ttrss/classes/feedparser.php

253 lines
6.2 KiB
PHP

<?php
class FeedParser {
/** @var DOMDocument */
private $doc;
/** @var string|null */
private $error = null;
/** @var array<string> */
private $libxml_errors = [];
/** @var array<FeedItem> */
private $items = [];
/** @var string|null */
private $link;
/** @var string|null */
private $title;
/** @var FeedParser::FEED_*|null */
private $type;
/** @var DOMXPath|null */
private $xpath;
const FEED_RDF = 0;
const FEED_RSS = 1;
const FEED_ATOM = 2;
function __construct(string $data) {
libxml_use_internal_errors(true);
libxml_clear_errors();
$this->doc = new DOMDocument();
$this->doc->loadXML($data);
mb_substitute_character("none");
$error = libxml_get_last_error();
if ($error) {
foreach (libxml_get_errors() as $error) {
if ($error->level == LIBXML_ERR_FATAL) {
// currently only the first error is reported
if (!isset($this->error)) {
$this->error = $this->format_error($error);
}
$this->libxml_errors[] = $this->format_error($error);
}
}
}
libxml_clear_errors();
}
function init() : void {
$root = $this->doc->firstChild;
$xpath = new DOMXPath($this->doc);
$xpath->registerNamespace('atom', 'http://www.w3.org/2005/Atom');
$xpath->registerNamespace('atom03', 'http://purl.org/atom/ns#');
$xpath->registerNamespace('media', 'http://search.yahoo.com/mrss/');
$xpath->registerNamespace('rdf', 'http://www.w3.org/1999/02/22-rdf-syntax-ns#');
$xpath->registerNamespace('slash', 'http://purl.org/rss/1.0/modules/slash/');
$xpath->registerNamespace('dc', 'http://purl.org/dc/elements/1.1/');
$xpath->registerNamespace('content', 'http://purl.org/rss/1.0/modules/content/');
$xpath->registerNamespace('thread', 'http://purl.org/syndication/thread/1.0');
$this->xpath = $xpath;
$root_list = $xpath->query("(//atom03:feed|//atom:feed|//channel|//rdf:rdf|//rdf:RDF)");
if (!empty($root_list) && $root_list->length > 0) {
/** @var DOMElement|null $root */
$root = $root_list->item(0);
if ($root) {
switch (mb_strtolower($root->tagName)) {
case "rdf:rdf":
$this->type = $this::FEED_RDF;
break;
case "channel":
$this->type = $this::FEED_RSS;
break;
case "feed":
case "atom:feed":
$this->type = $this::FEED_ATOM;
break;
default:
if (!isset($this->error)) {
$this->error = "Unknown/unsupported feed type";
}
return;
}
}
switch ($this->type) {
case $this::FEED_ATOM:
$title = $xpath->query("//atom:feed/atom:title")->item(0);
if (!$title)
$title = $xpath->query("//atom03:feed/atom03:title")->item(0);
if ($title) {
$this->title = $title->nodeValue;
}
$link = $xpath->query("//atom:feed/atom:link[not(@rel)]")->item(0);
if (!$link)
$link = $xpath->query("//atom:feed/atom:link[@rel='alternate']")->item(0);
if (!$link)
$link = $xpath->query("//atom03:feed/atom03:link[not(@rel)]")->item(0);
if (!$link)
$link = $xpath->query("//atom03:feed/atom03:link[@rel='alternate']")->item(0);
/** @var DOMElement|null $link */
if ($link && $link->hasAttributes()) {
$this->link = $link->getAttribute("href");
}
$articles = $xpath->query("//atom:entry");
if (empty($articles) || $articles->length == 0)
$articles = $xpath->query("//atom03:entry");
foreach ($articles as $article) {
array_push($this->items, new FeedItem_Atom($article, $this->doc, $this->xpath));
}
break;
case $this::FEED_RSS:
$title = $xpath->query("//channel/title")->item(0);
if ($title) {
$this->title = $title->nodeValue;
}
/** @var DOMElement|null $link */
$link = $xpath->query("//channel/link")->item(0);
if ($link) {
if ($link->getAttribute("href"))
$this->link = $link->getAttribute("href");
else if ($link->nodeValue)
$this->link = $link->nodeValue;
}
$articles = $xpath->query("//channel/item");
foreach ($articles as $article) {
array_push($this->items, new FeedItem_RSS($article, $this->doc, $this->xpath));
}
break;
case $this::FEED_RDF:
$xpath->registerNamespace('rssfake', 'http://purl.org/rss/1.0/');
$title = $xpath->query("//rssfake:channel/rssfake:title")->item(0);
if ($title) {
$this->title = $title->nodeValue;
}
$link = $xpath->query("//rssfake:channel/rssfake:link")->item(0);
if ($link) {
$this->link = $link->nodeValue;
}
$articles = $xpath->query("//rssfake:item");
foreach ($articles as $article) {
array_push($this->items, new FeedItem_RSS($article, $this->doc, $this->xpath));
}
break;
}
if ($this->title) $this->title = trim($this->title);
if ($this->link) $this->link = trim($this->link);
} else {
if (!isset($this->error)) {
$this->error = "Unknown/unsupported feed type";
}
return;
}
}
function format_error(LibXMLError $error) : string {
return sprintf("LibXML error %s at line %d (column %d): %s",
$error->code, $error->line, $error->column,
$error->message);
}
// libxml may have invalid unicode data in error messages
function error() : string {
return UConverter::transcode($this->error, 'UTF-8', 'UTF-8');
}
/** @return array<string> - WARNING: may return invalid unicode data */
function errors() : array {
return $this->libxml_errors;
}
function get_link() : string {
return clean($this->link ?? '');
}
function get_title() : string {
return clean($this->title ?? '');
}
/** @return array<FeedItem> */
function get_items() : array {
return $this->items;
}
/** @return array<string> */
function get_links(string $rel) : array {
$rv = array();
switch ($this->type) {
case $this::FEED_ATOM:
$links = $this->xpath->query("//atom:feed/atom:link");
foreach ($links as $link) {
if (!$rel || $link->hasAttribute('rel') && $link->getAttribute('rel') == $rel) {
array_push($rv, clean(trim($link->getAttribute('href'))));
}
}
break;
case $this::FEED_RSS:
$links = $this->xpath->query("//atom:link");
foreach ($links as $link) {
if (!$rel || $link->hasAttribute('rel') && $link->getAttribute('rel') == $rel) {
array_push($rv, clean(trim($link->getAttribute('href'))));
}
}
break;
}
return $rv;
}
}