parse_netscape_bookmarks.php

<?php

/**
 * Basically netscape bookmark files often come so badly formed, there's
 * no reliable way I could find to parse them with DOM or SimpleXML,
 * even after running HTML Tidy on them. So, this function does a bunch of
 * transformations on the general format of a netscape bookmark file, to get
 * Each bookmark and its description onto one line, and goes through line by
 * line, matching tags and attributes. It's messy, but it works better than
 * anything I could find in hours of googling, and anything that I could
 * write after hours with DOM and SimpleXML. I didn't want to pull in a big
 * DOM parsing library just to do this one thing, so this is it.
 * @todo - running Tidy before doing this might be beneficial.
 *   ?? $bkmk_str = tidy_parse_string($bkmk_str)->cleanRepair();
 *
 * Update 2013-07-08:
 *     Just tested this on an export of some bookmarks from Pinboard.in
 *     and it seems that it is still working, so good for me.
 */

/*
print '<PRE>';
var_dump(parse_netscape_bookmarks(file_get_contents('bookmarks_export.htm')));
*/

function parse_netscape_bookmarks($bkmk_str, $default_tag = null) {
    $i = 0;
    $next = false;
    $items = [];

    $current_tag = $default_tag = $default_tag ?: 'imported-'.date("Ymd");

    $bkmk_str = str_replace(["\r","\n","\t"], ['','',' '], $bkmk_str);

    $bkmk_str = preg_replace_callback('@<dd>(.*?)(<A|<\/|<DL|<DT|<P)@mis', function($m) {
        return '<dd>'.str_replace(["\r", "\n"], ['', '<br>'], trim($m[1])).'</';
    }, $bkmk_str);

    $bkmk_str = preg_replace('/>(\s*?)</mis', ">\n<", $bkmk_str);
    $bkmk_str = preg_replace('/(<!DOCTYPE|<META|<!--|<TITLE|<H1|<P)(.*?)\n/i', '', $bkmk_str);

    $bkmk_str = trim($bkmk_str);
    $bkmk_str = preg_replace('/\n<dd/i', '<dd', $bkmk_str);

    $lines = explode("\n", $bkmk_str);

    $str_bool = function($str, $default = false) {
        if (!$str) {
            return false;
        } elseif (!is_string($str) && $str) {
            return true;
        }

        $true  = 'y|yes|on|checked|ok|1|true|array|\+|okay|yes+|t|one';
        $false = 'n|no|off|empty|null|false|0|-|exit|die|neg|f|zero|void';

        if (preg_match("/^($true)$/i", $str)) {
            return true;
        } elseif (preg_match("/^($false)$/i", $str)) {
            return false;
        }

        return $default;
    };

    foreach ($lines as $line_no => $line) {
        /* If we match a tag, set current tag to that, if <DL>, stop tag. */
        if (preg_match('/^<h\d(.*?)>(.*?)<\/h\d>/i', $line, $m1)) {
            $current_tag = $m1[2];

            continue;
        } elseif (preg_match('/^<\/DL>/i', $line)) {
            $current_tag = $default_tag;
        }

        if (preg_match('/<a/i', $line, $m2)) {
            if ($current_tag) {
                $items[$i]['tags'] = $current_tag;
            }

            if (preg_match('/href="(.*?)"/i', $line, $m3)) {
                $items[$i]['uri'] = $m3[1];
                // $items[$i]['meta'] = meta($m3[1]);
            } else {
                $items[$i]['uri'] = '';
                // $items[$i]['meta'] = '';
            }

            if (preg_match('/<a(.*?)>(.*?)<\/a>/i', $line, $m4)) {
                $items[$i]['title'] = $m4[2];
                // $items[$i]['slug'] = slugify($m4[2]);
            } else {
                $items[$i]['title'] = 'untitled';
                // $items[$i]['slug'] = '';
            }

            if (preg_match('/note="(.*?)"<\/a>/i', $line, $m5)) {
                 $items[$i]['note'] = $m5[1];
            } elseif (preg_match('/<dd>(.*?)<\//i', $line, $m6)) {
                 $items[$i]['note'] = str_replace('<br>', "\n", $m6[1]);
            } else {
                $items[$i]['note'] = '';
            }

            if (preg_match('/(tags?|labels?|folders?)="(.*?)"/i', $line, $m7)) {
                 $items[$i]['tags'] = strtr($m7[2], ',', ' ');
            } else {
                $items[$i]['tags'] = $current_tag;
            }

            if (preg_match('/add_date="(.*?)"/i', $line, $m8)) {
                 $items[$i]['time'] = strtotime($m8[0]) ?: time();
            } else {
                $items[$i]['time'] = time();
            }

            if (preg_match('/(public|published|pub)="(.*?)"/i', $line, $m9)) {
                $items[$i]['pub'] = $str_bool($m9[2], false) ? 1 : 0;
            } elseif (preg_match('/(private|shared)="(.*?)"/i', $line, $m10)) {
                $items[$i]['pub'] = $str_bool($m10[2], true) ? 0 : 1;
            }

            $i++;
        }
    }
    ksort($items);

    return $items;
}