Livewire中Call to a member function store() on null错误解决求助

问题根源 #

当未上传graduation_certificate文件时，$this->graduation_certificate的值为null，直接调用store()方法会触发该错误。

解决方法 #

在创建UserTrainee记录时，先判断文件是否存在，仅当文件存在时才执行store()方法，否则传入null。以下是两种实现方式：

方式一：提前处理文件路径（可读性更强）

修改Livewire组件的submit方法：

public function submit()
{        
    $user_uni = User::create([
        'name' => "{$this->firstName} {$this->lastName}",
        'type_id' => $this->userType,
        'email' => $this->email,
        'password' => bcrypt($this->password),
        'gender' => $this->gender,
        'mobile' => $this->mobile,
        'is_active' => 1,
    ]);
    
    // 单独处理可空的毕业证明文件
    $graduationCertPath = null;
    if ($this->graduation_certificate) {
        $graduationCertPath = $this->graduation_certificate->store('files', 'public');
    }

    UserTrainee::create([
        'user_id' => $user_uni->id,
        'region_id' => $this->region,
        'city_id' => $this->city,
        'university_id' => $this->university,
        'department_id' => $this->department,
        'major' => $this->major,
        'student_number' => $this->studentNumber,
        'gpa' => $this->gpa,
        'gpa_type' => $this->gpa_type,
        'training_date' => $this->training_date,
        'training_hours' => $this->trainingHours,
        'graduation_year' => $this->graduation_year,
        'academic_degree' => $this->academic_degree,
        'graduation_certificate' => $graduationCertPath,
        'academic_transaction' => $this->academic_transaction->store('files', 'public'),
        'cv' => $this->cv->store('files', 'public'),
        'is_graduate' => $this->traineeType,
    ]);
}

方式二：使用三元运算符（代码更简洁）

直接在create数组中处理：

public function submit()
{        
    $user_uni = User::create([
        'name' => "{$this->firstName} {$this->lastName}",
        'type_id' => $this->userType,
        'email' => $this->email,
        'password' => bcrypt($this->password),
        'gender' => $this->gender,
        'mobile' => $this->mobile,
        'is_active' => 1,
    ]);

    UserTrainee::create([
        'user_id' => $user_uni->id,
        'region_id' => $this->region,
        'city_id' => $this->city,
        'university_id' => $this->university,
        'department_id' => $this->department,
        'major' => $this->major,
        'student_number' => $this->studentNumber,
        'gpa' => $this->gpa,
        'gpa_type' => $this->gpa_type,
        'training_date' => $this->training_date,
        'training_hours' => $this->trainingHours,
        'graduation_year' => $this->graduation_year,
        'academic_degree' => $this->academic_degree,
        'graduation_certificate' => $this->graduation_certificate ? $this->graduation_certificate->store('files', 'public') : null,
        'academic_transaction' => $this->academic_transaction->store('files', 'public'),
        'cv' => $this->cv->store('files', 'public'),
        'is_graduate' => $this->traineeType,
    ]);
}

额外注意 #

确保Livewire组件中已声明对应属性：

public $graduation_certificate;

内容的提问来源于stack exchange，提问作者Bshayer