root/branches/1.5/wp-includes/template-functions-links.php

<?php

function the_permalink() {
    echo apply_filters('the_permalink', get_permalink());
}

function permalink_link() { // For backwards compatibility
    echo apply_filters('the_permalink', get_permalink());
}

function permalink_anchor($mode = 'id') {
    global $id, $post;
    switch(strtolower($mode)) {
        case 'title':
            $title = sanitize_title($post->post_title) . '-' . $id;
            echo '<a id="'.$title.'"></a>';
            break;
        case 'id':
        default:
            echo '<a id="post-'.$id.'"></a>';
            break;
    }
}

function get_permalink($id = 0) {
    $rewritecode = array(
        '%year%',
        '%monthnum%',
        '%day%',
        '%hour%',
        '%minute%',
        '%second%',
        '%postname%',
        '%post_id%',
        '%category%',
        '%author%',
        '%pagename%'
    );

    $post = & get_post($id);
    if ($post->post_status == 'static') {
        return get_page_link($post->ID);
    }

    $permalink = get_settings('permalink_structure');

    if ('' != $permalink && 'draft' != $post->post_status) {
        $unixtime = strtotime($post->post_date);

        $category = '';
        if (strstr($permalink, '%category%')) {
            $cats = get_the_category($post->ID);
            $category = $cats[0]->category_nicename;
            if ($parent=$cats[0]->category_parent) $category = get_category_parents($parent, FALSE, '/', TRUE) . $category;
        }

        $authordata = get_userdata($post->post_author);
        $author = $authordata->user_nicename;
        $rewritereplace = 
        array(
            date('Y', $unixtime),
            date('m', $unixtime),
            date('d', $unixtime),
            date('H', $unixtime),
            date('i', $unixtime),
            date('s', $unixtime),
            $post->post_name,
            $post->ID,
            $category,
            $author,
            $post->post_name,
        );
        return apply_filters('post_link', get_settings('home') . str_replace($rewritecode, $rewritereplace, $permalink), $post);
    } else { // if they're not using the fancy permalink option
        $permalink = get_settings('home') . '/?p=' . $post->ID;
        return apply_filters('post_link', $permalink, $post);
    }
}

function get_page_link($id = false) {
    global $post, $wp_rewrite;

    if (! $id) {
        $id = $post->ID;
    }

    $pagestruct = $wp_rewrite->get_page_permastruct();

    if ('' != $pagestruct) {
        $link = get_page_uri($id);
        $link = str_replace('%pagename%', $link, $pagestruct);
        $link = get_settings('home') . "/$link/";
    } else {
        $link = get_settings('home') . "/?page_id=$id";
    }

    return apply_filters('page_link', $link, $id);
}

function get_year_link($year) {
    global $wp_rewrite;
    if (!$year) $year = gmdate('Y', time()+(get_settings('gmt_offset') * 3600));
        $yearlink = $wp_rewrite->get_year_permastruct();
    if (!empty($yearlink)) {
        $yearlink = str_replace('%year%', $year, $yearlink);
        return apply_filters('year_link', get_settings('home') . trailingslashit($yearlink), $year);
    } else {
        return apply_filters('year_link', get_settings('home') . '/?m=' . $year, $year);
    }
}

function get_month_link($year, $month) {
    global $wp_rewrite;
    if (!$year) $year = gmdate('Y', time()+(get_settings('gmt_offset') * 3600));
    if (!$month) $month = gmdate('m', time()+(get_settings('gmt_offset') * 3600));
        $monthlink = $wp_rewrite->get_month_permastruct();
    if (!empty($monthlink)) {
        $monthlink = str_replace('%year%', $year, $monthlink);
        $monthlink = str_replace('%monthnum%', zeroise(intval($month), 2), $monthlink);
        return apply_filters('month_link', get_settings('home') . trailingslashit($monthlink), $year, $month);
    } else {
        return apply_filters('month_link', get_settings('home') . '/?m=' . $year . zeroise($month, 2), $year, $month);
    }
}

function get_day_link($year, $month, $day) {
    global $wp_rewrite;
    if (!$year) $year = gmdate('Y', time()+(get_settings('gmt_offset') * 3600));
    if (!$month) $month = gmdate('m', time()+(get_settings('gmt_offset') * 3600));
    if (!$day) $day = gmdate('j', time()+(get_settings('gmt_offset') * 3600));

        $daylink = $wp_rewrite->get_day_permastruct();
    if (!empty($daylink)) {
        $daylink = str_replace('%year%', $year, $daylink);
        $daylink = str_replace('%monthnum%', zeroise(intval($month), 2), $daylink);
        $daylink = str_replace('%day%', zeroise(intval($day), 2), $daylink);
        return apply_filters('day_link', get_settings('home') . trailingslashit($daylink), $year, $month, $day);
    } else {
        return apply_filters('day_link', get_settings('home') . '/?m=' . $year . zeroise($month, 2) . zeroise($day, 2), $year, $month, $day);
    }
}

function get_feed_link($feed='rss2') {
    global $wp_rewrite;
    $do_perma = 0;
    $feed_url = get_settings('siteurl');
    $comment_feed_url = $feed_url;

    $permalink = $wp_rewrite->get_feed_permastruct();
    if ('' != $permalink) {
        if ( false !== strpos($feed, 'comments_') ) {
            $feed = str_replace('comments_', '', $feed);
            $permalink = $wp_rewrite->get_comment_feed_permastruct();
        }

        if ( 'rss2' == $feed )
            $feed = '';

        $permalink = str_replace('%feed%', $feed, $permalink);
        $permalink = preg_replace('#/+#', '/', "/$permalink/");
        $output =  get_settings('home') . $permalink;
    } else {
        if ( false !== strpos($feed, 'comments_') )
            $feed = str_replace('comments_', 'comments-', $feed);

        $output = get_settings('home') . "/?feed={$feed}";
    }

    return apply_filters('feed_link', $output, $feed);
}

function edit_post_link($link = 'Edit This', $before = '', $after = '') {
    global $user_ID, $post;

    get_currentuserinfo();

    if (!user_can_edit_post($user_ID, $post->ID)) {
        return;
    }

    $location = get_settings('siteurl') . "/wp-admin/post.php?action=edit&amp;post=$post->ID";
    echo "$before <a href=\"$location\">$link</a> $after";
}

function edit_comment_link($link = 'Edit This', $before = '', $after = '') {
    global $user_ID, $post, $comment;

    get_currentuserinfo();

    if (!user_can_edit_post_comments($user_ID, $post->ID)) {
        return;
    }

    $location = get_settings('siteurl') . "/wp-admin/post.php?action=editcomment&amp;comment=$comment->comment_ID";
    echo "$before <a href='$location'>$link</a> $after";
}

// Navigation links

function get_previous_post($in_same_cat = false, $excluded_categories = '') {
    global $post, $wpdb;

    if(! is_single()) {
        return null;
    }
    
    $current_post_date = $post->post_date;
    
    $join = '';
    if ($in_same_cat) {
        $join = " INNER JOIN $wpdb->post2cat ON $wpdb->posts.ID= $wpdb->post2cat.post_id ";
        $cat_array = get_the_category($post->ID);
         $join .= ' AND (category_id = ' . intval($cat_array[0]->cat_ID);
        for ($i = 1; $i < (count($cat_array)); $i++) {
            $join .= ' OR category_id = ' . intval($cat_array[$i]->cat_ID);
        }
        $join .= ')'; 
    }

    $sql_exclude_cats = '';
    if (!empty($excluded_categories)) {
        $blah = explode('and', $excluded_categories);
        foreach($blah as $category) {
            $category = intval($category);
            $sql_exclude_cats .= " AND post_category != $category";
        }
    }

    return @$wpdb->get_row("SELECT ID, post_title FROM $wpdb->posts $join WHERE post_date < '$current_post_date' AND post_status = 'publish' $sqlcat $sql_exclude_cats ORDER BY post_date DESC LIMIT 1");
}

function get_next_post($in_same_cat = false, $excluded_categories = '') {
    global $post, $wpdb;

    if(! is_single()) {
        return null;
    }

    $current_post_date = $post->post_date;
    
    $join = '';
    if ($in_same_cat) {
        $join = " INNER JOIN $wpdb->post2cat ON $wpdb->posts.ID= $wpdb->post2cat.post_id ";
        $cat_array = get_the_category($post->ID);
         $join .= ' AND (category_id = ' . intval($cat_array[0]->cat_ID);
        for ($i = 1; $i < (count($cat_array)); $i++) {
            $join .= ' OR category_id = ' . intval($cat_array[$i]->cat_ID);
        }
        $join .= ')'; 
    }

    $sql_exclude_cats = '';
    if (!empty($excluded_categories)) {
        $blah = explode('and', $excluded_categories);
        foreach($blah as $category) {
            $category = intval($category);
            $sql_exclude_cats .= " AND post_category != $category";
        }
    }

    $now = current_time('mysql');
    
    return @$wpdb->get_row("SELECT ID,post_title FROM $wpdb->posts $join WHERE post_date > '$current_post_date' AND post_date < '$now' AND post_status = 'publish' $sqlcat $sql_exclude_cats AND ID != $post->ID ORDER BY post_date ASC LIMIT 1");
}

function previous_post_link($format='&laquo; %link', $link='%title', $in_same_cat = false, $excluded_categories = '') {
  $post = get_previous_post($in_same_cat, $excluded_categories);

  if(! $post) {
    return;
  }

  $title = apply_filters('the_title', $post->post_title, $post);

  $string = '<a href="'.get_permalink($post->ID).'">';

  $link = str_replace('%title', $title, $link);

  $link = $string . $link . '</a>';

  $format = str_replace('%link', $link, $format);

  echo $format;        
}

function next_post_link($format='%link &raquo;', $link='%title', $in_same_cat = false, $excluded_categories = '') {
  $post = get_next_post($in_same_cat, $excluded_categories);

  if(! $post) {
    return;
  }

  $title = apply_filters('the_title', $post->post_title, $post);

  $string = '<a href="'.get_permalink($post->ID).'">';

  $link = str_replace('%title', $title, $link);

  $link = $string . $link . '</a>';

  $format = str_replace('%link', $link, $format);

  echo $format;        
}

// Deprecated.  Use previous_post_link().
function previous_post($format='%', $previous='previous post: ', $title='yes', $in_same_cat='no', $limitprev=1, $excluded_categories='') {

    if ( empty($in_same_cat) || 'no' == $in_same_cat )
        $in_same_cat = false;
    else
        $in_same_cat = true;

  $post = get_previous_post($in_same_cat, $excluded_categories);

  if(! $post) {
    return;
  }

    $string = '<a href="'.get_permalink($post->ID).'">'.$previous;
    if ($title == 'yes') {
        $string .= apply_filters('the_title', $post->post_title, $post);
    }
    $string .= '</a>';
    $format = str_replace('%', $string, $format);
    echo $format;
}

// Deprecated.  Use next_post_link().
function next_post($format='%', $next='next post: ', $title='yes', $in_same_cat='no', $limitnext=1, $excluded_categories='') {
    
    if ( empty($in_same_cat) || 'no' == $in_same_cat )
        $in_same_cat = false;
    else
        $in_same_cat = true;

  $post = get_next_post($in_same_cat, $excluded_categories);

  if(! $post) {
    return;
  }

    $string = '<a href="'.get_permalink($post->ID).'">'.$next;
    if ($title=='yes') {
        $string .= apply_filters('the_title', $post->post_title, $nextpost);
    }
    $string .= '</a>';
    $format = str_replace('%', $string, $format);
    echo $format;
}

function get_pagenum_link($pagenum = 1) {
    global $wp_rewrite;

    $qstr = wp_specialchars($_SERVER['REQUEST_URI']);

    $page_querystring = "paged"; 
    $page_modstring = "page/";
    $page_modregex = "page/?";
    $permalink = 0;

    $home_root = parse_url(get_settings('home'));
    $home_root = $home_root['path'];
    $home_root = trailingslashit($home_root);
    $qstr = preg_replace('|^'. $home_root . '|', '', $qstr);
    $qstr = preg_replace('|^/+|', '', $qstr);

    $index = $_SERVER['PHP_SELF'];
    $index = preg_replace('|^'. $home_root . '|', '', $index);
    $index = preg_replace('|^/+|', '', $index);

    // if we already have a QUERY style page string
    if( stristr( $qstr, $page_querystring ) ) {
        $replacement = "$page_querystring=$pagenum";
        $qstr = preg_replace("/".$page_querystring."[^\d]+\d+/", $replacement, $qstr);
        // if we already have a mod_rewrite style page string
    } elseif ( preg_match( '|'.$page_modregex.'\d+|', $qstr ) ){
        $permalink = 1;
        $qstr = preg_replace('|'.$page_modregex.'\d+|',"$page_modstring$pagenum",$qstr);

        // if we don't have a page string at all ...
        // lets see what sort of URL we have...
    } else {
        // we need to know the way queries are being written
        // if there's a querystring_start (a "?" usually), it's definitely not mod_rewritten
        if ( stristr( $qstr, '?' ) ){
            // so append the query string (using &, since we already have ?)
            $qstr .=  '&amp;' . $page_querystring . '=' . $pagenum;
            // otherwise, it could be rewritten, OR just the default index ...
        } elseif( '' != get_settings('permalink_structure') && ! is_admin()) {
            $permalink = 1;
            $index = $wp_rewrite->index;
            // If it's not a path info permalink structure, trim the index.
            if (! $wp_rewrite->using_index_permalinks()) {
                $qstr = preg_replace("#/*" . $index . "/*#", '/', $qstr);
            } else {
                // If using path info style permalinks, make sure the index is in
                // the URI.
                if (strpos($qstr, $index) === false) {
                    $qstr = '/' . $index . $qstr;
                }
            }

            $qstr =  trailingslashit($qstr) . $page_modstring . $pagenum;
        } else {
            $qstr = $index . '?' . $page_querystring . '=' . $pagenum;
        }
    }

    $qstr = preg_replace('|^/+|', '', $qstr);
    if ($permalink) $qstr = trailingslashit($qstr);
    return preg_replace('/&([^#])(?![a-z]{1,8};)/', '&#038;$1', trailingslashit( get_settings('home') ) . $qstr );
}

function next_posts($max_page = 0) { // original by cfactor at cooltux.org
    global $paged, $pagenow;

     if (! is_single()) {
         if (!$paged) $paged = 1;
         $nextpage = intval($paged) + 1;
         if (!$max_page || $max_page >= $nextpage) {
             echo get_pagenum_link($nextpage);
         }         
     }
}

function next_posts_link($label='Next Page &raquo;', $max_page=0) {
    global $paged, $result, $request, $posts_per_page, $wpdb, $max_num_pages;
    if (!$max_page) {
            if ( isset($max_num_pages) ) {
                $max_page = $max_num_pages;
            } else {
        preg_match('#FROM (.*) GROUP BY#', $request, $matches);
        $fromwhere = $matches[1];
        $numposts = $wpdb->get_var("SELECT COUNT(ID) FROM $fromwhere");
        $max_page = $max_num_pages = ceil($numposts / $posts_per_page);
            }
    }
    if (!$paged)
        $paged = 1;
    $nextpage = intval($paged) + 1;
    if ((! is_single()) && (empty($paged) || $nextpage <= $max_page)) {
        echo '<a href="';