WordPress函数wp_count_posts()用法 获取各个类型的文章总数

描述：

获取各个类型的文章总数

用法：

<?php wp_count_posts( $type, $perm ); ?>

参数：

$type

(string) (可选) wp_posts 中文章的类型，用于核查哪种类型与post_type对应。默认post。

默认值: 'post'

$perm

(string) (可选) 如果该参数设置为'readable'并且用户已登录，则可将私密文章状态算入文章状态中。默认为empty string。

默认值: empty string

示例：

获取发表状态文章的计数
要获取已发表文章的状态类型，应先调用wp_count_posts()函数然后确查看“publish”属性。

<?php
$count_posts = wp_count_posts();
$published_posts = $count_posts->publish;
?>

源文件：

/**
* Count number of posts of a post type and if user has permissions to view.
*
* This function provides an efficient method of finding the amount of post's
* type a blog has. Another method is to count the amount of items in
* get_posts(), but that method has a lot of overhead with doing so. Therefore,
* when developing for 2.5+, use this function instead.
*
* The $perm parameter checks for 'readable' value and if the user can read
* private posts, it will display that for the user that is signed in.
*
* @since 2.5.0
*
* @global wpdb $wpdb
*
* @param string $type Optional. Post type to retrieve count. Default 'post'.
* @param string $perm Optional. 'readable' or empty. Default empty.
* @return object Number of posts for each status.
*/
function wp_count_posts( $type = 'post', $perm = '' ) {
global $wpdb;

if ( ! post_type_exists( $type ) )
return new stdClass;

$cache_key = _count_posts_cache_key( $type, $perm );

$counts = wp_cache_get( $cache_key, 'counts' );
if ( false !== $counts ) {
/** This filter is documented in wp-includes/post.php */
return apply_filters( 'wp_count_posts', $counts, $type, $perm );
}

$query = "SELECT post_status, COUNT( * ) AS num_posts FROM {$wpdb->posts} WHERE post_type = %s";
if ( 'readable' == $perm && is_user_logged_in() ) {
$post_type_object = get_post_type_object($type);
if ( ! current_user_can( $post_type_object->cap->read_private_posts ) ) {
$query .= $wpdb->prepare( " AND (post_status != 'private' OR ( post_author = %d AND post_status = 'private' ))",
get_current_user_id()
);
}
}
$query .= ' GROUP BY post_status';

$results = (array) $wpdb->get_results( $wpdb->prepare( $query, $type ), ARRAY_A );
$counts = array_fill_keys( get_post_stati(), 0 );

foreach ( $results as $row ) {
$counts[ $row['post_status'] ] = $row['num_posts'];
}

$counts = (object) $counts;
wp_cache_set( $cache_key, $counts, 'counts' );

/**
* Modify returned post counts by status for the current post type.
*
* @since 3.7.0
*
* @param object $counts An object containing the current post_type's post
* counts by status.
* @param string $type Post type.
* @param string $perm The permission to determine if the posts are 'readable'
* by the current user.
*/
return apply_filters( 'wp_count_posts', $counts, $type, $perm );
}