source: trunk/wp-includes/post-template.php @ 15264

<?php
/**
 * WordPress Post Template Functions.
 *
 * Gets content for the current post in the loop.
 *
 * @package WordPress
 * @subpackage Template
 */

/**
 * Display the ID of the current item in the WordPress Loop.
 *
 * @since 0.71
 * @uses $id
 */
function the_ID() {
        global $id;
        echo $id;
}

/**
 * Retrieve the ID of the current item in the WordPress Loop.
 *
 * @since 2.1.0
 * @uses $id
 *
 * @return unknown
 */
function get_the_ID() {
        global $id;
        return $id;
}

/**
 * Display or retrieve the current post title with optional content.
 *
 * @since 0.71
 *
 * @param string $before Optional. Content to prepend to the title.
 * @param string $after Optional. Content to append to the title.
 * @param bool $echo Optional, default to true.Whether to display or return.
 * @return null|string Null on no title. String if $echo parameter is false.
 */
function the_title($before = '', $after = '', $echo = true) {
        $title = get_the_title();

        if ( strlen($title) == 0 )
                return;

        $title = $before . $title . $after;

        if ( $echo )
                echo $title;
        else
                return $title;
}

/**
 * Sanitize the current title when retrieving or displaying.
 *
 * Works like {@link the_title()}, except the parameters can be in a string or
 * an array. See the function for what can be override in the $args parameter.
 *
 * The title before it is displayed will have the tags stripped and {@link
 * esc_attr()} before it is passed to the user or displayed. The default
 * as with {@link the_title()}, is to display the title.
 *
 * @since 2.3.0
 *
 * @param string|array $args Optional. Override the defaults.
 * @return string|null Null on failure or display. String when echo is false.
 */
function the_title_attribute( $args = '' ) {
        $title = get_the_title();

        if ( strlen($title) == 0 )
                return;

        $defaults = array('before' => '', 'after' =>  '', 'echo' => true);
        $r = wp_parse_args($args, $defaults);
        extract( $r, EXTR_SKIP );


        $title = $before . $title . $after;
        $title = esc_attr(strip_tags($title));

        if ( $echo )
                echo $title;
        else
                return $title;
}

/**
 * Retrieve post title.
 *
 * If the post is protected and the visitor is not an admin, then "Protected"
 * will be displayed before the post title. If the post is private, then
 * "Private" will be located before the post title.
 *
 * @since 0.71
 *
 * @param int $id Optional. Post ID.
 * @return string
 */
function get_the_title( $id = 0 ) {
        $post = &get_post($id);

        $title = isset($post->post_title) ? $post->post_title : '';
        $id = isset($post->ID) ? $post->ID : (int) $id;

        if ( !is_admin() ) {
                if ( !empty($post->post_password) ) {
                        $protected_title_format = apply_filters('protected_title_format', __('Protected: %s'));
                        $title = sprintf($protected_title_format, $title);
                } else if ( isset($post->post_status) && 'private' == $post->post_status ) {
                        $private_title_format = apply_filters('private_title_format', __('Private: %s'));
                        $title = sprintf($private_title_format, $title);
                }
        }
        return apply_filters( 'the_title', $title, $id );
}

/**
 * Display the Post Global Unique Identifier (guid).
 *
 * The guid will appear to be a link, but should not be used as an link to the
 * post. The reason you should not use it as a link, is because of moving the
 * blog across domains.
 *
 * Url is escaped to make it xml safe
 *
 * @since 1.5.0
 *
 * @param int $id Optional. Post ID.
 */
function the_guid( $id = 0 ) {
        echo esc_url( get_the_guid( $id ) );
}

/**
 * Retrieve the Post Global Unique Identifier (guid).
 *
 * The guid will appear to be a link, but should not be used as an link to the
 * post. The reason you should not use it as a link, is because of moving the
 * blog across domains.
 *
 * @since 1.5.0
 *
 * @param int $id Optional. Post ID.
 * @return string
 */
function get_the_guid( $id = 0 ) {
        $post = &get_post($id);

        return apply_filters('get_the_guid', $post->guid);
}

/**
 * Display the post content.
 *
 * @since 0.71
 *
 * @param string $more_link_text Optional. Content for when there is more text.
 * @param string $stripteaser Optional. Teaser content before the more text.
 */
function the_content($more_link_text = null, $stripteaser = 0) {
        $content = get_the_content($more_link_text, $stripteaser);
        $content = apply_filters('the_content', $content);
        $content = str_replace(']]>', ']]&gt;', $content);
        echo $content;
}

/**
 * Retrieve the post content.
 *
 * @since 0.71
 *
 * @param string $more_link_text Optional. Content for when there is more text.
 * @param string $stripteaser Optional. Teaser content before the more text.
 * @return string
 */
function get_the_content($more_link_text = null, $stripteaser = 0) {
        global $id, $post, $more, $page, $pages, $multipage, $preview;

        if ( null === $more_link_text )
                $more_link_text = __( '(more...)' );

        $output = '';
        $hasTeaser = false;

        // If post password required and it doesn't match the cookie.
        if ( post_password_required($post) ) {
                $output = get_the_password_form();
                return $output;
        }

        if ( $page > count($pages) ) // if the requested page doesn't exist
                $page = count($pages); // give them the highest numbered page that DOES exist

        $content = $pages[$page-1];
        if ( preg_match('/<!--more(.*?)?-->/', $content, $matches) ) {
                $content = explode($matches[0], $content, 2);
                if ( !empty($matches[1]) && !empty($more_link_text) )
                        $more_link_text = strip_tags(wp_kses_no_null(trim($matches[1])));

                $hasTeaser = true;
        } else {
                $content = array($content);
        }
        if ( (false !== strpos($post->post_content, '<!--noteaser-->') && ((!$multipage) || ($page==1))) )
                $stripteaser = 1;
        $teaser = $content[0];
        if ( ($more) && ($stripteaser) && ($hasTeaser) )
                $teaser = '';
        $output .= $teaser;
        if ( count($content) > 1 ) {
                if ( $more ) {
                        $output .= '<span id="more-' . $id . '"></span>' . $content[1];
                } else {
                        if ( ! empty($more_link_text) )
                                $output .= apply_filters( 'the_content_more_link', ' <a href="' . get_permalink() . "#more-$id\" class=\"more-link\">$more_link_text</a>", $more_link_text );
                        $output = force_balance_tags($output);
                }

        }
        if ( $preview ) // preview fix for javascript bug with foreign languages
                $output =       preg_replace_callback('/\%u([0-9A-F]{4})/', create_function('$match', 'return "&#" . base_convert($match[1], 16, 10) . ";";'), $output);

        return $output;
}

/**
 * Display the post excerpt.
 *
 * @since 0.71
 * @uses apply_filters() Calls 'the_excerpt' hook on post excerpt.
 */
function the_excerpt() {
        echo apply_filters('the_excerpt', get_the_excerpt());
}

/**
 * Retrieve the post excerpt.
 *
 * @since 0.71
 *
 * @param mixed $deprecated Not used.
 * @return string
 */
function get_the_excerpt( $deprecated = '' ) {
        if ( !empty( $deprecated ) )
                _deprecated_argument( __FUNCTION__, '2.3' );

        global $post;
        $output = $post->post_excerpt;
        if ( post_password_required($post) ) {
                $output = __('There is no excerpt because this is a protected post.');
                return $output;
        }

        return apply_filters('get_the_excerpt', $output);
}

/**
 * Whether post has excerpt.
 *
 * @since 2.3.0
 *
 * @param int $id Optional. Post ID.
 * @return bool
 */
function has_excerpt( $id = 0 ) {
        $post = &get_post( $id );
        return ( !empty( $post->post_excerpt ) );
}

/**
 * Display the classes for the post div.
 *
 * @since 2.7.0
 *
 * @param string|array $class One or more classes to add to the class list.
 * @param int $post_id An optional post ID.
 */
function post_class( $class = '', $post_id = null ) {
        // Separates classes with a single space, collates classes for post DIV
        echo 'class="' . join( ' ', get_post_class( $class, $post_id ) ) . '"';
}

/**
 * Retrieve the classes for the post div as an array.
 *
 * The class names are add are many. If the post is a sticky, then the 'sticky'
 * class name. The class 'hentry' is always added to each post. For each
 * category, the class will be added with 'category-' with category slug is
 * added. The tags are the same way as the categories with 'tag-' before the tag
 * slug. All classes are passed through the filter, 'post_class' with the list
 * of classes, followed by $class parameter value, with the post ID as the last
 * parameter.
 *
 * @since 2.7.0
 *
 * @param string|array $class One or more classes to add to the class list.
 * @param int $post_id An optional post ID.
 * @return array Array of classes.
 */
function get_post_class( $class = '', $post_id = null ) {
        $post = get_post($post_id);

        $classes = array();

        if ( empty($post) )
                return $classes;

        $classes[] = 'post-' . $post->ID;
        $classes[] = $post->post_type;
        $classes[] = 'type-' . $post->post_type;

        // sticky for Sticky Posts
        if ( is_sticky($post->ID) && is_home() && !is_paged() )
                $classes[] = 'sticky';

        // hentry for hAtom compliace
        $classes[] = 'hentry';

        // Categories
        foreach ( (array) get_the_category($post->ID) as $cat ) {
                if ( empty($cat->slug ) )
                        continue;
                $classes[] = 'category-' . sanitize_html_class($cat->slug, $cat->cat_ID);
        }

        // Tags
        foreach ( (array) get_the_tags($post->ID) as $tag ) {
                if ( empty($tag->slug ) )
                        continue;
                $classes[] = 'tag-' . sanitize_html_class($tag->slug, $tag->term_id);
        }

        if ( !empty($class) ) {
                if ( !is_array( $class ) )
                        $class = preg_split('#\s+#', $class);
                $classes = array_merge($classes, $class);
        }

        $classes = array_map('esc_attr', $classes);

        return apply_filters('post_class', $classes, $class, $post->ID);
}

/**
 * Display the classes for the body element.
 *
 * @since 2.8.0
 *
 * @param string|array $class One or more classes to add to the class list.
 */
function body_class( $class = '' ) {
        // Separates classes with a single space, collates classes for body element
        echo 'class="' . join( ' ', get_body_class( $class ) ) . '"';
}

/**
 * Retrieve the classes for the body element as an array.
 *
 * @since 2.8.0
 *
 * @param string|array $class One or more classes to add to the class list.
 * @return array Array of classes.
 */
function get_body_class( $class = '' ) {
        global $wp_query, $wpdb;

        $classes = array();

        if ( is_rtl() )
                $classes[] = 'rtl';

        if ( is_front_page() )
                $classes[] = 'home';
        if ( is_home() )
                $classes[] = 'blog';
        if ( is_archive() )
                $classes[] = 'archive';
        if ( is_date() )
                $classes[] = 'date';
        if ( is_search() )
                $classes[] = 'search';
        if ( is_paged() )
                $classes[] = 'paged';
        if ( is_attachment() )
                $classes[] = 'attachment';
        if ( is_404() )
                $classes[] = 'error404';

        if ( is_single() ) {
                $post_id = $wp_query->get_queried_object_id();
                $post = $wp_query->get_queried_object();

                $classes[] = 'single';
                $classes[] = 'single-' . sanitize_html_class($post->post_type, $post_id);
                $classes[] = 'postid-' . $post_id;

                if ( is_attachment() ) {
                        $mime_type = get_post_mime_type($post_id);
                        $mime_prefix = array( 'application/', 'image/', 'text/', 'audio/', 'video/', 'music/' );
                        $classes[] = 'attachmentid-' . $post_id;
                        $classes[] = 'attachment-' . str_replace( $mime_prefix, '', $mime_type );
                }
        } elseif ( is_archive() ) {
                if ( is_author() ) {
                        $author = $wp_query->get_queried_object();
                        $classes[] = 'author';
                        $classes[] = 'author-' . sanitize_html_class( $author->user_nicename , $author->ID );
                } elseif ( is_category() ) {
                        $cat = $wp_query->get_queried_object();
                        $classes[] = 'category';
                        $classes[] = 'category-' . sanitize_html_class( $cat->slug, $cat->cat_ID );
                } elseif ( is_tag() ) {
                        $tags = $wp_query->get_queried_object();
                        $classes[] = 'tag';
                        $classes[] = 'tag-' . sanitize_html_class( $tags->slug, $tags->term_id );
                }
        } elseif ( is_page() ) {
                $classes[] = 'page';

                $page_id = $wp_query->get_queried_object_id();

                $post = get_page($page_id);

                $classes[] = 'page-id-' . $page_id;

                if ( $wpdb->get_var( $wpdb->prepare("SELECT ID FROM $wpdb->posts WHERE post_parent = %d AND post_type = 'page' AND post_status = 'publish' LIMIT 1", $page_id) ) )
                        $classes[] = 'page-parent';

                if ( $post->post_parent ) {
                        $classes[] = 'page-child';
                        $classes[] = 'parent-pageid-' . $post->post_parent;
                }
                if ( is_page_template() ) {
                        $classes[] = 'page-template';
                        $classes[] = 'page-template-' . sanitize_html_class( str_replace( '.', '-', get_post_meta( $page_id, '_wp_page_template', true ) ), '' );
                }
        } elseif ( is_search() ) {
                if ( !empty( $wp_query->posts ) )
                        $classes[] = 'search-results';
                else
                        $classes[] = 'search-no-results';
        }

        if ( is_user_logged_in() )
                $classes[] = 'logged-in';

        $page = $wp_query->get( 'page' );

        if ( !$page || $page < 2)
                $page = $wp_query->get( 'paged' );

        if ( $page && $page > 1 ) {
                $classes[] = 'paged-' . $page;

                if ( is_single() )
                        $classes[] = 'single-paged-' . $page;
                elseif ( is_page() )
                        $classes[] = 'page-paged-' . $page;
                elseif ( is_category() )
                        $classes[] = 'category-paged-' . $page;
                elseif ( is_tag() )
                        $classes[] = 'tag-paged-' . $page;
                elseif ( is_date() )
                        $classes[] = 'date-paged-' . $page;
                elseif ( is_author() )
                        $classes[] = 'author-paged-' . $page;
                elseif ( is_search() )
                        $classes[] = 'search-paged-' . $page;
        }

        if ( !empty( $class ) ) {
                if ( !is_array( $class ) )
                        $class = preg_split( '#\s+#', $class );
                $classes = array_merge( $classes, $class );
        }

        $classes = array_map( 'esc_attr', $classes );

        return apply_filters( 'body_class', $classes, $class );
}

/**
 * Whether post requires password and correct password has been provided.
 *
 * @since 2.7.0
 *
 * @param int|object $post An optional post.  Global $post used if not provided.
 * @return bool false if a password is not required or the correct password cookie is present, true otherwise.
 */
function post_password_required( $post = null ) {
        $post = get_post($post);

        if ( empty($post->post_password) )
                return false;

        if ( !isset($_COOKIE['wp-postpass_' . COOKIEHASH]) )
                return true;

        if ( $_COOKIE['wp-postpass_' . COOKIEHASH] != $post->post_password )
                return true;

        return false;
}

/**
 * Display "sticky" CSS class, if a post is sticky.
 *
 * @since 2.7.0
 *
 * @param int $post_id An optional post ID.
 */
function sticky_class( $post_id = null ) {
        if ( !is_sticky($post_id) )
                return;

        echo " sticky";
}

/**
 * Page Template Functions for usage in Themes
 *
 * @package WordPress
 * @subpackage Template
 */

/**
 * The formatted output of a list of pages.
 *
 * Displays page links for paginated posts (i.e. includes the <!--nextpage-->.
 * Quicktag one or more times). This tag must be within The Loop.
 *
 * The defaults for overwriting are:
 * 'next_or_number' - Default is 'number' (string). Indicates whether page
 *      numbers should be used. Valid values are number and next.
 * 'nextpagelink' - Default is 'Next Page' (string). Text for link to next page.
 *      of the bookmark.
 * 'previouspagelink' - Default is 'Previous Page' (string). Text for link to
 *      previous page, if available.
 * 'pagelink' - Default is '%' (String).Format string for page numbers. The % in
 *      the parameter string will be replaced with the page number, so Page %
 *      generates "Page 1", "Page 2", etc. Defaults to %, just the page number.
 * 'before' - Default is '<p> Pages:' (string). The html or text to prepend to
 *      each bookmarks.
 * 'after' - Default is '</p>' (string). The html or text to append to each
 *      bookmarks.
 * 'link_before' - Default is '' (string). The html or text to prepend to each
 *      Pages link inside the <a> tag. Also prepended to the current item, which
 *      is not linked.
 * 'link_after' - Default is '' (string). The html or text to append to each
 *      Pages link inside the <a> tag. Also appended to the current item, which
 *      is not linked.
 *
 * @since 1.2.0
 * @access private
 *
 * @param string|array $args Optional. Overwrite the defaults.
 * @return string Formatted output in HTML.
 */
function wp_link_pages($args = '') {
        $defaults = array(
                'before' => '<p>' . __('Pages:'), 'after' => '</p>',
                'link_before' => '', 'link_after' => '',
                'next_or_number' => 'number', 'nextpagelink' => __('Next page'),
                'previouspagelink' => __('Previous page'), 'pagelink' => '%',
                'echo' => 1
        );

        $r = wp_parse_args( $args, $defaults );
        $r = apply_filters( 'wp_link_pages_args', $r );
        extract( $r, EXTR_SKIP );

        global $post, $page, $numpages, $multipage, $more, $pagenow;

        $output = '';
        if ( $multipage ) {
                if ( 'number' == $next_or_number ) {
                        $output .= $before;
                        for ( $i = 1; $i < ($numpages+1); $i = $i + 1 ) {
                                $j = str_replace('%',$i,$pagelink);
                                $output .= ' ';
                                if ( ($i != $page) || ((!$more) && ($page==1)) ) {
                                        if ( 1 == $i ) {
                                                $output .= '<a href="' . get_permalink() . '">';
                                        } else {
                                                if ( '' == get_option('permalink_structure') || in_array($post->post_status, array('draft', 'pending')) )
                                                        $output .= '<a href="' . add_query_arg('page', $i, get_permalink()) . '">';
                                                elseif ( 'page' == get_option('show_on_front') && get_option('page_on_front') == $post->ID )
                                                        $output .= '<a href="' . trailingslashit(get_permalink()) . user_trailingslashit('page/' . $i, 'single_paged'). '">';
                                                else
                                                        $output .= '<a href="' . trailingslashit(get_permalink()) . user_trailingslashit($i, 'single_paged') . '">';
                                        }

                                }
                                $output .= $link_before;
                                $output .= $j;
                                $output .= $link_after;
                                if ( ($i != $page) || ((!$more) && ($page==1)) )
                                        $output .= '</a>';
                        }
                        $output .= $after;
                } else {
                        if ( $more ) {
                                $output .= $before;
                                $i = $page - 1;
                                if ( $i && $more ) {
                                        if ( 1 == $i ) {
                                                $output .= '<a href="' . get_permalink() . '">';
                                        } else {
                                                if ( '' == get_option('permalink_structure') || in_array($post->post_status, array('draft', 'pending')) )
                                                        $output .= '<a href="' . add_query_arg('page', $i, get_permalink()) . '">';
                                                elseif ( 'page' == get_option('show_on_front') && get_option('page_on_front') == $post->ID )
                                                        $output .= '<a href="' . trailingslashit(get_permalink()) . user_trailingslashit('page/' . $i, 'single_paged'). '">';
                                                else
                                                        $output .= '<a href="' . trailingslashit(get_permalink()) . user_trailingslashit($i, 'single_paged') . '">';
                                        }
                                        $output .= $link_before. $previouspagelink . $link_after . '</a>';
                                }
                                $i = $page + 1;
                                if ( $i <= $numpages && $more ) {
                                        if ( 1 == $i ) {
                                                $output .= '<a href="' . get_permalink() . '">';
                                        } else {
                                                if ( '' == get_option('permalink_structure') || in_array($post->post_status, array('draft', 'pending')) )
                                                        $output .= '<a href="' . add_query_arg('page', $i, get_permalink()) . '">';
                                                elseif ( 'page' == get_option('show_on_front') && get_option('page_on_front') == $post->ID )
                                                        $output .= '<a href="' . trailingslashit(get_permalink()) . user_trailingslashit('page/' . $i, 'single_paged'). '">';
                                                else
                                                        $output .= '<a href="' . trailingslashit(get_permalink()) . user_trailingslashit($i, 'single_paged') . '">';
                                        }
                                        $output .= $link_before. $nextpagelink . $link_after . '</a>';
                                }
                                $output .= $after;
                        }
                }
        }

        if ( $echo )
                echo $output;

        return $output;
}


//
// Post-meta: Custom per-post fields.
//

/**
 * Retrieve post custom meta data field.
 *
 * @since 1.5.0
 *
 * @param string $key Meta data key name.
 * @return bool|string|array Array of values or single value, if only one element exists. False will be returned if key does not exist.
 */
function post_custom( $key = '' ) {
        $custom = get_post_custom();

        if ( !isset( $custom[$key] ) )
                return false;
        elseif ( 1 == count($custom[$key]) )
                return $custom[$key][0];
        else
                return $custom[$key];
}

/**
 * Display list of post custom fields.
 *
 * @internal This will probably change at some point...
 * @since 1.2.0
 * @uses apply_filters() Calls 'the_meta_key' on list item HTML content, with key and value as separate parameters.
 */
function the_meta() {
        if ( $keys = get_post_custom_keys() ) {
                echo "<ul class='post-meta'>\n";
                foreach ( (array) $keys as $key ) {
                        $keyt = trim($key);
                        if ( '_' == $keyt{0} )
                                continue;
                        $values = array_map('trim', get_post_custom_values($key));
                        $value = implode($values,', ');
                        echo apply_filters('the_meta_key', "<li><span class='post-meta-key'>$key:</span> $value</li>\n", $key, $value);
                }
                echo "</ul>\n";
        }
}

//
// Pages
//

/**
 * Retrieve or display list of pages as a dropdown (select list).
 *
 * @since 2.1.0
 *
 * @param array|string $args Optional. Override default arguments.
 * @return string HTML content, if not displaying.
 */
function wp_dropdown_pages($args = '') {
        $defaults = array(
                'depth' => 0, 'child_of' => 0,
                'selected' => 0, 'echo' => 1,
                'name' => 'page_id', 'id' => '',
                'show_option_none' => '', 'show_option_no_change' => '',
                'option_none_value' => ''
        );

        $r = wp_parse_args( $args, $defaults );
        extract( $r, EXTR_SKIP );

        $pages = get_pages($r);
        $output = '';
        $name = esc_attr($name);
        // Back-compat with old system where both id and name were based on $name argument
        if ( empty($id) )
                $id = $name;

        if ( ! empty($pages) ) {
                $output = "<select name=\"$name\" id=\"$id\">\n";
                if ( $show_option_no_change )
                        $output .= "\t<option value=\"-1\">$show_option_no_change</option>";
                if ( $show_option_none )
                        $output .= "\t<option value=\"" . esc_attr($option_none_value) . "\">$show_option_none</option>\n";
                $output .= walk_page_dropdown_tree($pages, $depth, $r);
                $output .= "</select>\n";
        }

        $output = apply_filters('wp_dropdown_pages', $output);

        if ( $echo )
                echo $output;

        return $output;
}

/**
 * Retrieve or display list of pages in list (li) format.
 *
 * @since 1.5.0
 *
 * @param array|string $args Optional. Override default arguments.
 * @return string HTML content, if not displaying.
 */
function wp_list_pages($args = '') {
        $defaults = array(
                'depth' => 0, 'show_date' => '',
                'date_format' => get_option('date_format'),
                'child_of' => 0, 'exclude' => '',
                'title_li' => __('Pages'), 'echo' => 1,
                'authors' => '', 'sort_column' => 'menu_order, post_title',
                'link_before' => '', 'link_after' => '', 'walker' => '',
        );

        $r = wp_parse_args( $args, $defaults );
        extract( $r, EXTR_SKIP );

        $output = '';
        $current_page = 0;

        // sanitize, mostly to keep spaces out
        $r['exclude'] = preg_replace('/[^0-9,]/', '', $r['exclude']);

        // Allow plugins to filter an array of excluded pages (but don't put a nullstring into the array)
        $exclude_array = ( $r['exclude'] ) ? explode(',', $r['exclude']) : array();
        $r['exclude'] = implode( ',', apply_filters('wp_list_pages_excludes', $exclude_array) );

        // Query pages.
        $r['hierarchical'] = 0;
        $pages = get_pages($r);

        if ( !empty($pages) ) {
                if ( $r['title_li'] )
                        $output .= '<li class="pagenav">' . $r['title_li'] . '<ul>';

                global $wp_query;
                if ( is_page() || is_attachment() || $wp_query->is_posts_page )
                        $current_page = $wp_query->get_queried_object_id();
                $output .= walk_page_tree($pages, $r['depth'], $current_page, $r);

                if ( $r['title_li'] )
                        $output .= '</ul></li>';
        }

        $output = apply_filters('wp_list_pages', $output, $r);

        if ( $r['echo'] )
                echo $output;
        else
                return $output;
}

/**
 * Display or retrieve list of pages with optional home link.
 *
 * The arguments are listed below and part of the arguments are for {@link
 * wp_list_pages()} function. Check that function for more info on those
 * arguments.
 *
 * <ul>
 * <li><strong>sort_column</strong> - How to sort the list of pages. Defaults
 * to page title. Use column for posts table.</li>
 * <li><strong>menu_class</strong> - Class to use for the div ID which contains
 * the page list. Defaults to 'menu'.</li>
 * <li><strong>echo</strong> - Whether to echo list or return it. Defaults to
 * echo.</li>
 * <li><strong>link_before</strong> - Text before show_home argument text.</li>
 * <li><strong>link_after</strong> - Text after show_home argument text.</li>
 * <li><strong>show_home</strong> - If you set this argument, then it will
 * display the link to the home page. The show_home argument really just needs
 * to be set to the value of the text of the link.</li>
 * </ul>
 *
 * @since 2.7.0
 *
 * @param array|string $args
 */
function wp_page_menu( $args = array() ) {
        $defaults = array('sort_column' => 'menu_order, post_title', 'menu_class' => 'menu', 'echo' => true, 'link_before' => '', 'link_after' => '');
        $args = wp_parse_args( $args, $defaults );
        $args = apply_filters( 'wp_page_menu_args', $args );

        $menu = '';

        $list_args = $args;

        // Show Home in the menu
        if ( ! empty($args['show_home']) ) {
                if ( true === $args['show_home'] || '1' === $args['show_home'] || 1 === $args['show_home'] )
                        $text = __('Home');
                else
                        $text = $args['show_home'];
                $class = '';
                if ( is_front_page() && !is_paged() )
                        $class = 'class="current_page_item"';
                $menu .= '<li ' . $class . '><a href="' . home_url( '/' ) . '" title="' . esc_attr($text) . '">' . $args['link_before'] . $text . $args['link_after'] . '</a></li>';
                // If the front page is a page, add it to the exclude list
                if (get_option('show_on_front') == 'page') {
                        if ( !empty( $list_args['exclude'] ) ) {
                                $list_args['exclude'] .= ',';
                        } else {
                                $list_args['exclude'] = '';
                        }
                        $list_args['exclude'] .= get_option('page_on_front');
                }
        }

        $list_args['echo'] = false;
        $list_args['title_li'] = '';
        $menu .= str_replace( array( "\r", "\n", "\t" ), '', wp_list_pages($list_args) );

        if ( $menu )
                $menu = '<ul>' . $menu . '</ul>';

        $menu = '<div class="' . esc_attr($args['menu_class']) . '">' . $menu . "</div>\n";
        $menu = apply_filters( 'wp_page_menu', $menu, $args );
        if ( $args['echo'] )
                echo $menu;
        else
                return $menu;
}

//
// Page helpers
//

/**
 * Retrieve HTML list content for page list.
 *
 * @uses Walker_Page to create HTML list content.
 * @since 2.1.0
 * @see Walker_Page::walk() for parameters and return description.
 */
function walk_page_tree($pages, $depth, $current_page, $r) {
        if ( empty($r['walker']) )
                $walker = new Walker_Page;
        else
                $walker = $r['walker'];

        $args = array($pages, $depth, $r, $current_page);
        return call_user_func_array(array(&$walker, 'walk'), $args);
}

/**
 * Retrieve HTML dropdown (select) content for page list.
 *
 * @uses Walker_PageDropdown to create HTML dropdown content.
 * @since 2.1.0
 * @see Walker_PageDropdown::walk() for parameters and return description.
 */
function walk_page_dropdown_tree() {
        $args = func_get_args();
        if ( empty($args[2]['walker']) ) // the user's options are the third parameter
                $walker = new Walker_PageDropdown;
        else
                $walker = $args[2]['walker'];

        return call_user_func_array(array(&$walker, 'walk'), $args);
}

//
// Attachments
//

/**
 * Display an attachment page link using an image or icon.
 *
 * @since 2.0.0
 *
 * @param int $id Optional. Post ID.
 * @param bool $fullsize Optional, default is false. Whether to use full size.
 * @param bool $deprecated Deprecated. Not used.
 * @param bool $permalink Optional, default is false. Whether to include permalink.
 */
function the_attachment_link( $id = 0, $fullsize = false, $deprecated = false, $permalink = false ) {
        if ( !empty( $deprecated ) )
                _deprecated_argument( __FUNCTION__, '2.5' );

        if ( $fullsize )
                echo wp_get_attachment_link($id, 'full', $permalink);
        else
                echo wp_get_attachment_link($id, 'thumbnail', $permalink);
}

/**
 * Retrieve an attachment page link using an image or icon, if possible.
 *
 * @since 2.5.0
 * @uses apply_filters() Calls 'wp_get_attachment_link' filter on HTML content with same parameters as function.
 *
 * @param int $id Optional. Post ID.
 * @param string $size Optional, default is 'thumbnail'. Size of image, either array or string.
 * @param bool $permalink Optional, default is false. Whether to add permalink to image.
 * @param bool $icon Optional, default is false. Whether to include icon.
 * @param string $text Optional, default is false. If string, then will be link text.
 * @return string HTML content.
 */
function wp_get_attachment_link($id = 0, $size = 'thumbnail', $permalink = false, $icon = false, $text = false) {
        $id = intval($id);
        $_post = & get_post( $id );

        if ( ('attachment' != $_post->post_type) || !$url = wp_get_attachment_url($_post->ID) )
                return __('Missing Attachment');

        if ( $permalink )
                $url = get_attachment_link($_post->ID);

        $post_title = esc_attr($_post->post_title);

        if ( $text ) {
                $link_text = esc_attr($text);
        } elseif ( ( is_int($size) && $size != 0 ) or ( is_string($size) && $size != 'none' ) or $size != false ) {
                $link_text = wp_get_attachment_image($id, $size, $icon);
        } else {
                $link_text = '';
        }

        if( trim($link_text) == '' )
                $link_text = $_post->post_title;

        return apply_filters( 'wp_get_attachment_link', "<a href='$url' title='$post_title'>$link_text</a>", $id, $size, $permalink, $icon, $text );
}

/**
 * Wrap attachment in <<p>> element before content.
 *
 * @since 2.0.0
 * @uses apply_filters() Calls 'prepend_attachment' hook on HTML content.
 *
 * @param string $content
 * @return string
 */
function prepend_attachment($content) {
        global $post;

        if ( empty($post->post_type) || $post->post_type != 'attachment' )
                return $content;

        $p = '<p class="attachment">';
        // show the medium sized image representation of the attachment if available, and link to the raw file
        $p .= wp_get_attachment_link(0, 'medium', false);
        $p .= '</p>';
        $p = apply_filters('prepend_attachment', $p);

        return "$p\n$content";
}

//
// Misc
//

/**
 * Retrieve protected post password form content.
 *
 * @since 1.0.0
 * @uses apply_filters() Calls 'the_password_form' filter on output.
 *
 * @return string HTML content for password form for password protected post.
 */
function get_the_password_form() {
        global $post;
        $label = 'pwbox-'.(empty($post->ID) ? rand() : $post->ID);
        $output = '<form action="' . get_option('siteurl') . '/wp-pass.php" method="post">
        <p>' . __("This post is password protected. To view it please enter your password below:") . '</p>
        <p><label for="' . $label . '">' . __("Password:") . ' <input name="post_password" id="' . $label . '" type="password" size="20" /></label> <input type="submit" name="Submit" value="' . esc_attr__("Submit") . '" /></p>
        </form>
        ';
        return apply_filters('the_password_form', $output);
}

/**
 * Whether currently in a page template.
 *
 * This template tag allows you to determine if you are in a page template.
 * You can optionally provide a template name and then the check will be
 * specific to that template.
 *
 * @since 2.5.0
 * @uses $wp_query
 *
 * @param string $template The specific template name if specific matching is required.
 * @return bool False on failure, true if success.
 */
function is_page_template($template = '') {
        if (!is_page()) {
                return false;
        }

        global $wp_query;

        $page = $wp_query->get_queried_object();
        $custom_fields = get_post_custom_values('_wp_page_template',$page->ID);
        $page_template = $custom_fields[0];

        // We have no argument passed so just see if a page_template has been specified
        if ( empty( $template ) ) {
                if (!empty( $page_template ) ) {
                        return true;
                }
        } elseif ( $template == $page_template) {
                return true;
        }

        return false;
}

/**
 * Retrieve formatted date timestamp of a revision (linked to that revisions's page).
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses date_i18n()
 *
 * @param int|object $revision Revision ID or revision object.
 * @param bool $link Optional, default is true. Link to revisions's page?
 * @return string i18n formatted datetimestamp or localized 'Current Revision'.
 */
function wp_post_revision_title( $revision, $link = true ) {
        if ( !$revision = get_post( $revision ) )
                return $revision;

        if ( !in_array( $revision->post_type, array( 'post', 'page', 'revision' ) ) )
                return false;

        /* translators: revision date format, see http://php.net/date */
        $datef = _x( 'j F, Y @ G:i', 'revision date format');
        /* translators: 1: date */
        $autosavef = __( '%1$s [Autosave]' );
        /* translators: 1: date */
        $currentf  = __( '%1$s [Current Revision]' );

        $date = date_i18n( $datef, strtotime( $revision->post_modified ) );
        if ( $link && current_user_can( 'edit_post', $revision->ID ) && $link = get_edit_post_link( $revision->ID ) )
                $date = "<a href='$link'>$date</a>";

        if ( !wp_is_post_revision( $revision ) )
                $date = sprintf( $currentf, $date );
        elseif ( wp_is_post_autosave( $revision ) )
                $date = sprintf( $autosavef, $date );

        return $date;
}

/**
 * Display list of a post's revisions.
 *
 * Can output either a UL with edit links or a TABLE with diff interface, and
 * restore action links.
 *
 * Second argument controls parameters:
 *   (bool)   parent : include the parent (the "Current Revision") in the list.
 *   (string) format : 'list' or 'form-table'.  'list' outputs UL, 'form-table'
 *                     outputs TABLE with UI.
 *   (int)    right  : what revision is currently being viewed - used in
 *                     form-table format.
 *   (int)    left   : what revision is currently being diffed against right -
 *                     used in form-table format.
 *
 * @package WordPress
 * @subpackage Post_Revisions
 * @since 2.6.0
 *
 * @uses wp_get_post_revisions()
 * @uses wp_post_revision_title()
 * @uses get_edit_post_link()
 * @uses get_the_author_meta()
 *
 * @todo split into two functions (list, form-table) ?
 *
 * @param int|object $post_id Post ID or post object.
 * @param string|array $args See description {@link wp_parse_args()}.
 * @return null
 */
function wp_list_post_revisions( $post_id = 0, $args = null ) {
        if ( !$post = get_post( $post_id ) )
                return;

        $defaults = array( 'parent' => false, 'right' => false, 'left' => false, 'format' => 'list', 'type' => 'all' );
        extract( wp_parse_args( $args, $defaults ), EXTR_SKIP );

        switch ( $type ) {
                case 'autosave' :
                        if ( !$autosave = wp_get_post_autosave( $post->ID ) )
                                return;
                        $revisions = array( $autosave );
                        break;
                case 'revision' : // just revisions - remove autosave later
                case 'all' :
                default :
                        if ( !$revisions = wp_get_post_revisions( $post->ID ) )
                                return;
                        break;
        }

        /* translators: post revision: 1: when, 2: author name */
        $titlef = _x( '%1$s by %2$s', 'post revision' );

        if ( $parent )
                array_unshift( $revisions, $post );

        $rows = '';
        $class = false;
        $can_edit_post = current_user_can( 'edit_post', $post->ID );
        foreach ( $revisions as $revision ) {
                if ( !current_user_can( 'read_post', $revision->ID ) )
                        continue;
                if ( 'revision' === $type && wp_is_post_autosave( $revision ) )
                        continue;

                $date = wp_post_revision_title( $revision );
                $name = get_the_author_meta( 'display_name', $revision->post_author );

                if ( 'form-table' == $format ) {
                        if ( $left )
                                $left_checked = $left == $revision->ID ? ' checked="checked"' : '';
                        else
                                $left_checked = $right_checked ? ' checked="checked"' : ''; // [sic] (the next one)
                        $right_checked = $right == $revision->ID ? ' checked="checked"' : '';

                        $class = $class ? '' : " class='alternate'";

                        if ( $post->ID != $revision->ID && $can_edit_post )
                                $actions = '<a href="' . wp_nonce_url( add_query_arg( array( 'revision' => $revision->ID, 'action' => 'restore' ) ), "restore-post_$post->ID|$revision->ID" ) . '">' . __( 'Restore' ) . '</a>';
                        else
                                $actions = '';

                        $rows .= "<tr$class>\n";
                        $rows .= "\t<th style='white-space: nowrap' scope='row'><input type='radio' name='left' value='$revision->ID'$left_checked /></th>\n";
                        $rows .= "\t<th style='white-space: nowrap' scope='row'><input type='radio' name='right' value='$revision->ID'$right_checked /></th>\n";
                        $rows .= "\t<td>$date</td>\n";
                        $rows .= "\t<td>$name</td>\n";
                        $rows .= "\t<td class='action-links'>$actions</td>\n";
                        $rows .= "</tr>\n";
                } else {
                        $title = sprintf( $titlef, $date, $name );
                        $rows .= "\t<li>$title</li>\n";
                }
        }

        if ( 'form-table' == $format ) : ?>

<form action="revision.php" method="get">

<div class="tablenav">
        <div class="alignleft">
                <input type="submit" class="button-secondary" value="<?php esc_attr_e( 'Compare Revisions' ); ?>" />
                <input type="hidden" name="action" value="diff" />
                <input type="hidden" name="post_type" value="<?php echo esc_attr($post->post_type); ?>" />
        </div>
</div>

<br class="clear" />

<table class="widefat post-revisions" cellspacing="0" id="post-revisions">
        <col />
        <col />
        <col style="width: 33%" />
        <col style="width: 33%" />
        <col style="width: 33%" />
<thead>
<tr>
        <th scope="col"><?php /* translators: column name in revisons */ _ex( 'Old', 'revisions column name' ); ?></th>
        <th scope="col"><?php /* translators: column name in revisons */ _ex( 'New', 'revisions column name' ); ?></th>
        <th scope="col"><?php /* translators: column name in revisons */ _ex( 'Date Created', 'revisions column name' ); ?></th>
        <th scope="col"><?php _e( 'Author' ); ?></th>
        <th scope="col" class="action-links"><?php _e( 'Actions' ); ?></th>
</tr>
</thead>
<tbody>

<?php echo $rows; ?>

</tbody>
</table>

</form>

<?php
        else :
                echo "<ul class='post-revisions'>\n";
                echo $rows;
                echo "</ul>";
        endif;

}