从PHP数组为下拉选择字段创建嵌套列表 - Create nested list from PHP array for dropdown select field

我正在努力解决一个数组，我想变成一个嵌套的数组，<选择>

我需要：

<select>
<option value="1">Top1</option>
<option value="2">Top2</option>
<option value="9">Top3</option>
<option value="7"> - - Top3.1</option>
<option value="5"> - - Top3.2</option>
<option value="12">- - - - Top3.2.1</option>
<option value="6">Top4</option>
<option value="4">Top5</option>
<option value="8"> - - Top5.1</option>
<option value="3"> - - Top5.2</option>

我无法使用 optgroup，因为一切都是可选的。据我所知，您无法选择optgroup标签。

我的数组如下所示：

[44] => Array
    (
        [id] => 1
        [name] => Test
        [slug] => test
        [parent] => 0
    )
[45] => Array
    (
        [id] => 2
        [name] => Test-Sub
        [slug] => test-sub
        [parent] => 1
    )
[46] => Array
    (
        [id] => 3
        [name] => Test-Sub-Sub
        [slug] => test-sub-sub
        [parent] => 2
    )

我觉得我已经尝试了数十种变体，但我无法正确构建我的表单。

这是我的最后一次尝试：

function toDropdown($arr)
    {
        foreach ($arr as $row) {
            $cat[$row['id']] = $row['name'];
            if ($row['parent'] != 0) {
                $cat[$row['id']] = '--' . $row['name'];
            }
        }
        return $cat;
    }

但是这样，它按 ID 排序，嵌套就失去了意义。

我会尝试继续，但如果有人可以帮助我，我将不胜感激！

编辑：PHP数据

我从数据库中获取所有类别的函数：

function get_categories($parent = 'all')
{
    $this->db->select('categories.id, categories.name, categories.slug, categories.parent');
    $this->db->from('categories');
    if ($query = $this->db->get())
    {
        return $query->result_array();
    }
    return FALSE;
}

我的视图.php，我在其中输出所有数据：

$query = $this->datei_model->get_categories('all');
foreach ($query as $row)
{
    $parents[] = $row;
}
$tree = buildTree($parents);
print("<select>'n");
printTree($tree);
print("</select>");

试试这个;

function buildTree(Array $data, $parent = 0) {
    $tree = array();
    foreach ($data as $d) {
        if ($d['parent'] == $parent) {
            $children = buildTree($data, $d['id']);
            // set a trivial key
            if (!empty($children)) {
                $d['_children'] = $children;
            }
            $tree[] = $d;
        }
    }
    return $tree;
}

$rows = array(
    array ('id' => 1, 'name' => 'Test 1', 'parent' => 0),
    array ('id' => 2, 'name' => 'Test 1.1', 'parent' => 1),
    array ('id' => 3, 'name' => 'Test 1.2', 'parent' => 1),
    array ('id' => 4, 'name' => 'Test 1.2.1', 'parent' => 3),
    array ('id' => 5, 'name' => 'Test 1.2.2', 'parent' => 3),
    array ('id' => 6, 'name' => 'Test 1.2.2.1', 'parent' => 5),
    array ('id' => 7, 'name' => 'Test 2', 'parent' => 0),
    array ('id' => 8, 'name' => 'Test 2.1', 'parent' => 7),
);
$tree = buildTree($rows);
// print_r($tree);
function printTree($tree, $r = 0, $p = null) {
    foreach ($tree as $i => $t) {
        $dash = ($t['parent'] == 0) ? '' : str_repeat('-', $r) .' ';
        printf("'t<option value='%d'>%s%s</option>'n", $t['id'], $dash, $t['name']);
        if ($t['parent'] == $p) {
            // reset $r
            $r = 0;
        }
        if (isset($t['_children'])) {
            printTree($t['_children'], ++$r, $t['parent']);
        }
    }
}

print("<select>'n");
printTree($tree);
print("</select>");

输出;

<select>
    <option value='1'>Test 1</option>
    <option value='2'>- Test 1.1</option>
    <option value='3'>- Test 1.2</option>
    <option value='4'>-- Test 1.2.1</option>
    <option value='5'>-- Test 1.2.2</option>
    <option value='6'>--- Test 1.2.2.1</option>
    <option value='7'>Test 2</option>
    <option value='8'>- Test 2.1</option>
</select>

在您的情况下;

<select>
    <option value='1'>Baden-Württemberg</option>
    <option value='2'>- DMP-Verträge</option>
    <option value='50'>- Sprechstundenbedarf</option>
    <option value='52'>- Richtgrößen</option>
    <option value='53'>- Prüfungen</option>
    <option value='54'>- DMP-Verträge</option>
    <option value='55'>- Sonstige Verträge</option>
    <option value='3'>Berlin</option>
    <option value='62'>- DMP-Verträge</option>
    <option value='63'>- Prüfungen</option>
    <option value='64'>- Richtgrößen</option>
    <option value='65'>- Sonstige Verträge</option>
    <option value='66'>- Sprechstundenbedarf</option>
    <option value='4'>Brandenburg</option>
    <option value='67'>- DMP-Verträge</option>
    <option value='68'>- Prüfungen</option>
    <option value='69'>- Richtgrößen</option>
    <option value='70'>- Sonstige Verträge</option>
    <option value='71'>- Sprechstundenbedarf</option>
    <option value='5'>Bremen</option>
    <option value='72'>- DMP-Verträge</option>
    <option value='73'>- Prüfungen</option>
    <option value='74'>- Richtgrößen</option>
    <option value='75'>- Sonstige Verträge</option>
    <option value='76'>- Sprechstundenbedarf</option>
    <option value='7'>Hessen</option>
    <option value='6'>Hamburg</option>
    <option value='8'>Mecklenburg-Vorpommern</option>
    <option value='9'>Niedersachsen</option>
    <option value='10'>Nordrhein</option>
    <option value='11'>Rheinland-Pfalz</option>
    <option value='12'>Saarland</option>
    <option value='13'>Sachsen</option>
    <option value='14'>Sachsen-Anhalt</option>
    <option value='15'>Schleswig-Holstein</option>
    <option value='16'>Thüringen</option>
    <option value='17'>Westfalen-Lippe</option>
    <option value='51'>Richtgrössen</option>
    <option value='56'>Bayern</option>
    <option value='57'>- DMP-Verträge</option>
    <option value='58'>- Prüfungen</option>
    <option value='59'>- Richtgrößen</option>
    <option value='60'>- Sonstige Verträge</option>
    <option value='61'>- Sprechstundenbedarf</option>
</select>

这是

对Qeremy回答的原始代码的轻微更改

function printTree($tree, $r = 0, $p = null) {
    foreach ($tree as $i => $t) {
        $dash = ($t['parent'] == 0) ? '' : str_repeat('-', $r) .' ';
        printf("'t<option value='%d'>%s%s</option>'n", $t['id'], $dash, $t['name']);
        if (isset($t['_children'])) {
            printTree($t['_children'], $r+1, $t['parent']); 
        }
    }
}

现在，虚线名称效果很好。*对不起我的英语

在 Qeremy 的代码中，只需更改此行，代码就不会为您提供任何递增的破折号

$t['parent'] == $p

到 ->

$t['parent'] == 0