full-text-rss/libraries/content-extractor/SiteConfig.php
2019-04-04 23:46:36 +02:00

463 lines
18 KiB
PHP

<?php
/**
* Site Config
*
* Each instance of this class should hold extraction patterns and other directives
* for a website. See ContentExtractor class to see how it's used.
*
* @version 1.1
* @date 2017-09-25
* @author Keyvan Minoukadeh
* @copyright 2017 Keyvan Minoukadeh
* @license http://www.gnu.org/licenses/agpl-3.0.html AGPL v3
*/
class SiteConfig
{
// Use first matching element as title (0 or more xpath expressions)
public $title = array();
// Use first matching element as body (0 or more xpath expressions)
public $body = array();
// Use first matching element as author (0 or more xpath expressions)
public $author = array();
// Use first matching element as date (0 or more xpath expressions)
public $date = array();
// Strip elements matching these xpath expressions (0 or more)
public $strip = array();
// Strip elements which contain these strings (0 or more) in the id or class attribute
public $strip_id_or_class = array();
// Strip images which contain these strings (0 or more) in the src attribute
public $strip_image_src = array();
// Mark article as a native ad if any of these expressions match (0 or more xpath expressions)
public $native_ad_clue = array();
// Additional HTTP headers to send (associative array)
public $http_header = array();
// Process HTML with tidy before creating DOM (bool or null if undeclared)
public $tidy = null;
protected $default_tidy = true; // used if undeclared
// Autodetect title/body if xpath expressions fail to produce results.
// Note that this applies to title and body separately, ie.
// * if we get a body match but no title match, this option will determine whether we autodetect title
// * if neither match, this determines whether we autodetect title and body.
// Also note that this only applies when there is at least one xpath expression in title or body, ie.
// * if title and body are both empty (no xpath expressions), this option has no effect (both title and body will be auto-detected)
// * 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.
// 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).
// bool or null if undeclared
public $autodetect_on_failure = null;
protected $default_autodetect_on_failure = true; // used if undeclared
// Clean up content block - attempt to remove elements that appear to be superfluous
// bool or null if undeclared
public $prune = null;
protected $default_prune = true; // used if undeclared
// Test URL - if present, can be used to test the config above
public $test_url = array();
// Test URL contains - one or more snippets of text from the article body.
// Used to determine if the extraction rules for the site are still valid (ie. still extracting relevant content)
// Keys should be one or more of the test URLs supplied, and value an array of strings to look for.
public $test_contains = array();
// If page contains - XPath expression. Used to determine if the preceding rule gets evaluated or not.
// Currently only works with single_page_link.
public $if_page_contains = array();
// Single-page link - should identify a link element or URL pointing to the page holding the entire article
// This is useful for sites which split their articles across multiple pages. Links to such pages tend to
// display the first page with links to the other pages at the bottom. Often there is also a link to a page
// which displays the entire article on one page (e.g. 'print view').
// This should be an XPath expression identifying the link to that page. If present and we find a match,
// we will retrieve that page and the rest of the options in this config will be applied to the new page.
public $single_page_link = array();
public $next_page_link = array();
// Single-page link in feed? - same as above, but patterns applied to item description HTML taken from feed
public $single_page_link_in_feed = array();
// Which parser to use for turning raw HTML into a DOMDocument (either 'libxml' or 'html5lib')
// string or null if undeclared
public $parser = null;
protected $default_parser = 'libxml'; // used if undeclared
// Insert detected image (currently only og:image) into beginning of extracted article
// Only does this if extracted article contains no images
// bool or null if undeclared
public $insert_detected_image = null;
protected $default_insert_detected_image = true; // used if undeclared
// Strings to search for in HTML before processing begins (used with $replace_string)
public $find_string = array();
// Strings to replace those found in $find_string before HTML processing begins
public $replace_string = array();
// the options below cannot be set in the config files which this class represents
//public $cache_in_apc = false; // used to decide if we should cache in apc or not
public static $debug = false;
protected static $apc = false;
protected static $config_path_custom;
protected static $config_path_fallback;
protected static $config_cache = array();
const HOSTNAME_REGEX = '/^(([a-zA-Z0-9-]*[a-zA-Z0-9])\.)*([A-Za-z0-9-]*[A-Za-z0-9])$/';
protected static function debug($msg) {
if (self::$debug) {
//$mem = round(memory_get_usage()/1024, 2);
//$memPeak = round(memory_get_peak_usage()/1024, 2);
echo '* ',$msg;
//echo ' - mem used: ',$mem," (peak: $memPeak)\n";
echo "\n";
ob_flush();
flush();
}
}
// enable APC caching of certain site config files?
// If enabled the following site config files will be
// cached in APC cache (when requested for first time):
// * anything in site_config/custom/ and its corresponding file in site_config/standard/
// * the site config files associated with HTML fingerprints
// * the global site config file
// returns true if enabled, false otherwise
public static function use_apc($apc=true) {
if (!function_exists('apc_add')) {
if ($apc) self::debug('APC will not be used (function apc_add does not exist)');
return false;
}
self::$apc = $apc;
return $apc;
}
// return bool or null
public function insert_detected_image($use_default=true) {
if ($use_default) return (isset($this->insert_detected_image)) ? $this->insert_detected_image : $this->default_insert_detected_image;
return $this->insert_detected_image;
}
// return bool or null
public function tidy($use_default=true) {
if ($use_default) return (isset($this->tidy)) ? $this->tidy : $this->default_tidy;
return $this->tidy;
}
// return bool or null
public function prune($use_default=true) {
if ($use_default) return (isset($this->prune)) ? $this->prune : $this->default_prune;
return $this->prune;
}
// return string or null
public function parser($use_default=true) {
if ($use_default) return (isset($this->parser)) ? $this->parser : $this->default_parser;
return $this->parser;
}
// return bool or null
public function autodetect_on_failure($use_default=true) {
if ($use_default) return (isset($this->autodetect_on_failure)) ? $this->autodetect_on_failure : $this->default_autodetect_on_failure;
return $this->autodetect_on_failure;
}
public static function set_config_path($path, $fallback=null) {
self::$config_path_custom = $path;
self::$config_path_fallback = $fallback;
}
protected static function load_cached_merged($host, $exact_host_match) {
if ($exact_host_match) {
$key = $host.'.merged.ex';
} else {
$key = $host.'.merged';
}
return self::load_cached($key);
}
protected static function add_to_cache_merged($host, $exact_host_match, SiteConfig $config=null) {
if ($exact_host_match) {
$key = $host.'.merged.ex';
} else {
$key = $host.'.merged';
}
if (!isset($config)) $config = new SiteConfig();
self::add_to_cache($key, $config);
}
public static function add_to_cache($key, SiteConfig $config, $use_apc=true) {
$key = strtolower($key);
if (substr($key, 0, 4) == 'www.') $key = substr($key, 4);
self::$config_cache[$key] = $config;
if (self::$apc && $use_apc) {
self::debug("Adding site config to APC cache with key sc.$key");
apc_add("sc.$key", $config);
}
self::debug("Cached site config with key $key");
}
public static function load_cached($key) {
$key = strtolower($key);
if (substr($key, 0, 4) == 'www.') $key = substr($key, 4);
//var_dump('in cache?', $key, self::$config_cache);
if (array_key_exists($key, self::$config_cache)) {
self::debug("... site config for $key already loaded in this request");
return self::$config_cache[$key];
} elseif (self::$apc && ($sconfig = apc_fetch("sc.$key"))) {
self::debug("... site config for $key found in APCu");
return $sconfig;
}
return false;
}
public static function is_cached($key) {
$key = strtolower($key);
if (substr($key, 0, 4) == 'www.') $key = substr($key, 4);
if (array_key_exists($key, self::$config_cache)) {
return true;
} elseif (self::$apc && (bool)apc_fetch("sc.$key")) {
return true;
}
return false;
}
public function append(SiteConfig $newconfig) {
// check for commands where we accept multiple statements (no test_url)
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', 'native_ad_clue') as $var) {
// append array elements for this config variable from $newconfig to this config
//$this->$var = $this->$var + $newconfig->$var;
$this->$var = array_unique(array_merge($this->$var, $newconfig->$var));
}
// special handling of commands where key is important and config values being appended should not overwrite existing ones
foreach (array('http_header') as $var) {
$this->$var = array_merge($newconfig->$var, $this->$var);
}
// special handling of if_page_contains directive
foreach (array('single_page_link') as $var) {
if (isset($this->if_page_contains[$var]) && isset($newconfig->if_page_contains[$var])) {
$this->if_page_contains[$var] = array_merge($newconfig->if_page_contains[$var], $this->if_page_contains[$var]);
} elseif (isset($newconfig->if_page_contains[$var])) {
$this->if_page_contains[$var] = $newconfig->if_page_contains[$var];
}
}
// check for single statement commands
// we do not overwrite existing non null values
foreach (array('tidy', 'prune', 'parser', 'autodetect_on_failure', 'insert_detected_image') as $var) {
if ($this->$var === null) $this->$var = $newconfig->$var;
}
// treat find_string and replace_string separately (don't apply array_unique) (thanks fabrizio!)
foreach (array('find_string', 'replace_string') as $var) {
// append array elements for this config variable from $newconfig to this config
//$this->$var = $this->$var + $newconfig->$var;
$this->$var = array_merge($this->$var, $newconfig->$var);
}
}
// Add test_contains to last test_url
public function add_test_contains($test_contains) {
if (!empty($this->test_url)) {
$test_contains = (string) $test_contains;
$key = end($this->test_url);
reset($this->test_url);
if (isset($this->test_contains[$key])) {
$this->test_contains[$key][] = $test_contains;
} else {
$this->test_contains[$key] = array($test_contains);
}
}
}
// Add if_page_page_contains
// TODO: Expand so it can be used with other rules too
public function add_if_page_contains_condition($if_page_contains) {
if (!empty($this->single_page_link)) {
$if_page_contains = (string) $if_page_contains;
$key = end($this->single_page_link);
reset($this->single_page_link);
$this->if_page_contains['single_page_link'][$key] = $if_page_contains;
}
}
public function get_if_page_contains_condition($directive_name, $directive_value) {
if (isset($this->if_page_contains[$directive_name])) {
if (isset($this->if_page_contains[$directive_name][$directive_value])) {
return $this->if_page_contains[$directive_name][$directive_value];
}
}
return null;
}
// returns SiteConfig instance if an appropriate one is found, false otherwise
// if $exact_host_match is true, we will not look for wildcard config matches
// by default if host is 'test.example.org' we will look for and load '.example.org.txt' if it exists
public static function build($host, $exact_host_match=false) {
$host = strtolower($host);
if (substr($host, 0, 4) == 'www.') $host = substr($host, 4);
if (!$host || (strlen($host) > 200) || !preg_match(self::HOSTNAME_REGEX, ltrim($host, '.'))) return false;
// got a merged one?
$config = self::load_cached_merged($host, $exact_host_match);
if ($config) {
//self::debug('. returned merged config from a previous request');
return $config;
}
// check for site configuration
$try = array($host);
// should we look for wildcard matches
if (!$exact_host_match) {
$split = explode('.', $host);
if (count($split) > 1) {
array_shift($split);
$try[] = '.'.implode('.', $split);
}
}
// look for site config file in custom folder
self::debug(". looking for site config for $host in custom folder");
//var_dump($try);
$config = null;
$config_std = null;
foreach ($try as $h) {
//$h_key = $h.'.'.$key_suffix;
$h_key = $h.'.custom';
//var_dump($h_key, $h);
if ($config = self::load_cached($h_key)) {
break;
} elseif (file_exists(self::$config_path_custom."/$h.txt")) {
self::debug("... found site config ($h.txt)");
$file_custom = self::$config_path_custom."/$h.txt";
$config = self::build_from_file($file_custom);
//$matched_name = $h;
break;
}
}
// if we found site config, process it
// if autodetec on failure is off (on by default) we do not need to look
// in secondary folder
if ($config && !$config->autodetect_on_failure()) {
self::debug('... autodetect on failure is disabled (no other site config files will be loaded)');
self::add_to_cache_merged($host, $exact_host_match, $config);
return $config;
}
// look for site config file in secondary folder
if (isset(self::$config_path_fallback)) {
self::debug(". looking for site config for $host in standard folder");
foreach ($try as $h) {
if ($config_std = self::load_cached($h)) {
break;
} elseif (file_exists(self::$config_path_fallback."/$h.txt")) {
self::debug("... found site config in standard folder ($h.txt)");
$file_secondary = self::$config_path_fallback."/$h.txt";
$config_std = self::build_from_file($file_secondary);
break;
}
}
}
// return false if no config file found
if (!$config && !$config_std) {
self::debug("... no site config match for $host");
self::add_to_cache_merged($host, $exact_host_match);
return false;
}
// final config handling
$config_final = null;
if (!$config_std && $config) {
$config_final = $config;
// merge with primary
} elseif ($config_std && $config) {
self::debug('. merging config files');
$config->append($config_std);
$config_final = $config;
} else {
// return just secondary
//$config = self::build_from_array($config_lines);
// if APC caching is available and enabled, mark this for cache
//$config->cache_in_apc = true;
$config_final = $config_std;
}
self::add_to_cache_merged($host, $exact_host_match, $config_final);
return $config_final;
}
public static function build_from_file($path, $cache=true) {
$key = basename($path, '.txt');
$config_lines = file($path, FILE_IGNORE_NEW_LINES | FILE_SKIP_EMPTY_LINES);
if (!$config_lines || !is_array($config_lines)) return false;
$config = self::build_from_array($config_lines);
if ($cache) self::add_to_cache($key, $config);
return $config;
}
public static function build_from_string($string) {
$config_lines = explode("\n", $string);
return self::build_from_array($config_lines);
}
public static function build_from_array(array $lines) {
$config = new SiteConfig();
foreach ($lines as $line) {
$line = trim($line);
// skip comments, empty lines
if ($line == '' || $line[0] == '#') continue;
// get command
$command = explode(':', $line, 2);
// if there's no colon ':', skip this line
if (count($command) != 2) continue;
$val = trim($command[1]);
$command = trim($command[0]);
//if ($command == '' || $val == '') continue;
// $val can be empty, e.g. replace_string:
if ($command == '') continue;
// strip_attr is now an alias for strip.
// In FTR 3.8 we can strip attributes from elements, not only the elements themselves
// e.g. strip: //img/@srcset (removes srcset attribute from all img elements)
// but for backward compatibility (to avoid errors with new config files + old version of FTR)
// we've introduced strip_attr and we'll recommend using that in our public site config rep.
// strip_attr: //img/@srcset
if ($command == 'strip_attr') $command = 'strip';
// check for commands where we accept multiple statements
if (in_array($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', 'native_ad_clue', 'http_header', 'test_url', 'find_string', 'replace_string'))) {
array_push($config->$command, $val);
// check for single statement commands that evaluate to true or false
} elseif (in_array($command, array('tidy', 'prune', 'autodetect_on_failure', 'insert_detected_image'))) {
$config->$command = ($val == 'yes');
// check for single statement commands stored as strings
} elseif (in_array($command, array('parser'))) {
$config->$command = $val;
// special treatment for test_contains
} elseif (in_array($command, array('test_contains'))) {
$config->add_test_contains($val);
// special treatment for if_page_contains
} elseif (in_array($command, array('if_page_contains'))) {
$config->add_if_page_contains_condition($val);
// check for replace_string(find): replace
} elseif ((substr($command, -1) == ')') && preg_match('!^([a-z0-9_]+)\((.*?)\)$!i', $command, $match)) {
if (in_array($match[1], array('replace_string'))) {
array_push($config->find_string, $match[2]);
array_push($config->replace_string, $val);
} elseif (in_array($match[1], array('http_header'))) {
$_header = strtolower(trim($match[2]));
$config->http_header[$_header] = $val;
}
}
}
return $config;
}
}