需求

1.点击分类的修改

2.实现这里的上下级关系

准备素材

1.安装laravel
2.安装laravle-admin
3.分类数据库

提供素材

这里就只提供数据库的素材了，至于laravel跟laravel-admin的素材自己直接下载即可

模型文件

存放位置app\Models\GoodsCategory.php
然后放置下面的内容

<?php

namespace App\Models;

use Encore\Admin\Traits\AdminBuilder;
use Encore\Admin\Traits\ModelTree;
use Illuminate\Database\Eloquent\Model;

/**
 * 商品分类
 */
class GoodsCategory extends Model
{
    use ModelTree, AdminBuilder;

    protected  $fillable = ['name', 'category_image'];

    protected $appends = ['levels'];

    public function __construct(array $attributes = [])
    {
        parent::__construct($attributes);

        $this->setParentColumn('parent_id');
        $this->setOrderColumn('sort');
        $this->setTitleColumn('name');
    }

    public function parent()
    {
        //反向关联
        return $this->belongsTo(GoodsCategory::class);
    }

    public function children() {
        //一对多
        return $this->hasMany(GoodsCategory::class, 'parent_id');
    }

    //定义一个访问器，获取所有祖先类目的ID值
    public function getPossessIdsAttribute()
    {
        //array_filter 将数组中的空值移除
        return array_filter(explode('-', trim($this->possess, '-')));
    }

    //定义一个访问器，获取祖先类目并按层级排序
    public function getAncestorsAttribute()
    {
        return GoodsCategory::query()
            ->whereIn('id', $this->possess_ids)
            //按层级排序
            ->orderBy('level')->get();
    }

    //定义一个访问器，获取以 - 为分隔的所有祖先类目的名称以及当前类目的名称
    public function getFullNameAttribute()
    {
        return $this->ancestors //获取所有祖先类
            ->pluck('name') //获取祖先类目的name 字段为一个数组
            ->push($this->name)//获取当前类目的 name 字段加到数组的末尾
            ->implode(' - '); //用 - 符合将数组的值组成一个字符串
    }

    public function getLevelsAttribute($value) {
        $data = [
            '0' => '根目录',
            '1' => '二级',
            '2' => '三级',
        ];
        // return (is_null($value)) ? $data : $data[$value];
        return (is_null($this->attributes['level'])) ? $data : $data[$this->attributes['level']];
    }

    /**
     * 测试方法
     * @return [type] [description]
     */
    public function test()
    {
        $category = GoodsCategory::where('id', 105)->first();
        $data = $category->ancestors->toArray();
        return $data;
    }
}

数据库迁移文件

把这个份文件放database\migrations
执行创建迁移文件

php artisan make:migration create_goods_category_table --create=GoodsCategory

在执行迁移文件

php artisan migrate

<?php

use Illuminate\Support\Facades\Schema;
use Illuminate\Database\Schema\Blueprint;
use Illuminate\Database\Migrations\Migration;

class CreateGoodsCategoriesTable extends Migration
{
    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('goods_categories', function (Blueprint $table) {
            $table->increments('id')->comment('商品类别主键id');
            $table->string('name')->comment('类别名称');
            $table->integer('parent_id')->default(0)->comment('父级类别id');
            $table->string('image')->nullable()->comment('分类图片');
            $table->integer('level')->default(0)->comment('分类等级');
            $table->integer('sort')->default(0)->comment('分类排序');
            $table->timestamps();
        });
    }

    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::dropIfExists('goods_categories');
    }
}

数据库填充文件

<?php
use App\Models\GoodsCategory;
use Illuminate\Database\Seeder;

class GoodsCategoryTableSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        $categories = [
            [
                'name'     => '手机配件',
                'sort'     => '0',
                'children' => [
                    [
                        'name'     => '手机壳',
                        'sort'     => '0',
                        'children' => [
                            [
                                'name' => '华为V10手机',
                                'sort'     => '0',
                            ],
                            [
                                'name' => '小米',
                                'sort'     => '1',
                            ],
                        ],
                    ],
                    [
                        'name'     => '数据线',
                        'sort'     => '4',
                        'children' => [
                            [
                                'name' => '苹果数据线',
                                'sort'     => '0',
                            ],
                            [
                                'name' => '安卓数据线',
                                'sort'     => '1',
                            ],
                        ],
                    ],
                    [
                        'name'     => '耳机',
                        'sort'     => '0',
                        'children' => [
                            [
                                'name' => '有线耳机',
                                'sort'     => '1',
                            ],
                            [
                                'name' => '蓝牙耳机',
                                'sort'     => '0',
                            ],
                        ],
                    ],
                ],
            ],
            [
                'name'     => '六星果园',
                'sort'     => '0',
                'children' => [
                    [
                        'name'     => '国产水果',
                        'sort'     => '0',
                        'children' => [
                            [
                                'name' => '苹果',
                                'sort'     => '0',
                            ],
                            [
                                'name' => '梨',
                                'sort'     => '1',
                            ],
                        ],
                    ],
                ]
            ]
        ];
        foreach ($categories as $data) {
            $this->createCategory($data);
        }

    }
    public function createCategory($data, $parent = null)
    {
        // 创建一个分类
        $category = new GoodsCategory([
            'name' => $data['name'],
            'sort' => $data['sort'],
        ]);
        // 如果有父级参数，代表有父类目
        if (!is_null($parent)) {
            // 将模型实例与给定的父实例关联。
            $category->parent()->associate($parent);
        }
        // 保存到数据库
        $category->save();
        // 如果有children字段并且 children字段是一个数组
        if (isset($data['children']) && is_array($data['children'])) {
            foreach ($data['children'] as $child) {
                $this->createCategory($child, $category);
            }
        }
    }
}

文件放在database\seeds\GoodsCategoryTableSeeder.php

这里还需要一个观察者
app\Observers\GoodsCategoryObserver.php

php artisan make:observer GoodsCategoryObserver --model=GoodsCategory

然后里边放置下面内容

<?php

namespace App\Observers;

use Log;
use App\Models\GoodsCategory;

class GoodsCategoryObserver
{
    public function creating(GoodsCategory $goodsCategory) {
        //如果创建的是一个根类目
        if (is_null($goodsCategory->parent_id)) {
            //讲层级设置为0
            $goodsCategory->level = 0;
            //将path 设为 -
            $goodsCategory->possess = '-';
        }else {
            //将层级设为父类目层级 + 1
            $goodsCategory->level = $goodsCategory->parent->level +1;
            Log::info($goodsCategory->level);
            // 将path 设为父级目的的PATH 追加父级的id 并最后 跟上一个  -  分隔符
            $goodsCategory->possess = $goodsCategory->parent->possess.$goodsCategory->parent_id.'-';
        }
    }
    /**
     * Handle the goods category "created" event.
     *
     * @param  \App\GoodsCategory  $goodsCategory
     * @return void
     */
    public function created(GoodsCategory $goodsCategory)
    {

    }

    /**
     * Handle the goods category "updated" event.
     *
     * @param  \App\GoodsCategory  $goodsCategory
     * @return void
     */
    public function updated(GoodsCategory $goodsCategory)
    {
        //
    }

    /**
     * Handle the goods category "deleted" event.
     *
     * @param  \App\GoodsCategory  $goodsCategory
     * @return void
     */
    public function deleted(GoodsCategory $goodsCategory)
    {
        //
    }

    /**
     * Handle the goods category "restored" event.
     *
     * @param  \App\GoodsCategory  $goodsCategory
     * @return void
     */
    public function restored(GoodsCategory $goodsCategory)
    {
        //
    }

    /**
     * Handle the goods category "force deleted" event.
     *
     * @param  \App\GoodsCategory  $goodsCategory
     * @return void
     */
    public function forceDeleted(GoodsCategory $goodsCategory)
    {
        //
    }
}

然后需要注册一个服务
app\Providers\ModelObserverProvider.php

php artisan make:provider ModelObserverProvider

里边添加这些代码

<?php

namespace App\Providers;

use App\Observers\GoodsCategoryObserver;
use App\Models\GoodsCategory;
use Illuminate\Support\ServiceProvider;

class ModelObserverProvider extends ServiceProvider
{
    /**
     * Register services.
     *
     * @return void
     */
    public function register()
    {
        //
    }

    /**
     * Bootstrap services.
     *
     * @return void
     */
    public function boot()
    {
        GoodsCategory::observe(GoodsCategoryObserver::class);
    }
}

然后打开config\app.php，进行注册服务

准备操作后台显示问题

注意模型里边添加的这些代码

然后返回到控制器

然后效果即可

本作品采用《CC 协议》，转载必须注明作者和本文链接