inc/3rdparty/libraries/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 0.7
   9  * @date 2012-08-27
  10  * @author Keyvan Minoukadeh
  11  * @copyright 2012 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 (bool or null if undeclared)
  43         public $tidy = null;
  44
  45         protected $default_tidy = true; // used if undeclared
  46
  47         // Autodetect title/body if xpath expressions fail to produce results.
  48         // Note that this applies to title and body separately, ie.
  49         //   * if we get a body match but no title match, this option will determine whether we autodetect title
  50         //   * if neither match, this determines whether we autodetect title and body.
  51         // Also note that this only applies when there is at least one xpath expression in title or body, ie.
  52         //   * if title and body are both empty (no xpath expressions), this option has no effect (both title and body will be auto-detected)
  53         //   * 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.
  54         // 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).
  55         // bool or null if undeclared
  56         public $autodetect_on_failure = null;
  57         protected $default_autodetect_on_failure = true; // used if undeclared
  58
  59         // Clean up content block - attempt to remove elements that appear to be superfluous
  60         // bool or null if undeclared
  61         public $prune = null;
  62         protected $default_prune = true; // used if undeclared
  63
  64         // Test URL - if present, can be used to test the config above
  65         public $test_url = array();
  66
  67         // Single-page link - should identify a link element or URL pointing to the page holding the entire article
  68         // This is useful for sites which split their articles across multiple pages. Links to such pages tend to
  69         // display the first page with links to the other pages at the bottom. Often there is also a link to a page
  70         // which displays the entire article on one page (e.g. 'print view').
  71         // This should be an XPath expression identifying the link to that page. If present and we find a match,
  72         // we will retrieve that page and the rest of the options in this config will be applied to the new page.
  73         public $single_page_link = array();
  74
  75         public $next_page_link = array();
  76
  77         // Single-page link in feed? - same as above, but patterns applied to item description HTML taken from feed
  78         public $single_page_link_in_feed = array();
  79
  80         // Which parser to use for turning raw HTML into a DOMDocument (either 'libxml' or 'html5lib')
  81         // string or null if undeclared
  82         public $parser = null;
  83         protected $default_parser = 'libxml'; // used if undeclared
  84
  85         // Strings to search for in HTML before processing begins (used with $replace_string)
  86         public $find_string = array();
  87         // Strings to replace those found in $find_string before HTML processing begins
  88         public $replace_string = array();
  89
  90         // the options below cannot be set in the config files which this class represents
  91
  92         //public $cache_in_apc = false; // used to decide if we should cache in apc or not
  93         public $cache_key = null;
  94         public static $debug = false;
  95         protected static $apc = false;
  96         protected static $config_path;
  97         protected static $config_path_fallback;
  98         protected static $config_cache = array();
  99         const HOSTNAME_REGEX = '/^(([a-zA-Z0-9-]*[a-zA-Z0-9])\.)*([A-Za-z0-9-]*[A-Za-z0-9])$/';
 100
 101         protected static function debug($msg) {
 102                 if (self::$debug) {
 103                         //$mem = round(memory_get_usage()/1024, 2);
 104                         //$memPeak = round(memory_get_peak_usage()/1024, 2);
 105                         echo '* ',$msg;
 106                         //echo ' - mem used: ',$mem," (peak: $memPeak)\n";
 107                         echo "\n";
 108                         ob_flush();
 109                         flush();
 110                 }
 111         }
 112
 113         // enable APC caching of certain site config files?
 114         // If enabled the following site config files will be
 115         // cached in APC cache (when requested for first time):
 116         // * anything in site_config/custom/ and its corresponding file in site_config/standard/
 117         // * the site config files associated with HTML fingerprints
 118         // * the global site config file
 119         // returns true if enabled, false otherwise
 120         public static function use_apc($apc=true) {
 121                 if (!function_exists('apc_add')) {
 122                         if ($apc) self::debug('APC will not be used (function apc_add does not exist)');
 123                         return false;
 124                 }
 125                 self::$apc = $apc;
 126                 return $apc;
 127         }
 128
 129         // return bool or null
 130         public function tidy($use_default=true) {
 131                 if ($use_default) return (isset($this->tidy)) ? $this->tidy : $this->default_tidy;
 132                 return $this->tidy;
 133         }
 134
 135         // return bool or null
 136         public function prune($use_default=true) {
 137                 if ($use_default) return (isset($this->prune)) ? $this->prune : $this->default_prune;
 138                 return $this->prune;
 139         }
 140
 141         // return string or null
 142         public function parser($use_default=true) {
 143                 if ($use_default) return (isset($this->parser)) ? $this->parser : $this->default_parser;
 144                 return $this->parser;
 145         }
 146
 147         // return bool or null
 148         public function autodetect_on_failure($use_default=true) {
 149                 if ($use_default) return (isset($this->autodetect_on_failure)) ? $this->autodetect_on_failure : $this->default_autodetect_on_failure;
 150                 return $this->autodetect_on_failure;
 151         }
 152
 153         public static function set_config_path($path, $fallback=null) {
 154                 self::$config_path = $path;
 155                 self::$config_path_fallback = $fallback;
 156         }
 157
 158         public static function add_to_cache($key, SiteConfig $config, $use_apc=true) {
 159                 $key = strtolower($key);
 160                 if (substr($key, 0, 4) == 'www.') $key = substr($key, 4);
 161                 if ($config->cache_key) $key = $config->cache_key;
 162                 self::$config_cache[$key] = $config;
 163                 if (self::$apc && $use_apc) {
 164                         self::debug("Adding site config to APC cache with key sc.$key");
 165                         apc_add("sc.$key", $config);
 166                 }
 167                 self::debug("Cached site config with key $key");
 168         }
 169
 170         public static function is_cached($key) {
 171                 $key = strtolower($key);
 172                 if (substr($key, 0, 4) == 'www.') $key = substr($key, 4);
 173                 if (array_key_exists($key, self::$config_cache)) {
 174                         return true;
 175                 } elseif (self::$apc && (bool)apc_fetch("sc.$key")) {
 176                         return true;
 177                 }
 178                 return false;
 179         }
 180
 181         public function append(SiteConfig $newconfig) {
 182                 // check for commands where we accept multiple statements (no test_url)
 183                 foreach (array('title', 'body', 'author', 'date', 'strip', 'strip_id_or_class', 'strip_image_src', 'single_page_link', 'single_page_link_in_feed', 'next_page_link', 'http_header', 'find_string', 'replace_string') as $var) {
 184                         // append array elements for this config variable from $newconfig to this config
 185                         //$this->$var = $this->$var + $newconfig->$var;
 186                         $this->$var = array_unique(array_merge($this->$var, $newconfig->$var));
 187                 }
 188                 // check for single statement commands
 189                 // we do not overwrite existing non null values
 190                 foreach (array('tidy', 'prune', 'parser', 'autodetect_on_failure') as $var) {
 191                         if ($this->$var === null) $this->$var = $newconfig->$var;
 192                 }
 193         }
 194
 195         // returns SiteConfig instance if an appropriate one is found, false otherwise
 196         // if $exact_host_match is true, we will not look for wildcard config matches
 197         // by default if host is 'test.example.org' we will look for and load '.example.org.txt' if it exists
 198         public static function build($host, $exact_host_match=false) {
 199                 $host = strtolower($host);
 200                 if (substr($host, 0, 4) == 'www.') $host = substr($host, 4);
 201                 if (!$host || (strlen($host) > 200) || !preg_match(self::HOSTNAME_REGEX, ltrim($host, '.'))) return false;
 202                 // check for site configuration
 203                 $try = array($host);
 204                 // should we look for wildcard matches
 205                 if (!$exact_host_match) {
 206                         $split = explode('.', $host);
 207                         if (count($split) > 1) {
 208                                 array_shift($split);
 209                                 $try[] = '.'.implode('.', $split);
 210                         }
 211                 }
 212
 213                 // look for site config file in primary folder
 214                 self::debug(". looking for site config for $host in primary folder");
 215                 foreach ($try as $h) {
 216                         if (array_key_exists($h, self::$config_cache)) {
 217                                 self::debug("... site config for $h already loaded in this request");
 218                                 return self::$config_cache[$h];
 219                         } elseif (self::$apc && ($sconfig = apc_fetch("sc.$h"))) {
 220                                 self::debug("... site config for $h in APC cache");
 221                                 return $sconfig;
 222                         } elseif (file_exists(self::$config_path."/$h.txt")) {
 223                                 self::debug("... found site config ($h.txt)");
 224                                 $file_primary = self::$config_path."/$h.txt";
 225                                 $matched_name = $h;
 226                                 break;
 227                         }
 228                 }
 229
 230                 // if we found site config, process it
 231                 if (isset($file_primary)) {
 232                         $config_lines = file($file_primary, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
 233                         if (!$config_lines || !is_array($config_lines)) return false;
 234                         $config = self::build_from_array($config_lines);
 235                         // if APC caching is available and enabled, mark this for cache
 236                         //$config->cache_in_apc = true;
 237                         $config->cache_key = $matched_name;
 238
 239                         // if autodetec on failure is off (on by default) we do not need to look
 240                         // in secondary folder
 241                         if (!$config->autodetect_on_failure()) {
 242                                 self::debug('... autodetect on failure is disabled (no other site config files will be loaded)');
 243                                 return $config;
 244                         }
 245                 }
 246
 247                 // look for site config file in secondary folder
 248                 if (isset(self::$config_path_fallback)) {
 249                         self::debug(". looking for site config for $host in secondary folder");
 250                         foreach ($try as $h) {
 251                                 if (file_exists(self::$config_path_fallback."/$h.txt")) {
 252                                         self::debug("... found site config in secondary folder ($h.txt)");
 253                                         $file_secondary = self::$config_path_fallback."/$h.txt";
 254                                         $matched_name = $h;
 255                                         break;
 256                                 }
 257                         }
 258                         if (!isset($file_secondary)) {
 259                                 self::debug("... no site config match in secondary folder");
 260                         }
 261                 }
 262
 263                 // return false if no config file found
 264                 if (!isset($file_primary) && !isset($file_secondary)) {
 265                         self::debug("... no site config match for $host");
 266                         return false;
 267                 }
 268
 269                 // return primary config if secondary not found
 270                 if (!isset($file_secondary) && isset($config)) {
 271                         return $config;
 272                 }
 273
 274                 // process secondary config file
 275                 $config_lines = file($file_secondary, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
 276                 if (!$config_lines || !is_array($config_lines)) {
 277                         // failed to process secondary
 278                         if (isset($config)) {
 279                                 // return primary config
 280                                 return $config;
 281                         } else {
 282                                 return false;
 283                         }
 284                 }
 285
 286                 // merge with primary and return
 287                 if (isset($config)) {
 288                         self::debug('. merging config files');
 289                         $config->append(self::build_from_array($config_lines));
 290                         return $config;
 291                 } else {
 292                         // return just secondary
 293                         $config = self::build_from_array($config_lines);
 294                         // if APC caching is available and enabled, mark this for cache
 295                         //$config->cache_in_apc = true;
 296                         $config->cache_key = $matched_name;
 297                         return $config;
 298                 }
 299         }
 300
 301         public static function build_from_array(array $lines) {
 302                 $config = new SiteConfig();
 303                 foreach ($lines as $line) {
 304                         $line = trim($line);
 305
 306                         // skip comments, empty lines
 307                         if ($line == '' || $line[0] == '#') continue;
 308
 309                         // get command
 310                         $command = explode(':', $line, 2);
 311                         // if there's no colon ':', skip this line
 312                         if (count($command) != 2) continue;
 313                         $val = trim($command[1]);
 314                         $command = trim($command[0]);
 315                         if ($command == '' || $val == '') continue;
 316
 317                         // check for commands where we accept multiple statements
 318                         if (in_array($command, array('title', 'body', 'author', 'date', 'strip', 'strip_id_or_class', 'strip_image_src', 'single_page_link', 'single_page_link_in_feed', 'next_page_link', 'http_header', 'test_url', 'find_string', 'replace_string'))) {
 319                                 array_push($config->$command, $val);
 320                         // check for single statement commands that evaluate to true or false
 321                         } elseif (in_array($command, array('tidy', 'prune', 'autodetect_on_failure'))) {
 322                                 $config->$command = ($val == 'yes');
 323                         // check for single statement commands stored as strings
 324                         } elseif (in_array($command, array('parser'))) {
 325                                 $config->$command = $val;
 326                         // check for replace_string(find): replace
 327                         } elseif ((substr($command, -1) == ')') && preg_match('!^([a-z0-9_]+)\((.*?)\)$!i', $command, $match)) {
 328                                 if (in_array($match[1], array('replace_string'))) {
 329                                         $command = $match[1];
 330                                         array_push($config->find_string, $match[2]);
 331                                         array_push($config->$command, $val);
 332                                 }
 333                         }
 334                 }
 335                 return $config;
 336         }
 337 }
 338 ?>