Question

我是新来的，也是PHP中的新东西..

只是想知道如何像在Wordpress中一样创建自己的灵活循环... 注意我不是在谈论wordpress ..我想在我自己的PHP应用程序上实现它...

让我们回顾WP，有一个类似的代码：

while (have_post() : thepost())// .. bla bla...

echo the_title();
echo the_content();

endwhile; // this is just an ilustration

你能弄清楚have_post（）或the_post（）如何与数据库交互，这样他们就可以循环..

感谢..

Answer 1

WordPress使用这些函数在迭代循环时修改的全局变量。 e.g：

var $posts = null;
var $post = null;
var $post_count = 0;
var $post_index = 0;

function have_post() {
    global $posts, $post_count, $post_index;

    $post_index = 0;

    // do a database call to retrieve the posts.
    $posts = mysql_query('select * from posts where ...');

    if ($posts) {
        $post_count = count($posts);
        return true;
    } else {
        $post_count = 0;
        return false;
    }
}

function thepost() {
    global $posts, $post, $post_count, $post_index;

    // make sure all the posts haven't already been looped through
    if ($post_index > $post_count) {
        return false;
    }

    // retrieve the post data for the current index
    $post = $posts[$post_index];

    // increment the index for the next time this method is called
    $post_index++;

    return $post;
}

function the_title() {
    global $post;
    return $post['title'];
}

function the_content() {
    global $post;
    return $post['content'];
}

我肯定会建议使用OOP样式编码而不是WordPress。这将保持变量在对象的实例中定义，而不是全局可访问。 e.g：

class Post {
    function __construct($title, $content) {
        $this->title = $title;
        $this->content = $content;
    }

    function getTitle() {
        return $title;
    }

    function getContent() {
        return $content;
    }
}

class Posts {
    var $postCount = 0;
    var $posts = null;

    function __construct($conditions) {
        $rs = mysql_query('select * from posts where $conditions...');

        if ($rs) {
            $this->postCount = count($rs);
            $this->posts = array();

            foreach ($rs as $row) {
                $this->posts[] = new Post($row['title'], $row['content']);
            }
        }
    }

    function getPostCount() {
        return $this->postCount;
    }

    function getPost($index) {
        return $this->posts[$index];
    }
}

Answer 2

您可以实施Iterator界面。

Answer 3

这个想法是使用全局范围变量，然后函数将修改这些变量：

// first define the global variables:
$post_index = 0;
$posts_count = 0;
$post = null;
$posts = null;
$connection = null;

$connection = new PDO('mysql:host=127.0.0.1;dbname=YOUR_DB', 'YOUR_DB_USERNAME', 'YOUR_DB_USER_PASSWORD', array(PDO::ATTR_FETCH_MODE => PDO::FETCH_ASSOC));

$query = $connection->query('SELECT * FROM posts');
$posts = $query->fetchAll();

$posts_count = count($posts); // or = $query->rowCount()

// now you create the functions that will deal with and change those variables

function have_posts()
{
    global $post_index, $posts_count, $posts, $post;
    // if posts found and if post_index < posts_count return true else return false
    if($posts && $post_index < $post_count)
        return true;

    else
        return false;
}

function the_post()
{
    global $post_count, $post_index, $posts, $post;

    if($post_index > $post_count)
        return false;
    // fetch the post of the current index
    $post = $posts[$post_index];

    // increment the $post_index so that the next call to this function grapes the next post
    $post_index++;
}

function get_ID()
{
    global $post;
    return $post['ID'];
}


function get_title()
{
    global $post;
    return $post['title'];
}

我希望有所帮助。

Answer 4

再次转到此问题：D

最后我得到了解决方案，

@Matt Huggins，我对你的代码进行了一些修改，现在它的工作......

$posts = $wpdb->get_results('SELECT * FROM my_table',OBJECT);
$post = null;
$post_count = 0;
$post_index = 0;

function have_post() {
    global $posts, $post_count, $post_index;

    if ($posts && ($post_index <= $post_count)){
        $post_count = count($posts);
        return true;
    }
    else {
        $post_count = 0;
        return false;
    }
}

function the_post() {
    global $posts, $post, $post_count, $post_index;

    // make sure all the posts haven't already been looped through
    if ($post_index > $post_count) {
        return false;
    }

    // retrieve the post data for the current index
    $post = $posts[$post_index+1];

    // increment the index for the next time this method is called
    $post_index++;
    return $post;

}

function the_title() {
    global $post;
    return $post->Title;
}

function the_content() {
    global $post;
    return $post->Content;
}

//and the output

if(have_post()) : while(have_post()) : the_post();
echo '<h2>'.the_title().'</h2>';
echo '<p>'.the_content().'</p>';
endwhile; endif;

非常感谢...... :)

如何像Wordpress Loop一样创建自己的循环？

4 个答案: