Несколько мыслей, Ганс.
(1) PHP не может взаимодействовать с пользователем (то есть обнаруживать события DOM, такие как нажатия кнопок или ввод текста в поле <input> и т. Д.).Это связано с тем, что после того, как DOM визуализирован и управление передано пользователю, PHP завершил работу.У него нет функциональности для взаимодействия с пользователем. Используйте javascript / jQuery.
(2) Вот простой (не проверенный) код, который может сделать то, что вы хотите:
Здесьпредложено небольшое улучшение вашего кода:
$result = $mysql->query("SELECT * FROM t_table;");
while($line = $result->fetch_array()) {
$help = $line["sNr"];
$htmlOut = "<tr>
<td>" .htmlspecialchars($line["sNr"]). "</td>
<td>" .htmlspecialchars($line["c2"]). "</td>
<td>
<form action='my.php' method='post'>
<input id="myFormID" type='text' name='$help' value='$help' onchange=".$testthis[$help] = $_POST[$help]."/>
</form>
</td>
</tr>";
$htmlOut .= "
<input id='snr_hidden' type='hidden' value='" .$line["sNr"]. "' />
<input id='phlp_hidden' type='hidden' value='" .$_POST[$help]. "' />
<!-- Note: you need jQuery library loaded before you can use jQuery js library-->
<script src="https://ajax.googleapis.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<script>
$(document).ready(function(){
$('#myFormID').blur(function(){
var tst = $(this).val();
var snr = $('#snr_hidden').val();
var pst = $('#phlp_hidden').val();
if (tst !== snr){
$('#myFormID').val(pst);
}
});
}); //END document.ready
</script>
";
echo $htmlOut;
Вот пример рабочего примера:
$(document).ready(function(){
$('#myFormID').blur(function(){
var val = $(this).val();
var tst = $('#hdnHelpVal').val();
var pst = $('#hdnPostVal').val();
if (val !== tst){
$('#inpCompare').val(pst);
}else{
$('#inpCompare').val(val);
}
});
$('#myFormID').focus(); //START with cursor in first input field
}); //END document.ready
table{border:1px solid #ccc;border-collapse:collapse;padding:5px;}
input{width:250px;}
div{color:#aaf;font-family:sans-serif;margin:25px 0;}
span{color:#89a;}
aside{display:inline;color:blue;}
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/2.2.4/jquery.min.js"></script>
<table>
<tr>
<td>
<form action='my.php' method='post'>
<input id="myFormID" type='text' value='The hidden HELP valueDELETEME' />
</form>
</td>
<td>
<input id="inpCompare" type='text' placeholder="Tab over to this field" />
</td>
</tr>
</table>
<input id="hdnHelpVal" type="hidden" value="The hidden HELP value" />
<input id="hdnPostVal" type="hidden" value="Data received via $_POST" />
<div>When you tab to the right-side field, jQuery/javascript will check the value in the left field and do something based on whether the contents == the hidden input field<br><br><span>If the left side is not (exactly) "<aside>The hidden HELP value</aside>", then the javascript code will fetch the value from input#hdnPostVal and place that data into the right side</span> </div>
Примечания к моему примеру кода:
1. Just as your code is not complete, my example is not a working example. Please just
use it to get ideas, and try some of the ideas in your project.
2. PHP is great at building an HTML page and spitting it out to the user. But once
the user has control, PHP is done. Finished. PHP has no way to interact with the user,
or to detect user events like button clicks, or changes to a drop-down, or etc.
***Use javascript/jQuery***
3. If you aren't comfortable working with javascript, I recommend learning how to use
jQuery (a javascript library) so you can come up to speed quickly and save typing.
Read this: https://stackoverflow.com/a/54757176/1447509
4. Don't use:
"<td>Something here</td>" . "<td>Summat else</td>";
when you can use:
"<td>Something here</td><td>Summat else</td>";
5. When working on tables, make sure all your HTML is placed *within* <td> elements.
Do not place <form> tags, or divs, or etc, between rows, or between <td>s - for example,
this is wrong:
<tr><td></td>In between text<td></td></tr> <=== text is between <td> elements
This is also wrong:
<tr><td>Text in table cell</td><td>Text</td></tr>
Never put anything BETWEEN rows
<tr><td>Text</td><td>Text</td></tr>
6. One way to transfer data from PHP to javascript is to write it into a hidden text
field as you are building the HTML code *(study how I did that in the above example)*.
After the DOM is written, the data just sits there, hidden, until javascript retrieves
it.
7. Note that if using the above idea, the data in that hidden input field is visible
to anyone who presses `F12` and snoops around using DevTools. A more secure way is to
save the data on the PHP side (either in MySQL or in a text file on the server) and
retrieve it on-the-fly using AJAX (which is actually pretty *easy*)