README: describe what tweeper is in a more generic way

[tweeper.git] / tweeper.php

diff --git a/tweeper.php b/tweeper.php
index d084398..a9fce9b 100644 (file)
--- a/tweeper.php
+++ b/tweeper.php
@@ -18,6 +18,8 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+require_once 'XML/Serializer.php';
+
 date_default_timezone_set('UTC');
 
 class Tweeper {
@@ -30,12 +32,20 @@ class Tweeper {
 
   public static function epoch_to_gmdate($timestamp)
   {
+    if (!is_numeric($timestamp) || is_nan($timestamp)) {
+      $timestamp = 0;
+    }
+
     return gmdate('D, d M Y H:i:s', $timestamp) . ' GMT';
   }
 
   public static function str_to_gmdate($date)
   {
     $timestamp = strtotime($date);
+    if (FALSE === $timestamp) {
+      $timestamp = 0;
+    }
+
     return Tweeper::epoch_to_gmdate($timestamp);
   }
 
@@ -151,7 +161,7 @@ class Tweeper {
   private function load_stylesheet($host) {
     $stylesheet = "file://" . __DIR__ . "/rss_converter_" . $host . ".xsl";
     if (FALSE === file_exists($stylesheet)) {
-      trigger_error("Conversion to RSS not supported: $host", E_USER_ERROR);
+      trigger_error("Conversion to RSS not supported for $host ($stylesheet not found)", E_USER_ERROR);
       return NULL;
     }
 
@@ -168,12 +178,62 @@ class Tweeper {
     return $xsltProcessor;
   }
 
-  private function html_to_xml($html) {
+  private function json_to_xml($html, $json_match_expr, $rootName) {
+    // pre-process, convert json to XML
+    $ret = preg_match($json_match_expr, $html, $matches);
+    if ($ret !== 1) {
+      trigger_error("Cannot match expression: $json_match_expr\n", E_USER_ERROR);
+      return NULL;
+    }
+
+    $data = json_decode($matches[1]);
+    if (!$data) {
+      return NULL;
+    }
+
+    $serializer_options = array (
+      'addDecl' => TRUE,
+      'encoding' => "UTF-8",
+      'indent' => '  ',
+      'rootName' => $rootName,
+    );
+
+    $serializer = new XML_Serializer($serializer_options);
+
+    $status = $serializer->serialize($data);
+    if (PEAR::isError($status)) {
+      trigger_error($status->getMessage(), E_USER_ERROR);
+      return NULL;
+    }
+
+    return $serializer->getSerializedData();
+  }
+
+  private function get_xml_instagram_com($html) {
+    return $this->json_to_xml($html, '/window._sharedData = (.*);/', 'instagram');
+  }
+
+  private function preprocess_html_facebook_com($html) {
+    $html = str_replace('<!--', '', $html);
+    $html = str_replace('-->', '', $html);
+    return $html;
+  }
+
+  private function html_to_xml($html, $host) {
     $xmlDoc = new DOMDocument();
 
     // Handle warnings and errors when loading invalid HTML.
     $xml_errors_value = libxml_use_internal_errors(true);
-    $xmlDoc->loadHTML($html);
+
+    // If there is a host-specific method to get the xml data, use it!
+    $get_xml_host_method = 'get_xml_' . str_replace(".", "_", $host);
+    if (method_exists($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) {
       $this->log_xml_error($xml_error);
     }
@@ -190,7 +250,10 @@ class Tweeper {
       return NULL;
     }
 
-    $xsltProcessor = $this->load_stylesheet($url["host"]);
+    // Strip the leading www. to be more forgiving on input URLs
+    $host = preg_replace('/^www\./', '', $url["host"]);
+
+    $xsltProcessor = $this->load_stylesheet($host);
     if (NULL === $xsltProcessor) {
       return NULL;
     }
@@ -200,7 +263,12 @@ class Tweeper {
       return NULL;
     }
 
-    $xmlDoc = $this->html_to_xml($html);
+    $preprocess_html_host_method = 'preprocess_html_' . str_replace(".", "_", $host);
+    if (method_exists($this, $preprocess_html_host_method)) {
+      $html = call_user_func_array(array($this, $preprocess_html_host_method), array($html));
+    }
+
+    $xmlDoc = $this->html_to_xml($html, $host);
     if (NULL === $xmlDoc) {
       return NULL;
     }
@@ -215,12 +283,18 @@ class Tweeper {
   }
 }
 
+function is_cli()
+{
+  return (php_sapi_name() === "cli");
+}
+
 function usage($argv)
 {
-  if (php_sapi_name() != 'cli')
-    $usage = htmlentities("{$_SERVER['SCRIPT_NAME']}?src_url=<src_url>&generate_enclosure=<0|1>");
-  else
+  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";
 }
@@ -271,16 +345,16 @@ function parse_options_query_string()
 }
 
 
-if (php_sapi_name() != 'cli') {
-  $options = parse_options_query_string();
-  $ERROR_STREAM = fopen('php://output', 'w');
-} 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($options['src_url'])) {
-  fwrite($ERROR_STREAM, usage($argv));
+  fwrite($ERROR_STREAM, usage(is_cli() ? $argv : NULL));
   exit(1);
 }