当单击我的 Web 表单上的提交按钮时，为什么会显示输入字段的验证错误，即使这些字段有值？
When clicking the Submit button on my web form, how come the validation errors for the Input fields display, even when these fields have values?
在测试使用 HTML、CSS、Bootstrap、PHP 和 jQuery 构建的 Web 表单时，我做的第一件事是单击提交按钮。当我这样做时，文本危险错误显示在输入和文本区域字段下方，因为这些字段是空的。如果我在输入字段 "Name" 中添加一个值并再次单击提交按钮，文本危险字段将继续显示在名称字段下方。当我对电子邮件和安全检查字段尝试相同的操作时，情况也是如此。
当我在消息文本区域字段中添加值时，消息字段的文本危险错误与其他错误一起消失。消息字段需要有一个值才能使所有字段的错误消失。
我应该如何设置 jQuery 以便在将值添加到字段并单击“提交”按钮进行测试后，不再显示该特定字段的文本危险错误？
HTML 和 jQuery 代码
<div class="container">
<div class="row">
<form method="post" action="index.php" class="form-horizontal">
<div class="form-group">
<label for="name" class="col-sm-2 control-label">Name</label>
<div class="col-sm-10">
<input type="text" id="name" name="name" placeholder="Enter your name" class="form-control" value="<?php echo $name;?>">
<p class="text-danger">You need to enter a name value</p>
</div>
</div>
<div class="form-group">
<label for="email" class="col-sm-2 control-label">Email</label>
<div class="col-sm-10">
<input type="email" id="email" name="email" placeholder="your@email.com" class="form-control" value="<?php echo $email;?>">
<p class="text-danger">You need to enter a valid email</p>
</div>
</div>
<div class="form-group">
<label for="message" class="col-sm-2 control-label">Message</label>
<div class="col-sm-10">
<textarea id="message" name="message" rows="4" class="form-control"><?php echo $message;?></textarea>
<p class="text-danger">You need to enter a message</p>
</div>
</div>
<div class="form-group">
<label for="secCheck" class="col-sm-2 control-label">
<?php echo $_SESSION["a"] .'+'.$_SESSION["b"];?>
</label>
<div class="col-sm-10">
<input type="text" id="secCheck" name="secCheck" class="form-control">
<p class="text-danger">Answer the question above</p>
</div>
</div>
<div class="form-group">
<div class="col-sm-10 col-sm-offset-2">
<input type="submit" value="Send" class="btn btn-primary btn-large btn-block" id="submit" name="submit">
</div>
</div>
<div class="form-group">
<div class="col-sm-10 col-sm-offset-2">
<?php echo $result; ?>
</div>
</div
</form>
</div>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script>
$('form').on('submit',function(){
$(".text-danger").hide();
var holderValue = false;
$(this).find('input[type!="hidden"]').each(function(){
if(!$(this).val()){holderValue=true; $(this).parent().find(".text-danger").show();}
})
if(!$("#message").val()){holderValue=true; $(this).parent().find(".text-danger").show();};
if(holderValue){return false;}
// event.preventDefault();
// console.log('form submitted');
})
$("input").on("change paste keyup", function() {
if($(this).val()){
$(this).parent().find(".text-danger").hide();
}
});
$("textarea").on("change paste keyup", function() {
if($(this).val()){
$(this).parent().find(".text-danger").hide();
}
});
</script>
Bootstrap Custom Form
自定义验证需要几个关键 Bootstrap 属性和 类：
HTML
<form ... novalidate>
All <input ... required>
Remove all <p class='danger-text'>...
Replace the previous with <aside class='invalid-feedback'>
标签也已从 <div> 更改为更具语义的标签，但这不是必需的。布局也已更改——最初布局只有一个 .row，现在有几个 .form-row（不确定是否有意，但使用 [=22= 时看起来更好]).
jQuery
On each .form-control ...
$('.form-control').each(function() {...
...if the current .form-control is invalid...
if ($(this).is(':invalid')) {...
...stop the from submitting and show the invalid message...
e.preventDefault();
$(this).next('.invalid-feedback').show();...
...otherwise hide the invalid message if need be.
} else {
$(this).next('.invalid-feedback').hide();
}
演示
$('.invalid-feedback').hide();
$('#main').on('submit', function(e) {
$('.form-control').each(function() {
if ($(this).is(':invalid')) {
e.preventDefault();
$(this).next('.invalid-feedback').show();
} else {
$(this).next('.invalid-feedback').hide();
}
});
});
<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.2.1/css/bootstrap.min.css" rel="stylesheet">
<main class="container">
<form id='main' class="form-horizontal" method="post" action="index.php" novalidate>
<section class="form-row">
<fieldset class="form-group col-sm-10">
<label for="name" class="control-label">
Name
</label>
<input id="name" name="name" class="form-control" type="text" placeholder="Enter your name" required>
<aside class="invalid-feedback">
You need to enter your name.
</aside>
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10">
<label for="email" class="control-label">
Email
</label>
<input id="email" name="email" class="form-control" type="email" placeholder="your@email.com" required>
<aside class="invalid-feedback">
You need to enter your email.
</aside>
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10">
<label for="message" class="control-label">
Message
</label>
<textarea id="message" name="message" class="form-control" rows="4" required></textarea>
<aside class="invalid-feedback">
You need to enter a message.
</aside>
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10">
<label for="secCheck" class="control-label">
</label>
<input id="secCheck" name="secCheck" class="form-control" type="text" required>
<aside class="invalid-feedback">
Answer the security question above.
</aside>
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10 col-sm-offset-2">
<input id="submit" name="submit" class="btn btn-primary btn-large btn-block" type="submit" value="Send">
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10 col-sm-offset-2">
<output id='result'></output>
</fieldset>
</section>
</form>
</main>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.2.1/js/bootstrap.min.js"></script>
在测试使用 HTML、CSS、Bootstrap、PHP 和 jQuery 构建的 Web 表单时，我做的第一件事是单击提交按钮。当我这样做时，文本危险错误显示在输入和文本区域字段下方，因为这些字段是空的。如果我在输入字段 "Name" 中添加一个值并再次单击提交按钮，文本危险字段将继续显示在名称字段下方。当我对电子邮件和安全检查字段尝试相同的操作时，情况也是如此。
当我在消息文本区域字段中添加值时，消息字段的文本危险错误与其他错误一起消失。消息字段需要有一个值才能使所有字段的错误消失。
我应该如何设置 jQuery 以便在将值添加到字段并单击“提交”按钮进行测试后，不再显示该特定字段的文本危险错误？
HTML 和 jQuery 代码
<div class="container">
<div class="row">
<form method="post" action="index.php" class="form-horizontal">
<div class="form-group">
<label for="name" class="col-sm-2 control-label">Name</label>
<div class="col-sm-10">
<input type="text" id="name" name="name" placeholder="Enter your name" class="form-control" value="<?php echo $name;?>">
<p class="text-danger">You need to enter a name value</p>
</div>
</div>
<div class="form-group">
<label for="email" class="col-sm-2 control-label">Email</label>
<div class="col-sm-10">
<input type="email" id="email" name="email" placeholder="your@email.com" class="form-control" value="<?php echo $email;?>">
<p class="text-danger">You need to enter a valid email</p>
</div>
</div>
<div class="form-group">
<label for="message" class="col-sm-2 control-label">Message</label>
<div class="col-sm-10">
<textarea id="message" name="message" rows="4" class="form-control"><?php echo $message;?></textarea>
<p class="text-danger">You need to enter a message</p>
</div>
</div>
<div class="form-group">
<label for="secCheck" class="col-sm-2 control-label">
<?php echo $_SESSION["a"] .'+'.$_SESSION["b"];?>
</label>
<div class="col-sm-10">
<input type="text" id="secCheck" name="secCheck" class="form-control">
<p class="text-danger">Answer the question above</p>
</div>
</div>
<div class="form-group">
<div class="col-sm-10 col-sm-offset-2">
<input type="submit" value="Send" class="btn btn-primary btn-large btn-block" id="submit" name="submit">
</div>
</div>
<div class="form-group">
<div class="col-sm-10 col-sm-offset-2">
<?php echo $result; ?>
</div>
</div
</form>
</div>
</div>
<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.12.4/jquery.min.js"></script>
<script>
$('form').on('submit',function(){
$(".text-danger").hide();
var holderValue = false;
$(this).find('input[type!="hidden"]').each(function(){
if(!$(this).val()){holderValue=true; $(this).parent().find(".text-danger").show();}
})
if(!$("#message").val()){holderValue=true; $(this).parent().find(".text-danger").show();};
if(holderValue){return false;}
// event.preventDefault();
// console.log('form submitted');
})
$("input").on("change paste keyup", function() {
if($(this).val()){
$(this).parent().find(".text-danger").hide();
}
});
$("textarea").on("change paste keyup", function() {
if($(this).val()){
$(this).parent().find(".text-danger").hide();
}
});
</script>
Bootstrap Custom Form
自定义验证需要几个关键 Bootstrap 属性和 类：
HTML
<form ...novalidate>All
<input ...required>Remove all
<p class='danger-text'>...Replace the previous with
<aside class='invalid-feedback'>
标签也已从 <div> 更改为更具语义的标签，但这不是必需的。布局也已更改——最初布局只有一个 .row，现在有几个 .form-row（不确定是否有意，但使用 [=22= 时看起来更好]).
jQuery
On each
.form-control...
$('.form-control').each(function() {......if the current
.form-controlis invalid...
if ($(this).is(':invalid')) {......stop the from submitting and show the invalid message...
e.preventDefault();
$(this).next('.invalid-feedback').show();......otherwise hide the invalid message if need be.
} else {
$(this).next('.invalid-feedback').hide();
}
演示
$('.invalid-feedback').hide();
$('#main').on('submit', function(e) {
$('.form-control').each(function() {
if ($(this).is(':invalid')) {
e.preventDefault();
$(this).next('.invalid-feedback').show();
} else {
$(this).next('.invalid-feedback').hide();
}
});
});
<link href="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.2.1/css/bootstrap.min.css" rel="stylesheet">
<main class="container">
<form id='main' class="form-horizontal" method="post" action="index.php" novalidate>
<section class="form-row">
<fieldset class="form-group col-sm-10">
<label for="name" class="control-label">
Name
</label>
<input id="name" name="name" class="form-control" type="text" placeholder="Enter your name" required>
<aside class="invalid-feedback">
You need to enter your name.
</aside>
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10">
<label for="email" class="control-label">
Email
</label>
<input id="email" name="email" class="form-control" type="email" placeholder="your@email.com" required>
<aside class="invalid-feedback">
You need to enter your email.
</aside>
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10">
<label for="message" class="control-label">
Message
</label>
<textarea id="message" name="message" class="form-control" rows="4" required></textarea>
<aside class="invalid-feedback">
You need to enter a message.
</aside>
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10">
<label for="secCheck" class="control-label">
</label>
<input id="secCheck" name="secCheck" class="form-control" type="text" required>
<aside class="invalid-feedback">
Answer the security question above.
</aside>
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10 col-sm-offset-2">
<input id="submit" name="submit" class="btn btn-primary btn-large btn-block" type="submit" value="Send">
</fieldset>
</section>
<section class="form-row">
<fieldset class="form-group col-sm-10 col-sm-offset-2">
<output id='result'></output>
</fieldset>
</section>
</form>
</main>
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/twitter-bootstrap/4.2.1/js/bootstrap.min.js"></script>