根据回答的问题，我如何以要求的形式提出一些问题

Question

根据填写的问题，我希望输入所需的一半，另一半留空。

基本上我有一个这样的表格：

//first set
<p>Source: <input type="text" name="source" class="task_input"></p>
<p>Date Earned: <input type="text" name="date_earned" class="task_input"></p>
<p>Amount Earned: <input type="text" name="earned" class="task_input"></p>

//second set
<p>Recipient: <input type="text" name="recipient" class="task_input"></p>
<p>Date Given: <input type="text" name="date_given" class="task_input"></p>
<p>Amount Given: <input type="text" name="given" class="task_input"></p>

我希望用户填写第一组或第二组，并填写用户选择的所有3个。我为错误设置了一个if语句，如下所示：

if (isset($_POST['submit'])) {
if ((empty($_POST['source'])||($_POST['date_earned'])||($_POST['earned']))&&(empty($_POST['recipient'])&&($_POST['date_given'])&&($_POST['given']))){
$errors = "Looks like you left something out...";
}elseif ((empty($_POST['recipient'])||($_POST['date_given'])||($_POST['given']))&&(empty($_POST['source'])&&($_POST['date_earned'])&&($_POST['earned']))){
$errors = "Looks like you left something out...";
}else{
//submit

问题是，如果任何东西都是空的，即使我试图将其拆分，它也会发送一条错误消息。我的另一个选择是删除所有错误消息，但这意味着三个必需输入中的任何一个或全部都可以为空，没有错误消息。

我应该如何写这个if语句，这样我才能得到我需要的结果？

Answer 1

您可以使用一些相当简单的javascript，通过确保在任何单个输入元素中识别出输入后立即禁用替代输入，诱使用户完成一个或另一个部分。这不会否定对验证服务器端的需求，因为通过其他措施(例如：curl等(禁用javascript或处理表单很容易，但作为初始接口可能很有用。

您可以在下面的片段中看到效果。

const d=document;
const bttn=d.querySelector('input[type="submit"]');
d.addEventListener('input',e=>{
// fetch the parent node and it's data-id value
let section=e.target.closest('section')
let id=Number( section.dataset.id );

// make sure button is disabled
bttn.disabled=true;

// use the data-id value to find the other section using 1 - x logic
// and disable all inputs within that other section. The user can now
// only complete entries in one or other section at a time.
let alt=d.querySelectorAll(`section[ data-id="${1-id}" ] input`)
alt.forEach(input=>{
input.disabled=true;
});



// find inputs within current section and convert nodelist to an array
let col=[ ...section.querySelectorAll('input') ];
// find the initial number of input elements in the array.
let len=col.length;
// filter the array to remove empty (&/or other criteria) inputs.
col=col.filter( input=>input.value!='' );

// If all inputs are cleared, the other section should be re-enabled.    
if( col.length==0 )alt.forEach(input=>{
input.disabled=false;
});

// enable the button if all fields are populated.
if( col.length==len ){
bttn.disabled=false;
}
})

section,label{display:block; box-sizing:border-box; padding:0.25rem}
section{margin:1rem 0}
label{ width:50%; margin:0.1rem 0 }
label input{float:right}

<form method='post'>
<section data-id=0>
<label>Source: <input type="text" name="source" class="task_input" /></label>
<label>Date Earned: <input type="text" name="date_earned" class="task_input" /></label>
<label>Amount Earned: <input type="text" name="earned" class="task_input" /></label>
</section>

<section data-id=1>
<label>Recipient: <input type="text" name="recipient" class="task_input" /></label>
<label>Date Given: <input type="text" name="date_given" class="task_input" /></label>
<label>Amount Given: <input type="text" name="given" class="task_input" /></label>
</section>
<input type='submit' disabled />

</form>

为了处理表单数据，而不是多个isset或empty调用，因为逻辑可能会变得过于混乱，您可以检查密钥是否提交了

<?php
if( $_SERVER['REQUEST_METHOD']=='POST' ){

$errors=array();

$sets=array(
array('source','date_earned','earned'),
array('recipient','date_given','given')
);

# filter the POST array to remove empty items.
$_POST=array_filter( $_POST );

# if no elements are populated abandon processing.
if( empty( $_POST ) )echo '<h3>Empty POST - one or other set of inputs must be completed</h3>';
else{

# arbitary but take the first key in the POST array. If other keys are not in the same set there is a problem.
$keys=array_keys( $_POST );
$key=$keys[0];
$set=in_array( $key, $sets[0] ) ? $sets[0] : $sets[1];


# loop through the POST array, if any field is not in the same set as the first array key, it is an error.
foreach( $_POST as $field => $value ){
if( !in_array( $field, $set ) )$errors[ $field ]='Incorrect set';
if( empty( $value ) && !in_array( $field, $set ) )$errors[ $field ]='Incorrect set &amp; also empty';
}

# make sure that all fields from selected set are not empty, otherwise it is an error.
foreach( $set as $field ){
if( empty( $_POST[ $field ] ) )$errors[ $field ]='Cannot be empty';
}

if( !empty( $errors ) ){
#handle errors in some manner.
foreach( $errors as $field => $errmsg )printf('<div>%s: %s</div>', $field, $errmsg );
}else{
#celebrate
echo '<h3>That is acceptable</h3>';
}
}
}
?>