laravel implements infinite classification

$tagTree = [
    'name' => 'RootTag',
    'children' => [
        ['name' => 'L1Child1',
            'children' => [
                ['name' => 'L2Child1'],
                ['name' => 'L2Child1'],
                ['name' => 'L2Child1'],
            ]
        ],
        ['name' => 'L1Child2'],
        ['name' => 'L1Child3'],
    ]];

composer require "baum/baum:~1.1"

'Baum\Providers\BaumServiceProvider',

php artisan baum:install MODEL

php artisan migrate

class Category extends Migration {
  public function up() {
    Schema::create('categories', function(Blueprint $table) {
      $table->increments('id');

         // 这四行代码
      $table->integer('parent_id')->nullable();
      $table->integer('lft')->nullable();
      $table->integer('rgt')->nullable();
      $table->integer('depth')->nullable();

      $table->string('name', 255);

      $table->timestamps();
    });
  }}

class Category extends Baum\Node {}

class Category extends Baum\Node {
  protected $table = 'categories';

  // 'parent_id' column name
  protected $parentColumn = 'parent_id';

  // 'lft' column name
  protected $leftColumn = 'lidx';

  // 'rgt' column name
  protected $rightColumn = 'ridx';

  // 'depth' column name
  protected $depthColumn = 'nesting';

  // guard attributes from mass-assignment
  protected $guarded = array('id', 'parent_id', 'lidx', 'ridx', 'nesting');}

$root = Tag::create(['name' => 'Root']);

// 创建子标签
$child1 = $root->children()->create(['name' => 'Child1']);

$child = Tag::create(['name' => 'Child2']);
$child->makeChildOf($root);

// 批量构建树
$tagTree = [
    'name' => 'RootTag',
    'children' => [
        ['name' => 'L1Child1',
            'children' => [
                ['name' => 'L2Child1'],
                ['name' => 'L2Child1'],
                ['name' => 'L2Child1'],
            ]
        ],
        ['name' => 'L1Child2'],
        ['name' => 'L1Child3'],
    ]
];

Tag::buildTree($tagTree);