Firestore安全规则-如何仅允许地图内的地图中的某些字段

rules_version = '2';
service cloud.firestore {
  match /databases/{database}/documents {
    // 限制对指定集合的访问
    match /{collection}/{document=**} {
      // 只允许认证用户访问
      allow read, write: if request.auth != null;

      // 限制字段访问
      allow read: if resource.data.location.latitude >= -90 && resource.data.location.latitude <= 90
                    && resource.data.location.longitude >= -180 && resource.data.location.longitude <= 180
                    && 'otherField' in resource.data;

      // 只允许特定字段写入
      allow create: if request.resource.data.location.latitude >= -90 && request.resource.data.location.latitude <= 90
                    && request.resource.data.location.longitude >= -180 && request.resource.data.location.longitude <= 180
                    && request.resource.data.otherField is string;

      // 更新文档时只允许特定字段修改
      allow update: if request.resource.data.diff(resource.data).affectedKeys().hasOnly(['otherField']);
    }
  }
}