php - 如何从 PHP 中的类别字符串创建嵌套类别列表

Question

我有一个 MySQL 表“products”，其中有一列名为“category”。在此字段中，您可以找到每个产品的类别层次结构作为字符串。例如:

female / dresses / long
female / dresses / short
female / shoes  
male / shoes / sneakers / skate
...

我选择了所有不同的类别:

$result = $mysqli->query("SELECT DISTINCT category FROM products ORDER BY category");

现在，我希望能够将这些类别打印为嵌套的 HTML 列表

• 女
  • 连衣裙
    • 长
    • 短
  • 鞋子
• 男
  • 鞋子
    • 运动鞋
      • 滑冰

如有任何建议，我们将不胜感激。谢谢!

编辑:我从几个 csv 文件中获取数据，因此不需要转换类别的解决方案会很棒!

Answer 1

只需使用类别作为节点的关键字来构建您的树。例如:

$categoryLines = array(
    "female / dresses / long",
    "female / dresses / short",
    "female / shoes",
    "male / shoes / sneakers / skate"
);

function buildCategoryTree($categoryLines, $separator) {
    $catTree = array();
    foreach ($categoryLines as $catLine) {
       $path = explode($separator, $catLine);
       $node = & $catTree;
       foreach ($path as $cat) {
           $cat = trim($cat);
           if (!isset($node[$cat])) {
               $node[$cat] = array();
           }
           $node = & $node[$cat];
       }
    }
    return $catTree;
}

function displayCategoryTree($categoryTree, $indent = '') {
    foreach ($categoryTree as $node => $children) {
        echo $indent . $node . "\n";
        displayCategoryTree($children, $indent . '|- ');
    }
}

$categoryTree = buildCategoryTree($categoryLines, '/');

现在，var_export($categoryTree) 将输出:

array (
  'female' => array (
    'dresses' => array (
      'long' => array (),
      'short' => array (),
    ),
    'shoes' => array (),
  ),
  'male' => array (
    'shoes' => array (
      'sneakers' => array (
        'skate' => array (),
      ),
    ),
  ),
)

和displayCategoryTree($categoryTree) 将输出:

female
|- dresses
|- |- long
|- |- short
|- shoes
male
|- shoes
|- |- sneakers
|- |- |- skate

** 编辑 **

获取树的 HTML 表示:

function displayHtmlCategoryTree($categoryTree, $id = null, $pathSeparator = '/', $parents = '') {
    if (empty($categoryTree)) return '';

    $str = '<ul' . (!empty($id) ? ' id="'.$id.'"' : '') . '>';
    foreach ($categoryTree as $node => $children) {
        $currentPath = $parents . (empty($parents) ? '' : $pathSeparator) . $node;
        $str .= '<li title="' . $currentPath . '">' . $node . 
                displayHtmlCategoryTree($children, null, $pathSeparator, $currentPath) . 
                '</li>';
    }
    $str .= '</ul>';
    return $str;
}

echo displayHtmlCategoryTree($categoryTree, "test", ' / ');

并将输出:

<ul id="test"><li title="female">female<ul><li title="female / dresses">dresses<ul><li title="female / dresses / long">long</li><li title="female / dresses / short">short</li></ul></li><li title="female / shoes">shoes</li></ul></li><li title="male">male<ul><li title="male / shoes">shoes<ul><li title="male / shoes / sneakers">sneakers<ul><li title="male / shoes / sneakers / skate">skate</li></ul></li></ul></li></ul></li></ul>