如何在Laravel Resource类中加载嵌套关联数据以获取目标响应格式

解决方案 #

你需要对GroupUserResource中返回的group_users字段做自定义格式化，提取GroupUser关联的users属性和自身的role字段即可，以下是两种实现方案：

方案1：直接在现有资源类中处理

直接修改GroupUserResource的toArray方法，对groupUser关联集合做遍历提取目标字段：

class GroupUserResource extends JsonResource
{
    public function toArray($request)
    {
        return [
            'id'          => $this->id,
            'group_name'  => $this->name,
            'group_short' => $this->short_name,
            'description' => $this->description,
            'setting'     => $this->settings,
            'is_default'  => $this->is_default,
            'group_users' => $this->groupUser->map(function ($groupUser) {
                return [
                    'id' => $groupUser->users->id,
                    'fname' => $groupUser->users->fname,
                    'lname' => $groupUser->users->lname,
                    'email' => $groupUser->users->email,
                    'avatar' => $groupUser->users->avatar,
                    'role' => $groupUser->role,
                ];
            })
        ];
    }
}

如果需要兼容users关联为空的场景，可以用optional($groupUser->users)->xxx来避免报错。

方案2：拆分独立子资源（更推荐，可复用性高）

先创建单独的子资源类app/Http/Resources/GroupUserItemResource.php，用于格式化单条用户信息：

<?php

namespace App\Http\Resources;

use Illuminate\Http\Resources\Json\JsonResource;

class GroupUserItemResource extends JsonResource
{
    public function toArray($request)
    {
        return [
            'id' => $this->users->id,
            'fname' => $this->users->fname,
            'lname' => $this->users->lname,
            'email' => $this->users->email,
            'avatar' => $this->users->avatar,
            'role' => $this->role,
        ];
    }
}

再修改原GroupUserResource的group_users字段，调用子资源集合格式化：

class GroupUserResource extends JsonResource
{
    public function toArray($request)
    {
        return [
            'id'          => $this->id,
            'group_name'  => $this->name,
            'group_short' => $this->short_name,
            'description' => $this->description,
            'setting'     => $this->settings,
            'is_default'  => $this->is_default,
            'group_users' => GroupUserItemResource::collection($this->groupUser),
        ];
    }
}

可选优化建议 #

你的GroupUser模型中users关联为一对一关联，建议将关联名改为单数user，语义更清晰，避免误以为是多关联。

内容的提问来源于stack exchange，提问作者anurag singh