function _filter_url_escape_comments

Escapes the contents of HTML comments.

Callback for preg_replace_callback() within _filter_url().

Parameters

array $match: An array containing matches to replace from preg_replace_callback(), whereas $match[1] is expected to contain the content to be filtered.

bool|null $escape: (optional) A Boolean indicating whether to escape (TRUE) or unescape comments (FALSE). Defaults to NULL, indicating neither. If TRUE, statically cached $comments are reset.

Related topics

File

core/modules/filter/filter.module, line 651

Code

function _filter_url_escape_comments($match, $escape = NULL) {
    static $mode, $comments = [];
    if (isset($escape)) {
        $mode = $escape;
        if ($escape) {
            $comments = [];
        }
        return;
    }
    // Replace all HTML comments with a '<!-- [hash] -->' placeholder.
    if ($mode) {
        $content = $match[1];
        $hash = hash('sha256', $content);
        $comments[$hash] = $content;
        return "<!-- {$hash} -->";
    }
    else {
        $hash = $match[1];
        $hash = trim($hash);
        $content = $comments[$hash];
        return "<!--{$content}-->";
    }
}