Laravel Eloquent 模型条件性预加载：优化关系加载策略

// app/Models/User.php

class User extends Authenticatable
{
  // ... 其他属性和方法

  protected $with = [
    'domain',
    'BusinessUnits'
  ];

  public function BusinessUnits()
  {
    return $this->belongsToMany(BusinessUnit::class, 'users_business_units_pivot');
  }

  public function Domain()
  {
    return $this->belongsTo(Domain::class);
  }
}

// app/Models/User.php

class User extends Authenticatable
{
  // ... 其他属性和方法

  protected $with = [
    // 'domain',        // 移除此行
    // 'BusinessUnits'  // 移除此行
  ];

  // ...
}

// app/Models/User.php

namespace App\Models;

use Laravel\Sanctum\HasApiTokens;
use Spatie\MediaLibrary\HasMedia;
use Illuminate\Notifications\Notifiable;
use Lab404\Impersonate\Models\Impersonate;
use Spatie\MediaLibrary\InteractsWithMedia;
use Illuminate\Database\Eloquent\Casts\AsArrayObject;
use Illuminate\Database\Eloquent\Factories\HasFactory;
use Illuminate\Foundation\Auth\User as Authenticatable;

class User extends Authenticatable implements HasMedia
{
  use Traits\BaseModelTrait; // 假设存在
  use Traits\ActiveTrait;   // 假设存在

  use InteractsWithMedia;
  use Impersonate;
  use HasApiTokens;
  use Notifiable;
  use HasFactory;

  protected $hidden = [
    'password', 'remember_token',
  ];

  protected $fillable = [
    'name', 'email', 'password', 'avatar',
  ];

  protected $casts = [
    'settings' => AsArrayObject::class,
    'is_admin' => 'boolean',
  ];

  // 移除 'domain' 和 'BusinessUnits'，仅保留通用预加载
  protected $with = [
    // 'other_universal_relations_if_any',
  ];

  /**
   * The "booted" method of the model.
   *
   * @return void
   */
  protected static function boot()
  {
    parent::boot();

    // 监听 retrieved 事件，在模型从数据库检索后触发
    static::retrieved(function ($model) {
      // 如果 domain_id 不为空，则加载 domain 和 BusinessUnits 关系
      if ($model->domain_id !== null) {
        $model->load('domain', 'BusinessUnits');
      }
    });
  }

  // 关系定义
  public function BusinessUnits()
  {
    return $this->belongsToMany(BusinessUnit::class, 'users_business_units_pivot');
  }

  public function Domain()
  {
    return $this->belongsTo(Domain::class);
  }

  // 其他 Scope 定义 (保持不变)
  public function scopeAdmin($query)
  {
    return $query->where('is_admin', true);
  }

  public function scopeEmployee($query)
  {
    return $query->whereNull('domain_id');
  }

  public function scopeClient($query)
  {
    return $query->whereNotNull('domain_id');
  }
}