Tweeper object controlling optional settings.
@@ -47,10 +49,18 @@ class Tweeper {
    *   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).
+   * @param bool $verbose_output
+   *   Enables showing non-fatal errors like XML parsing errors.
    */
-  public function __construct($generate_enclosure = FALSE, $show_usernames = TRUE) {
+  public function __construct($generate_enclosure = FALSE, $show_usernames = TRUE, $show_multimedia = TRUE, $verbose_output = TRUE) {
     $this->generate_enclosure = $generate_enclosure;
     $this->show_usernames = $show_usernames;
+    $this->show_multimedia = $show_multimedia;
+    $this->verbose_output = $verbose_output;
   }
 
   /**
@@ -86,24 +96,40 @@ 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_COOKIEFILE => "",
       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), E_USER_WARNING);
-    }
+    $contents = Tweeper::curlExec($ch);
     curl_close($ch);
 
     return $contents;
@@ -117,17 +143,15 @@ class Tweeper {
     curl_setopt_array($ch, array(
       CURLOPT_HEADER => TRUE,
       CURLOPT_NOBODY => TRUE,
+      CURLOPT_CONNECTTIMEOUT => Tweeper::$maxConnectionTimeout,
       // Follow http redirects to get the real URL.
       CURLOPT_FOLLOWLOCATION => TRUE,
       CURLOPT_RETURNTRANSFER => TRUE,
-      CURLOPT_SSL_VERIFYHOST => FALSE,
-      CURLOPT_SSL_VERIFYPEER => FALSE,
       CURLOPT_USERAGENT => Tweeper::$userAgent,
     ));
 
-    $ret = curl_exec($ch);
+    $ret = Tweeper::curlExec($ch);
     if (FALSE === $ret) {
-      trigger_error(curl_error($ch), E_USER_WARNING);
       curl_close($ch);
       return FALSE;
     }
@@ -182,10 +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;
@@ -311,8 +342,10 @@ class Tweeper {
       $xmlDoc->loadHTML($html);
     }
 
-    foreach (libxml_get_errors() as $xml_error) {
-      Tweeper::logXmlError($xml_error);
+    if ($this->verbose_output) {
+      foreach (libxml_get_errors() as $xml_error) {
+        Tweeper::logXmlError($xml_error);
+      }
     }
     libxml_clear_errors();
     libxml_use_internal_errors($xml_errors_value);
@@ -332,6 +365,7 @@ class Tweeper {
 
     $stylesheet_contents = Tweeper::getUrlContents($stylesheet);
     if (FALSE === $stylesheet_contents) {
+      trigger_error("Cannot open $stylesheet", E_USER_WARNING);
       return NULL;
     }
 
@@ -342,6 +376,7 @@ class Tweeper {
     $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 $xsltProcessor;
@@ -350,7 +385,7 @@ class Tweeper {
   /**
    * Convert the site content to RSS.
    */
-  public function tweep($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_WARNING);
@@ -365,7 +400,7 @@ class Tweeper {
       }
     }
 
-    // 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_WARNING);
@@ -382,6 +417,7 @@ class Tweeper {
 
     $html = Tweeper::getUrlContents($src_url);
     if (FALSE === $html) {
+      trigger_error("Failed to retrieve $src_url", E_USER_WARNING);
       return NULL;
     }