diff options
| -rw-r--r-- | bridges/WordPressBridge.php | 19 | ||||
| -rw-r--r-- | bridges/ZDNetBridge.php | 2 | ||||
| -rw-r--r-- | lib/html.php | 85 |
3 files changed, 91 insertions, 15 deletions
diff --git a/bridges/WordPressBridge.php b/bridges/WordPressBridge.php index 7f419f1d..1d46958d 100644 --- a/bridges/WordPressBridge.php +++ b/bridges/WordPressBridge.php @@ -74,20 +74,8 @@ class WordPressBridge extends FeedExpander } } - // Convert lazy-loading images and iframes (videos...) - foreach ($article->find('img, iframe') as $img) { - if (!empty($img->getAttribute('data-src'))) { - $img->src = $img->getAttribute('data-src'); - } elseif (!empty($img->getAttribute('data-srcset'))) { - $img->src = explode(' ', $img->getAttribute('data-srcset'))[0]; - } elseif (!empty($img->getAttribute('data-lazy-src'))) { - $img->src = $img->getAttribute('data-lazy-src'); - } elseif (!empty($img->getAttribute('srcset'))) { - $img->src = explode(' ', $img->getAttribute('srcset'))[0]; - } - } - // Find article main image + $article = convertLazyLoading($article); $article_image = $article_html->find('img.wp-post-image', 0); if (!empty($item['content']) && (!is_object($article_image) || empty($article_image->src))) { $article_image = str_get_html($item['content'])->find('img.wp-post-image', 0); @@ -105,6 +93,11 @@ class WordPressBridge extends FeedExpander } } + // Unwrap images figures + foreach ($article->find('figure.wp-block-image') as $figure) { + $figure->outertext = $figure->innertext; + } + if (!is_null($article)) { $item['content'] = $this->cleanContent($article->innertext); $item['content'] = defaultLinkTo($item['content'], $item['uri']); diff --git a/bridges/ZDNetBridge.php b/bridges/ZDNetBridge.php index 0bebeff8..693f542c 100644 --- a/bridges/ZDNetBridge.php +++ b/bridges/ZDNetBridge.php @@ -208,7 +208,7 @@ class ZDNetBridge extends FeedExpander $contents = stripWithDelimiters($contents, '<meta itemprop="image"', '>'); $contents = stripWithDelimiters($contents, '<svg class="svg-symbol', '</svg>'); $contents = trim(stripWithDelimiters($contents, '<section class="sharethrough-top', '</section>')); - $item['content'] = $contents; + $item['content'] = convertLazyLoading($contents); return $item; } diff --git a/lib/html.php b/lib/html.php index 873620bd..8ec30069 100644 --- a/lib/html.php +++ b/lib/html.php @@ -201,6 +201,69 @@ function defaultLinkTo($dom, $url) } /** + * Convert lazy-loading images and frames (video embeds) into static elements + * + * This function looks for lazy-loading attributes such as 'data-src' and converts + * them back to regular ones such as 'src', making them loadable in RSS readers. + * It also converts <picture> elements to plain <img> elements. + * + * @param string|object $content The HTML content. Supports HTML objects or string objects + * @return string|object Content with fixed image/frame URLs (same type as input). + */ +function convertLazyLoading($dom) +{ + $string_convert = false; + if (is_string($dom)) { + $string_convert = true; + $dom = str_get_html($dom); + } + + // Process standalone images, embeds and picture sources + foreach ($dom->find('img, iframe, source') as $img) { + if (!empty($img->getAttribute('data-src'))) { + $img->src = $img->getAttribute('data-src'); + } elseif (!empty($img->getAttribute('data-srcset'))) { + $img->src = explode(' ', $img->getAttribute('data-srcset'))[0]; + } elseif (!empty($img->getAttribute('data-lazy-src'))) { + $img->src = $img->getAttribute('data-lazy-src'); + } elseif (!empty($img->getAttribute('srcset'))) { + $img->src = explode(' ', $img->getAttribute('srcset'))[0]; + } else { + continue; // Proceed to next element without removing attributes + } + foreach (['loading', 'decoding', 'srcset', 'data-src', 'data-srcset'] as $attr) { + if ($img->hasAttribute($attr)) { + $img->removeAttribute($attr); + } + } + } + + // Convert complex HTML5 pictures to plain, standalone images + // <img> and <source> tags already have their "src" attribute set at this point, + // so we replace the whole <picture> with a standalone <img> from within the <picture> + foreach ($dom->find('picture') as $picture) { + $img = $picture->find('img, source', 0); + if (!empty($img)) { + if ($img->tag == 'source') { + $img->tag = 'img'; + } + // Adding/removing node would change its position inside the parent element, + // So instead we rewrite the node in-place though the outertext attribute + $picture->outertext = $img->outertext; + } + } + + // If the expected return type is object, reload the DOM to make sure + // all $picture->outertext rewritten above are converted back to objects + $dom = $dom->outertext; + if (!$string_convert) { + $dom = str_get_html($dom); + } + + return $dom; +} + +/** * Extract the first part of a string matching the specified start and end delimiters * * @param string $string Input string, e.g. `<div>Post author: John Doe</div>` @@ -245,27 +308,47 @@ function stripWithDelimiters($string, $start, $end) * @param string $tag_start Start of the HTML tag to remove, e.g. `<div class="ads">` * @return string Cleaned String, e.g. `foobar` * - * @todo This function needs more documentation to make it maintainable. + * This function works by locating the desired tag start, then finding the appropriate + * end by counting opening and ending tags until the amount of open tags reaches zero: + * + * ``` + * Amount of open tags: + * 1 2 1 0 + * |---------------||---| |----| |----| + * <div class="ads"><div>ads</div>ads</div>bar + * | <-------- Section to remove -------> | + * ``` */ function stripRecursiveHTMLSection($string, $tag_name, $tag_start) { $open_tag = '<' . $tag_name; $close_tag = '</' . $tag_name . '>'; $close_tag_length = strlen($close_tag); + + // Make sure the provided $tag_start argument matches the provided $tag_name argument if (strpos($tag_start, $open_tag) === 0) { + // While tag_start is present, there is at least one remaining section to remove while (strpos($string, $tag_start) !== false) { + // In order to locate the end of the section, we attempt each closing tag until we find the right one + // We know we found the right one when the amount of "<tag" is the same as amount of "</tag" + // When the attempted "</tag" is not the correct one, we increase $search_offset to skip it + // and retry unless $max_recursion is reached (prevents infinite loop on malformed HTML) $max_recursion = 100; $section_to_remove = null; $section_start = strpos($string, $tag_start); $search_offset = $section_start; do { $max_recursion--; + // Move on to the next occurrence of "</tag" $section_end = strpos($string, $close_tag, $search_offset); $search_offset = $section_end + $close_tag_length; + // If the next "</tag" is the correct one, then this is the section we must remove: $section_to_remove = substr($string, $section_start, $section_end - $section_start + $close_tag_length); + // Count amount of "<tag" and "</tag" in the section to remove $open_tag_count = substr_count($section_to_remove, $open_tag); $close_tag_count = substr_count($section_to_remove, $close_tag); } while ($open_tag_count > $close_tag_count && $max_recursion > 0); + // We exited the loop, let's remove the section $string = str_replace($section_to_remove, '', $string); } } |