6

我有一个包含一堆类别的数据库，有些是孩子：

Array
(
    [0] => Array
        (
            [id] => 1
            [name] => Home Improvement
            [slug] => Home-Improvement
            [parent] => 
            [user_id] => 1
            [order] => 1
        )

    [1] => Array
        (
            [id] => 2
            [name] => Asbestos Abatement & Removal
            [slug] => Asbestos-Abatement-Removal
            [parent] => 1
            [user_id] => 1
            [order] => 8
        )

    [2] => Array
        (
            [id] => 3
            [name] => Asphalt & Asphalt Products
            [slug] => Asphalt-Asphalt-Products
            [parent] => 1
            [user_id] => 1
            [order] => 9
        )

    [3] => Array
        (
            [id] => 4
            [name] => Bathroom
            [slug] => Bathroom
            [parent] => 1
            [user_id] => 1
            [order] => 10
        )

    [4] => Array
        (
            [id] => 5
            [name] => Kitchen Cabinets
            [slug] => Kitchen-Cabinets
            [parent] => 1
            [user_id] => 1
            [order] => 11
        )

    [5] => Array
        (
            [id] => 6
            [name] => Ceilings
            [slug] => Ceilings
            [parent] => 1
            [user_id] => 1
            [order] => 12
        )

    [6] => Array
        (
            [id] => 7
            [name] => Cleaning
            [slug] => Cleaning
            [parent] => 1
            [user_id] => 1
            [order] => 13
        )

    [7] => Array
        (
            [id] => 8
            [name] => Closet Organizers & Accessories
            [slug] => Closet-Organizers-Accessories
            [parent] => 1
            [user_id] => 1
            [order] => 14
        )

    [8] => Array
        (
            [id] => 9
            [name] => Concrete
            [slug] => Concrete
            [parent] => 1
            [user_id] => 1
            [order] => 15
        )

    [9] => Array
        (
            [id] => 10
            [name] => Contractors & Service Providers
            [slug] => Contractors-Service-Providers
            [parent] => 1
            [user_id] => 1
            [order] => 16
        )

我试图输出的是这样的：

<ul>
    <li>Parent
        <ul>
            <li>Child</li>
        </ul>
    </li>
    <li>Parent with no Children</li>
</ul>

我正在尝试在 PHP 中构建递归树脚本，但我被卡住了。这是我到目前为止所拥有的。我被困在 else: 和 endif; 之间该怎么做。在 foreach 中。（我使用这种语法只是为了在这里更容易阅读。）有什么建议吗？

echo $this->categories->makeTree(0, $this->db->get('categories')->result_array());

public static function makeTree($parent, $array)
{
  if (!is_array($array)) return '';

  $output = '<ul>';

  foreach($array as $key => $value):
    if ($value['parent'] == $parent):
        $output .= '<li>';

        if ($value['parent'] == NULL):
            $output .= $value['name'];
        else:

        endif;
    endif;

    $output .= '</li>';
  endforeach;

  $output .= '</ul>';
  return $output;
}

编辑 1

尽管我在 foreach 循环中有一个数据库调用，但我能够让它工作，这可能不是最好的主意：

public function makeTree($parent, $array)
{
  if (!is_array($array)) return FALSE;

  $output = '<ul>';

  foreach($array as $key => $value):
    if ($value['parent'] == $parent):
        $output .= '<li>';

        if ($value['parent'] == NULL):
            $output .= $value['name'];

            $subcategories = ci()->db->get_where('categories', array('parent' => $value['id']));

            if ($subcategories->num_rows() > 0):
                $output .= $this->makeTree($value['id'], $subcategories->result_array());
            endif;
        else:
            $output .= $value['name'];
            $output .= '</li>';
        endif;
    endif;

  endforeach;

  $output .= '</ul>';
  return $output;
}

编辑 2

这是我的最终解决方案，重用数组而不是执行数据库查询：

public function makeTree($parent, $array)
{
  if (!is_array($array) OR empty($array)) return FALSE;

  $output = '<ul>';

  foreach($array as $key => $value):
    if ($value['parent'] == $parent):
        $output .= '<li>';

        if ($value['parent'] == NULL):
            $output .= $value['name'];

            $matches = array();

            foreach($array as $subkey => $subvalue):
                if ($subvalue['parent'] == $value['id']):
                    $matches[$subkey] = $subvalue;
                endif;
            endforeach;

            $output .= $this->makeTree($value['id'], $matches);

        else:
            $output .= $value['name'];
            $output .= '</li>';
        endif;
    endif;

  endforeach;

  $output .= '</ul>';

  return $output;
}
4

5 回答 5

10

虽然这似乎已回答，但请看这里。使用显示的函数，您只需一次迭代即可将平面数据转换为嵌套数据。从该嵌套数据创建 ul-list 非常容易。例如：

function nested2ul($data) {
  $result = array();

  if (sizeof($data) > 0) {
    $result[] = '<ul>';
    foreach ($data as $entry) {
      $result[] = sprintf(
        '<li>%s %s</li>',
        $entry['name'],
        nested2ul($entry['children'])
      );
    }
    $result[] = '</ul>';
  }

  return implode($result);
}

echo nested2ul(array(flat2nested( $yourFlatData ));

这种方法的好处是您不必为了找到子元素而一次又一次地重复输入数据。

于 2012-09-06T08:02:33.853 回答
2

这是我的最终解决方案，重用数组而不是执行数据库查询。如果您有更好的解决方案，请发布！

public function makeTree($parent, $array)
{
  if (!is_array($array) OR empty($array)) return FALSE;

  $output = '<ul>';

  foreach($array as $key => $value):
    if ($value['parent'] == $parent):
        $output .= '<li>';

        if ($value['parent'] == NULL):
            $output .= $value['name'];

            $matches = array();

            foreach($array as $subkey => $subvalue):
                if ($subvalue['parent'] == $value['id']):
                    $matches[$subkey] = $subvalue;
                endif;
            endforeach;

            $output .= $this->makeTree($value['id'], $matches);

        else:
            $output .= $value['name'];
            $output .= '</li>';
        endif;
    endif;

  endforeach;

  $output .= '</ul>';

  return $output;
}
于 2012-09-05T19:47:10.927 回答
1

我通常使用这样的东西，请注意

第一，这段代码使用了已弃用的mysql_*

第二你应该有一个名为 level 的数据库字段，如果为 NULL 它是主类别，如果它有一个数字，它是该数字作为 id 的类别的子类别

function getFamilies($level = 0) {
    $level++;
    $sql = "SELECT id from families WHERE level IS NULL";
    if (mysql_num_rows($result) > 0) {
        echo "<ul>";
            while($row = mysql_fetch_assoc($result)) {
                echo "<li>".$row['id'];
                    getSubFamilies($level, $row['id']);
                echo "</li>";
            }
        echo "</ul>";
    }
}

function getSubFamilies($level, $id) {
    $level++;
    $sqlSubFamilies = "SELECT id  FROM families WHERE level = ".$id."";
    $resultSubFamilies = mysql_query($sqlSubFamilies);
    if (mysql_num_rows($resultSubFamilies) > 0) {
        echo = "<ul>";
            while($rowSubFamilies = mysql_fetch_assoc($resultSubFamilies)) {
                echo "<li>".$rowSubFamilies['id'];
                    getSubFamilies($level, $rowSubFamilies['id']);
                echo "</li>";
            }
        echo "</ul>";
    }
}

getFamilies($level = 0);
于 2012-09-05T17:09:58.133 回答
0

尝试这个：

$cats = $this->db->get('categories')->result_array();

echo $this->categories->makeTree(0, $cats);

public static function makeTree($parent, $array)
{
  if (!is_array($array)) return '';

  $output = '<ul>';

  foreach($array as $key => $value):
    if ($value['parent'] == $parent):
        $output .= '<li>';

        if ($value['parent'] == NULL):
            $output .= $value['name'];
        else:

        endif;
    endif;

    $output .= '</li>';

    $output .= $this->categories->makeTree($value['parent'], $cats);

  endforeach;

  $output .= '</ul>';
  return $output;
}
于 2012-09-05T16:55:38.183 回答
-1

我认为这种使用匿名函数的方法非常简单。

//--------------------------- PRINT NESTED CATEGORIES
$cats_childs = array();

$q = $db->query("SELECT id, parent, name FROM categories");

while ($r = $db->row($q))
{
    $cats_childs[$r['parent']][$r['id']] = $r;
}

$nested2ul = function($data) use (&$nested2ul, &$cats_childs) {
    if (!empty($data)) {
        echo '<ul>';
        foreach ($data as $r) {
            echo '<li>';
            echo $r['name'];
            $flat2ul($cats_childs[$r['id']]);
            echo '</li>';
        }
        echo '</ul>';
    }
};

echo $nested2ul($cats_childs[0]);
于 2017-09-07T00:19:23.187 回答