很多时候，数据都是有层级和分类的，使用laravel的Dcat框架，可以快速搭建一个结构清晰、且可以鼠标拖拽排序的后台；先上例子更直观：
这里是Dcat的模型树使用文档，戳一下；
重点注意事项有：
- 1、数据库表的parent_id字段一定要默认为0，
- 2、数据库表parent_id、order、title一定要有，不过这三个字段支持修改，可在Model中进行修改；其它字段没有要求
<?phpnamespace App\Models\Demo;use Dcat\Admin\Traits\ModelTree;
use Illuminate\Database\Eloquent\Model;class Category extends Model
{use ModelTree;protected $table = 'demo_categories';// 父级ID字段名称，默认值为 parent_idprotected $parentColumn = 'pid';// 排序字段名称，默认值为 orderprotected $orderColumn = 'sort';// 标题字段名称，默认值为 titleprotected $titleColumn = 'name';// Since v2.1.6-beta，定义depthColumn属性后，将会在数据表保存当前行的层级protected $depthColumn = 'depth';
}
tree的使用
去 Dcat 后台用代码生成工具生成 Controller 文件，生成以后直接用我下面的代码覆盖：
<?phpnamespace App\Admin\Controllers\SecondPhase;use App\Models\CancerDetectionMethods;
use App\Models\CancerDetectionSamples;
use App\Models\CancerRecommendSearch;
use App\Models\CancerSiteInfo;
use App\Models\CancerSiteMethods;
use App\Models\CancerTargets;
use App\Models\LsDicLabel;
use App\Services\CancerTargetTreesService;
use Dcat\Admin\Form;
use Dcat\Admin\Grid;
use Dcat\Admin\Http\Controllers\AdminController;
use Dcat\Admin\Layout\Column;
use Dcat\Admin\Layout\Content;
use Dcat\Admin\Layout\Row;
use Dcat\Admin\Tree;
use Dcat\Admin\Widgets\Box;
use Dcat\Admin\Widgets\Form as WidgetForm;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Support\Facades\DB;class CancerTargetsController extends AdminController
{public function index(Content $content){return $content->title('模型树')->body(function (Row $row) {$row->column(6, $this->treeView()->render());$row->column(6, function (Column $column) {$form = new WidgetForm();$form->action(admin_url('cancer-target-tree'));$form->select('parent_id', '父级')->options(CancerTargets::selectOptions());$form->text('title', '名称')->required();$column->append(Box::make('新增', $form));});});}protected function treeView(){return new Tree(new CancerTargets(), function (Tree $tree) {$tree->disableCreateButton();$tree->disableQuickCreateButton();$tree->disableEditButton();$tree->maxDepth(4);$tree->branch(function ($branch) {$payload = $branch['id'].' - '.$branch['title'];if ($branch['level'] === 4) {$url = admin_url('/cancer-site/'.$branch['id'].'/edit');$payload .= <<<HTML
<a href="$url" class="dd-nodrag">位点管理</a>
HTML;}return $payload;});});}protected function form(){return Form::make(new CancerTargets(), function (Form $form) {$form->model()->with(['methods:id, name',]);$form->display('id');$form->select('parent_id', '父级')->options(CancerTargets::selectOptions())->saving(function ($v) {return (int)$v;});$form->text('title', '名称')->required();$form->hidden('level', '等级');$form->disableViewButton();$form->footer(function ($footer) {// 去掉`重置`按钮$footer->disableReset();// 去掉`查看`checkbox$footer->disableViewCheck();// 去掉`继续编辑`checkbox$footer->disableEditingCheck();// 去掉`继续创建`checkbox$footer->disableCreatingCheck();// 设置`查看`默认选中$footer->defaultViewChecked();// 设置`继续编辑`默认选中$footer->defaultEditingChecked();// 设置`继续创建`默认选中$footer->defaultCreatingChecked();});});}}
