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在PHP和JavaScript中验证表单

[英]Validate form in PHP and JavaScript

我正在创建一个简单的注册表单页面(register.html):名字,姓氏,电子邮件,用户名,密码,确认密码。 我设置了它来验证JavaScript中的输入客户端,如果通过了,它将转到register.php,后者在确保安全并将其添加到数据库之前先验证后端的数据。 所有这些都很好。

但是,如果说例如后端的验证失败,就会出现问题。 我不想让客户端丢失他们输入的所有信息,而必须再次做所有事情,但是由于它已经加载了register.php,所有这些表单数据现在都位于PHP脚本中,但是位于新的页面上。 我不确定如何处理这个问题。 我可以在register.php页面上创建一个重复的表单,并在后端失败时使用PHP脚本重新填充表单。 但是,如果要执行此操作,则最好将PHP代码放入我的register.html中,然后一直运行。 但是,当我将action =“ register.html”更改为action =“”并将PHP代码放入其中时,什么也没发生。 我四处搜索并查看了isset,但是似乎也没有运行,HTML页面只是重新加载并清除了所有字段,而且我什至看不到任何回声或任何东西。

    <!DOCTYPE HTML>
<html>
    <head>
        <title>Family Beacon Registration</title>
        <style>
            .required {color: #FF0000;}
            .error {color: #FF0000;}
        </style>
        <script type="text/javascript">
            function validate()
            {
                var hasErrors = false;

                var first_name = document.forms["registration_form"]["first_name"].value;
                if(first_name == "")
                {
                    document.getElementById("first_name_error").innerHTML = "* First Name is a required field";
                    hasErrors = true;
                }
                else
                    document.getElementById("first_name_error").innerHTML = "*";

                var last_name = document.forms["registration_form"]["last_name"].value;
                if(last_name == "")
                {
                    document.getElementById("last_name_error").innerHTML = "* Last Name is a required field";
                    hasErrors = true;
                }
                else
                    document.getElementById("last_name_error").innerHTML = "*";

                var email = document.forms["registration_form"]["email"].value;
                if(email == "")
                {
                    document.getElementById("email_error").innerHTML = "* Email is a required field";
                    hasErrors = true;
                }
                else if(email.length > 40)
                {
                    document.getElementById("email_error").innerHTML = "* Email must be less than 40 characters in length.";
                    hasErrors = true;
                }
                else if(email.indexOf("@") == -1)
                {
                    document.getElementById("email_error").innerHTML = "* A valid e-mail address is required";
                    hasErrors = true;
                }
                else
                    document.getElementById("email_error").innerHTML = "*";

                var username = document.forms["registration_form"]["username"].value;
                if(username == "")
                {
                    document.getElementById("username_error").innerHTML = "* Username is a required field";
                    hasErrors = true;
                }
                else if(username.length < 3 || username.length > 20)
                {
                    document.getElementById("username_error").innerHTML = "* Username must be between 3 and 20 characters in length";
                    hasErrors = true;
                }
                else
                    document.getElementById("username_error").innerHTML = "*";

                var password = document.forms["registration_form"]["password"].value;
                if(password == "")
                {
                    document.getElementById("password_error").innerHTML = "* Password is a required field";
                    hasErrors = true;
                }
                else if(password.length < 8 || password.length > 20)
                {
                    document.getElementById("password_error").innerHTML = "* Passwords must be between 8 and 20 characters in length";
                    hasErrors = true;
                }
                else
                    document.getElementById("password_error").innerHTML = "*";

                var confirm_password = document.forms["registration_form"]["confirm_password"].value;
                if(confirm_password == "")
                {
                    document.getElementById("confirm_password_error").innerHTML = "* Confirm Password is a required field";
                    hasErrors = true;
                }
                else if(confirm_password != password)
                {
                    document.getElementById("confirm_password_error").innerHTML = "* Passwords do not match";
                    document.getElementById("password_error").innerHTML = "* Passwords do not match";
                    hasErrors = true;
                }
                else
                    document.getElementById("confirm_password_error").innerHTML = "*";

                return !hasErrors;
            }
        </script>
    </head>
    <body>  
        <h2>Family Beacon Registration</h2>
        <p><span class="required" id="required">* required field</span></p>
        <form name="registration_form" action="register.php" onsubmit="return validate();" method="post">
            First Name:<input type="text" name="first_name" id="first_name" />
            <span class="error" id="first_name_error">* </span><br><br>
            Last Name:<input type="text" name="last_name" id="last_name" />
            <span class="error" id="last_name_error">* </span><br><br>
            E-Mail:<input type="text" name="email" id="email" />
            <span class="error" id="email_error">* </span><br><br>
            Username:<input type="text" name="username" id="username" />
            <span class="error" id="username_error">* </span><br><br>
            Password:<input type="password" name="password" id="password" />
            <span class="error" id="password_error">* </span><br><br>
            Confirm Password:<input type="password" name="confirm_password" id="confirm_password" />
            <span class="error" id="confirm_password_error">* </span><br><br>
            <input type="reset" name="reset" value="Reset" />
            <input type="submit" name="submit" value="Register" />
        </form>
    </body>
</html>

首先,您的错误概念之一是将PHP代码放入名为register.html的HTML扩展文件中,该文件将永远无法使用。 第二件事是针对此问题有3种解决方案-使用AJAX调用-使用带有格式和代码的自执行PHP文件。 -使用会话(我更喜欢最少的解决方案)。

对于第一个解决方案,是将JQuery与AJAX调用结合使用的最佳方法。 为此,只需为这样的表单使用一个ID

   <form id="myForm">
    Your Form element goes here...
   </form>

然后像这样使用jquery

<script type='text/javascript'>
 $(document).ready(function(){
   $("#myForm").submit(function(){
     Your Validation code goes here.If all is ok then ...
     $.post("your_php_file_path.php",$(this)..serializeArray(),function(data){
   //here is the data is the echo you did in that php file
   //like echo "OK",you'll find data is set as string "OK"
     });
   });
});
</script>

第二个是同一页的PHP和表单,就像这样

<form action='<?php echo $_SERVER["PHP_SELF"] ?>' method='post'>
Your Form element like this
<input type='text' name='username' value='<?php echo isset($_POST['username'])?$_POST['username']:"" ?>'
</form>

并且在您的页面的最顶部使用php作为

<?php
if(count($_POST)){
//Your PHP code for validation and database insert
}
?>

这样,您可以像这样轻松地处理错误

<?php
if(count($_POST)){
//Your PHP code for validation and database insert
if(your_error_condition_occur){
   $Error = "Error Message";
  }
}
?>

在HTML部分中使用此

 <?php
  if(isset($Error)){
   echo $Error;
   }
 ?>

您可以使用会话进行页面到页面的数据传输而不会丢失它们,但是通常会话用于登录验证,所以我说不要使用它。

我可能为您工作的是:

使用jquery $(window).on("beforeunload"

所以像这样:

$(window).on("beforeunload", function() { 
    //get all the data from inputs
    //set cookie with JSON.stringify(yourData)
})

然后在身体负荷上:

如果您的Cookie存在,则JSON.parse并将其放入您的输入中

编辑:如果需要,我可以提供一些示例代码。 另外,在成功提交后,在php中,执行诸如unset($_COOKIE['yourcookie'])以便在成功提交后,您的表单不会保留其输入内容:)

了解有关AJAX的信息: https//www.w3schools.com/js/js_ajax_php.asp

AJAX的意思是: 异步 JavaScript和XML

异步状态,您将不会被重定向到该文件。 您将保留在文件中,等待服务器响应。 如果响应为否定,则可以为用户显示一些信息,如果响应为肯定的,则可以将用户重定向到另一个页面。 在响应为肯定之前,您无需将用户重定向到另一个页面,因此可以将数据保留在输入字段中。

我建议不要使用html post形式的register.php,而是建议将Ajax调用与javascript一起使用,甚至更简单地与jQuery一起使用,如果加载了它,则可以执行以下操作:

<!DOCTYPE HTML>
<html>
    <head>
        <title>Family Beacon Registration</title>
        <script src="https://code.jquery.com/jquery-3.3.1.js"></script>
        <style>
            .required {color: #FF0000;}
            .error {color: #FF0000;}
        </style>
    </head>
    <body>  
        <h2>Family Beacon Registration</h2>
        <p><span class="required" id="required">* required field</span></p>
        <div id="form">
            First Name:<input type="text" name="first_name" id="first_name" />
            <span class="error" id="first_name_error">* </span><br><br>
            Last Name:<input type="text" name="last_name" id="last_name" />
            <span class="error" id="last_name_error">* </span><br><br>
            E-Mail:<input type="text" name="email" id="email" />
            <span class="error" id="email_error">* </span><br><br>
            Username:<input type="text" name="username" id="username" />
            <span class="error" id="username_error">* </span><br><br>
            Password:<input type="password" name="password" id="password" />
            <span class="error" id="password_error">* </span><br><br>
            Confirm Password:<input type="password" name="confirm_password" id="confirm_password" />
            <span class="error" id="confirm_password_error">* </span><br><br>
            <input type="reset" name="reset" value="Reset" />
            <input id="formSubmit" type="submit" name="submit" value="Register" />
        </div>
        <script>
            $(function() {
                $("#formSubmit").click(function() {
                    var hasErrors = false,
                        first_name = document.forms["registration_form"]["first_name"].value,
                        last_name = document.forms["registration_form"]["last_name"].value,
                        email = document.forms["registration_form"]["email"].value,
                        username = document.forms["registration_form"]["username"].value,
                        password = document.forms["registration_form"]["password"].value,
                        confirm_password = document.forms["registration_form"]["confirm_password"].value;
                    if(first_name == "") {
                        document.getElementById("first_name_error").innerHTML = "* First Name is a required field";
                        hasErrors = true;
                    } else {
                        document.getElementById("first_name_error").innerHTML = "*";
                    }
                    if(last_name == "") {
                        document.getElementById("last_name_error").innerHTML = "* Last Name is a required field";
                        hasErrors = true;
                    } else {
                        document.getElementById("last_name_error").innerHTML = "*";
                    }
                    if(email == "") {
                        document.getElementById("email_error").innerHTML = "* Email is a required field";
                        hasErrors = true;
                    } else if(email.length > 40) {
                        document.getElementById("email_error").innerHTML = "* Email must be less than 40 characters in length.";
                        hasErrors = true;
                    } else if(email.indexOf("@") == -1) {
                        document.getElementById("email_error").innerHTML = "* A valid e-mail address is required";
                        hasErrors = true;
                    } else {
                        document.getElementById("email_error").innerHTML = "*";
                    }
                    if(username == "") {
                        document.getElementById("username_error").innerHTML = "* Username is a required field";
                        hasErrors = true;
                    } else if(username.length < 3 || username.length > 20) {
                        document.getElementById("username_error").innerHTML = "* Username must be between 3 and 20 characters in length";
                        hasErrors = true;
                    } else {
                        document.getElementById("username_error").innerHTML = "*";
                    }
                    if(password == "") {
                        document.getElementById("password_error").innerHTML = "* Password is a required field";
                        hasErrors = true;
                    } else if(password.length < 8 || password.length > 20) {
                        document.getElementById("password_error").innerHTML = "* Passwords must be between 8 and 20 characters in length";
                        hasErrors = true;
                    } else {
                        document.getElementById("password_error").innerHTML = "*";
                    }
                    if(confirm_password == "") {
                        document.getElementById("confirm_password_error").innerHTML = "* Confirm Password is a required field";
                        hasErrors = true;
                    } else if(confirm_password != password) {
                        document.getElementById("confirm_password_error").innerHTML = "* Passwords do not match";
                        document.getElementById("password_error").innerHTML = "* Passwords do not match";
                        hasErrors = true;
                    } else {
                        document.getElementById("confirm_password_error").innerHTML = "*";
                    }

                    if(!hasErrors) {
                        $.post( "register.php", {
                            first_name: first_name,
                            last_name: last_name,
                            email: email,
                            username: username,
                            password: password,
                            confirm_password: confirm_password
                        })
                        .done(function(data) {
                            // Data is the PHP echoed output.
                            alert(data);
                        })
                        .fail(function() {
                            alert( "error" );
                        });
                    }
                });
            });
        </script>
    </body>
</html>

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