inc/3rdparty/content-extractor/SiteConfig.php

   1 <?php
   2 /**
   3  * Site Config
   4  *
   5  * Each instance of this class should hold extraction patterns and other directives
   6  * for a website. See ContentExtractor class to see how it's used.
   7  *
   8  * @version 0.6
   9  * @date 2011-10-30
  10  * @author Keyvan Minoukadeh
  11  * @copyright 2011 Keyvan Minoukadeh
  12  * @license http://www.gnu.org/licenses/agpl-3.0.html AGPL v3
  13  */
  14
  15 class SiteConfig
  16 {
  17         // Use first matching element as title (0 or more xpath expressions)
  18         public $title = array();
  19
  20         // Use first matching element as body (0 or more xpath expressions)
  21         public $body = array();
  22
  23         // Use first matching element as author (0 or more xpath expressions)
  24         public $author = array();
  25
  26         // Use first matching element as date (0 or more xpath expressions)
  27         public $date = array();
  28
  29         // Strip elements matching these xpath expressions (0 or more)
  30         public $strip = array();
  31
  32         // Strip elements which contain these strings (0 or more) in the id or class attribute
  33         public $strip_id_or_class = array();
  34
  35         // Strip images which contain these strings (0 or more) in the src attribute
  36         public $strip_image_src = array();
  37
  38         // Additional HTTP headers to send
  39         // NOT YET USED
  40         public $http_header = array();
  41
  42         // Process HTML with tidy before creating DOM
  43         public $tidy = true;
  44
  45         // Autodetect title/body if xpath expressions fail to produce results.
  46         // Note that this applies to title and body separately, ie.
  47         //   * if we get a body match but no title match, this option will determine whether we autodetect title
  48         //   * if neither match, this determines whether we autodetect title and body.
  49         // Also note that this only applies when there is at least one xpath expression in title or body, ie.
  50         //   * if title and body are both empty (no xpath expressions), this option has no effect (both title and body will be auto-detected)
  51         //   * if there's an xpath expression for title and none for body, body will be auto-detected and this option will determine whether we auto-detect title if the xpath expression for it fails to produce results.
  52         // Usage scenario: you want to extract something specific from a set of URLs, e.g. a table, and if the table is not found, you want to ignore the entry completely. Auto-detection is unlikely to succeed here, so you construct your patterns and set this option to false. Another scenario may be a site where auto-detection has proven to fail (or worse, picked up the wrong content).
  53         public $autodetect_on_failure = true;
  54
  55         // Clean up content block - attempt to remove elements that appear to be superfluous
  56         public $prune = true;
  57
  58         // Test URL - if present, can be used to test the config above
  59         public $test_url = null;
  60
  61         // Single-page link - should identify a link element or URL pointing to the page holding the entire article
  62         // This is useful for sites which split their articles across multiple pages. Links to such pages tend to
  63         // display the first page with links to the other pages at the bottom. Often there is also a link to a page
  64         // which displays the entire article on one page (e.g. 'print view').
  65         // This should be an XPath expression identifying the link to that page. If present and we find a match,
  66         // we will retrieve that page and the rest of the options in this config will be applied to the new page.
  67         public $single_page_link = array();
  68
  69         // Single-page link in feed? - same as above, but patterns applied to item description HTML taken from feed
  70         public $single_page_link_in_feed = array();
  71
  72         // TODO: which parser to use for turning raw HTML into a DOMDocument
  73         public $parser = 'libxml';
  74
  75         // String replacement to be made on HTML before processing begins
  76         public $replace_string = array();
  77
  78         // the options below cannot be set in the config files which this class represents
  79
  80         public static $debug = false;
  81         protected static $config_path;
  82         protected static $config_path_fallback;
  83         protected static $config_cache = array();
  84         const HOSTNAME_REGEX = '/^(([a-zA-Z0-9-]*[a-zA-Z0-9])\.)*([A-Za-z0-9-]*[A-Za-z0-9])$/';
  85
  86         protected static function debug($msg) {
  87                 if (self::$debug) {
  88                         $mem = round(memory_get_usage()/1024, 2);
  89                         $memPeak = round(memory_get_peak_usage()/1024, 2);
  90                         echo '* ',$msg;
  91                         echo ' - mem used: ',$mem," (peak: $memPeak)\n";
  92                         ob_flush();
  93                         flush();
  94                 }
  95         }
  96
  97         public static function set_config_path($path, $fallback=null) {
  98                 self::$config_path = $path;
  99                 self::$config_path_fallback = $fallback;
 100         }
 101
 102         public static function add_to_cache($host, SiteConfig $config) {
 103                 $host = strtolower($host);
 104                 self::$config_cache[$host] = $config;
 105         }
 106
 107         // returns SiteConfig instance if an appropriate one is found, false otherwise
 108         public static function build($host) {
 109                 $host = strtolower($host);
 110                 if (substr($host, 0, 4) == 'www.') $host = substr($host, 4);
 111                 if (!$host || (strlen($host) > 200) || !preg_match(self::HOSTNAME_REGEX, $host)) return false;
 112                 // check for site configuration
 113                 $try = array($host);
 114                 $split = explode('.', $host);
 115                 if (count($split) > 1) {
 116                         array_shift($split);
 117                         $try[] = '.'.implode('.', $split);
 118                 }
 119                 foreach ($try as $h) {
 120                         if (array_key_exists($h, self::$config_cache)) {
 121                                 self::debug("... cached ($h)");
 122                                 return self::$config_cache[$h];
 123                         } elseif (file_exists(self::$config_path."/$h.txt")) {
 124                                 self::debug("... from file ($h)");
 125                                 $file = self::$config_path."/$h.txt";
 126                                 break;
 127                         }
 128                 }
 129                 if (!isset($file)) {
 130                         if (isset(self::$config_path_fallback)) {
 131                                 self::debug("... trying fallback ($host)");
 132                                 foreach ($try as $h) {
 133                                         if (file_exists(self::$config_path_fallback."/$h.txt")) {
 134                                                 self::debug("... from fallback file ($h)");
 135                                                 $file = self::$config_path_fallback."/$h.txt";
 136                                                 break;
 137                                         }
 138                                 }
 139                                 if (!isset($file)) {
 140                                         self::debug("... no match in fallback directory");
 141                                         return false;
 142                                 }
 143                         } else {
 144                                 self::debug("... no match ($host)");
 145                                 return false;
 146                         }
 147                 }
 148                 $config_file = file($file, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
 149                 if (!$config_file || !is_array($config_file)) return false;
 150                 $config = new SiteConfig();
 151                 foreach ($config_file as $line) {
 152                         $line = trim($line);
 153
 154                         // skip comments, empty lines
 155                         if ($line == '' || $line[0] == '#') continue;
 156
 157                         // get command
 158                         $command = explode(':', $line, 2);
 159                         // if there's no colon ':', skip this line
 160                         if (count($command) != 2) continue;
 161                         $val = trim($command[1]);
 162                         $command = trim($command[0]);
 163                         if ($command == '' || $val == '') continue;
 164
 165                         // check for commands where we accept multiple statements
 166                         if (in_array($command, array('title', 'body', 'author', 'date', 'strip', 'strip_id_or_class', 'strip_image_src', 'single_page_link', 'single_page_link_in_feed', 'http_header'))) {
 167                                 array_push($config->$command, $val);
 168                         // check for single statement commands that evaluate to true or false
 169                         } elseif (in_array($command, array('tidy', 'prune', 'autodetect_on_failure'))) {
 170                                 $config->$command = ($val == 'yes');
 171                         // check for single statement commands stored as strings
 172                         } elseif (in_array($command, array('test_url', 'parser'))) {
 173                                 $config->$command = $val;
 174                         } elseif ((substr($command, -1) == ')') && preg_match('!^([a-z0-9_]+)\((.*?)\)$!i', $command, $match)) {
 175                                 if (in_array($match[1], array('replace_string'))) {
 176                                         $command = $match[1];
 177                                         array_push($config->$command, array($match[2], $val));
 178                                 }
 179                         }
 180                 }
 181                 return $config;
 182         }
 183 }
 184 ?>