无法创建深层菜单

Question

我正在尝试创建一个深层菜单，所以我在我的数据库中定义了这个表结构：

id | parent | menu_order
15      0         0
22     15         0
26     15         0
30     15         0
47     22         0
49     22         0
51     22         0
68     26         0
69     26         0

我想要实现的是生成允许我正确设置menu_order 列的代码，在上面的示例中，最终结果应该是：

id | parent | menu_order
15     0          0
22     15         1
26     15         5
30     15         8
47     22         2
49     22         3
51     22         4
68     26         6
69     26         7

结果很容易理解，基本上22 有parent 15，所以menu_order 是1。相同的概念适用于22 的嵌套级别，即(47,49,51)。

其实我的代码是这样的：

<?php

$posts = [
    ['id' => 15, 'parent' => 0, 'menu_order' => 0],
    ['id' => 22, 'parent' => 15, 'menu_order' => 0],
    ['id' => 26, 'parent' => 15, 'menu_order' => 0],
    ['id' => 30, 'parent' => 15, 'menu_order' => 0],
    ['id' => 47, 'parent' => 22, 'menu_order' => 0],
    ['id' => 49, 'parent' => 22, 'menu_order' => 0],
    ['id' => 51, 'parent' => 22, 'menu_order' => 0],
    ['id' => 68, 'parent' => 26, 'menu_order' => 0],
    ['id' => 69, 'parent' => 26, 'menu_order' => 0],
];

$currOrder = -1;

 foreach ($posts as $key => $p) {

    $currOrder++;

    $test[] = [
        'id'    => $p['id'],
        'parent' => $p['parent'],
        'menu_order' => $currOrder
    ];

    hasChild($p['id'], $currOrder, $test);
}

    
function hasChild($postId, &$currOrder, $test)
{
    // get childs post
    $childs = $this->where('parent', $postId)
        ->get()
        ->getResult();

    foreach ($childs as $c) {

        $currOrder++;
        
        $test[] = [
            'id'    => $c['id'],
            'parent' => $c['parent'],
            'menu_order' => $currOrder
        ];

         // check nested levels
        if ($c->parent != 0) {
           hasChild($c['id'], $currOrder, $test);
        }
    }
}

问题是我得到了嵌套级别的重复帖子，而menu_order 完全搞砸了。我想我的逻辑过于复杂，有人可以帮我实现这个吗？

谢谢

Answer 1

有几种方法可以处理递归函数。我就是这样做的。

<?php
// example code

$posts = [
    ['id' => 15, 'parent' => 0, 'menu_order' => 0],
    ['id' => 22, 'parent' => 15, 'menu_order' => 0],
    ['id' => 26, 'parent' => 15, 'menu_order' => 0],
    ['id' => 30, 'parent' => 15, 'menu_order' => 0],
    ['id' => 47, 'parent' => 22, 'menu_order' => 0],
    ['id' => 49, 'parent' => 22, 'menu_order' => 0],
    ['id' => 51, 'parent' => 22, 'menu_order' => 0],
    ['id' => 68, 'parent' => 26, 'menu_order' => 0],
    ['id' => 69, 'parent' => 26, 'menu_order' => 0],
];


function recursePosts($pid, $order, $tally, $posts) {
    foreach($posts as $p) {
        if ($p['parent']===$pid) {
            $p['menu_order'] = $tally  ;
            $order['id'.$p['id']] = $p;
            $tally++;
            $o = recursePosts($p['id'], $order, $tally, $posts);  
            $tally = $o[1];
            $order = $o[0];
        }
        
    }
    return [$order, $tally];
}
$o =recursePosts(0, [], 0, $posts);
$order = $o[0];
ksort($order);
print_r(array_values($order));

https://www.tehplayground.com/uNY7Bn0VyDv6JIUS

还有PHP原生的RecursiveIterator