如何使用面向对象技术验证PHP中的表单字段 [英] How to validate form field in PHP using Object Oriented Technique
问题描述
我创建了一个类'validate'来验证两个字段，即'firstname'和'lastname'。它不能正常工作，当字段为空时显示错误，但当我使用非空字段提交表单时，错误仍然存在。
<？php
类验证{
public $ firstName，$ lastName，$ errorFirstName =''，$ errorLastName ='';
函数__constructor（$ fName，$ lName）{
$ this-> firstName = $ fName;
$ this-> lastName = $ lName;
函数check（）{
if（$ _ SERVER [REQUEST_METHOD] ==POST）{
if（empty（ $ this-> firstName））{
$ this-> errorFirstName ='名字是必需的';
} else {
$ this-> errorFirstName ='Input is okay';
if（empty（$ this-> lastName））{
$ this-> errorLastName ='需要姓氏';
} else {
$ this-> errorLastName ='输入可以';
$ obj =新验证（$ _ POST ['firstname']，$ _POST ['lastname']） ;
$ obj-> check（）;
$ errorF = $ obj-> errorFirstName;
$ errorL = $ obj-> errorLastName;
？>
<！DOCTYPE html>
< html lang =en-USdir =ltr>
< head>
< title>主页< / title>
< meta charset =UTF-8/>
< / head>
< body>
< form method =POSTaction =<？php echo $ _SERVER [PHP_SELF]？>>
< label>名字：< / label>
< input type =textname =firstnameplaceholder =John/>
< p class =error><？php echo $ errorF;？>< / p>
< label>姓氏：< / label>
< input type =textname =lastnameplaceholder =Doe/>
< p class =error><？php echo $ errorL;？>< / p>
< input type =submit>
< / form>
< / body>
< / html>
总是会生成数据库类和验证类。 Ehh .... whaaaaay？
不要创建验证类。它从来没有工作。用于验证用户输入的最.. emm ...可持续选项包括：
$ b
- 在域实体中执行验证
- 使用值对象
通过使用实体进行验证，它非常简单。在你的情况下，你会有类 Profile ，你有方法 setFirstName（string $ name）。然后在这个方法中，你做了验证，并在错误抛出一个自定义的异常 ，像 InvalidFirstName ..或类似的东西。
使用值对象是一个有点棘手，但它可以防止代码重复。例如，您需要验证电子邮件地址。因此，您希望使用它的方式如下所示：
尝试{
$ profile = new Profile ;
$ profile-> setEmail（new EmailAddress（$ _ POST ['email']））;
} catch（InvalidArgumentException $ e）{
//验证失败
}
$ b $因此，为了获得这种行为，你应该有这样的类定义：
class EmailAddress
{
private $ email;
$ b public function __construct（int $ emailId = null，string $ email = null）
{
if（！$ this-> isValid（$ email） ）{
抛出新的InvalidArgumentException（'无效的电子邮件地址'）;
}
$ this-> email = $ email;
$ b私有函数isValid（$ email）
{
return filter_var（$ email，FILTER_VALIDATE_EMAIL）！== false;
}
public function __toString（）
{
return $ this-> email;
这种方法更具表现力，在与持久层进行交互时成为一个巨大的缺陷。
实际上，最好的选择是将这两种解决方案结合使用：
- 在实体中保留验证，对于唯一的规则
- 使用值对象来重复约束
I have created a class 'validate' to validate two fields i.e 'firstname' and 'lastname'. It is not working fine, it is showing error when field is empty but when I submit the form with non-empty fields the error is still there. How to execute this on form submission?
<?php
class validation {
public $firstName, $lastName, $errorFirstName = '', $errorLastName = '';
function __constructor($fName, $lName){
$this->firstName = $fName;
$this->lastName = $lName;
}
function check(){
if($_SERVER["REQUEST_METHOD"] == "POST"){
if(empty($this->firstName)){
$this->errorFirstName = 'First name is required';
} else {
$this->errorFirstName = 'Input is okay';
}
if(empty($this->lastName)){
$this->errorLastName = 'Last name is required';
} else {
$this->errorLastName = 'Input is okay';
}
}
}
}
$obj = new validation($_POST['firstname'], $_POST['lastname']);
$obj->check();
$errorF = $obj->errorFirstName;
$errorL = $obj->errorLastName;
?>
<!DOCTYPE html>
<html lang = "en-US" dir = "ltr">
<head>
<title>Home</title>
<meta charset = "UTF-8"/>
</head>
<body>
<form method = "POST" action="<?php echo $_SERVER["PHP_SELF"]?>">
<label>First Name: </label>
<input type = "text" name = "firstname" placeholder = "John"/>
<p class = "error"><?php echo $errorF;?></p>
<label>Last Name: </label>
<input type = "text" name = "lastname" placeholder = "Doe"/>
<p class = "error"><?php echo $errorL;?></p>
<input type="submit">
</form>
</body>
</html>
解决方案
Everyone always makes "database class" and "validation class". Ehh .... whaaaaay?
Don't make a validation class. It never works. The most .. emm ... sustainable options for validating user input are:
- perform the validation in domain entities
- use value objects
With using entities for validation, it is quite simple. In your case you would have class Profile where you have method setFirstName(string $name). Then within this method you do the validation and on error throw a custom made exception, like InvalidFirstName .. or something like that.
Using value objects is a bit trickier, but it prevents the code duplication. For example, you need to validate email address. So, the way you would want to use it would look something like:
try {
$profile = new Profile;
$profile->setEmail(new EmailAddress($_POST['email']));
} catch (InvalidArgumentException $e){
// validation failed
}
Therefore, to get this behavior, you would have the class defined kinda like this:
class EmailAddress
{
private $email;
public function __construct(int $emailId = null, string $email = null)
{
if (!$this->isValid($email)) {
throw new InvalidArgumentException('Not valid email address');
}
$this->email = $email;
}
private function isValid($email)
{
return filter_var($email, FILTER_VALIDATE_EMAIL) !== false;
}
public function __toString()
{
return $this->email;
}
}
This approach is a lot more expressive, but it tends to become a big gnarly, when interacting with persistence layer.
In practice, the best option is to use combination of these both solutions:
- keep the validation in entities, for rules, that are unique
- use value objects for often repeating constraints
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