How do I send many variables to php in html form? - php

Question

I'm trying to write a web application in which students enter their timetable. For example: First period of Monday is math, second period of Monday is English,... first period of Tuesday is history, second period of Tuesday is biology,... etc.
So I write a form like this:
<form method="post" action="timetable_handling.php">
<?php
for ($period=1;$period<=9;$period++)
{
echo "<tr>";
for ($day=1;$day<=7;$day++)
{
echo "<td><input name="the_subject_of_the_nth_$period_on_$day" type="text"></td></tr>";
//the problem is here
}
}
?>
</form>
So my question is, are there any ways to pass the many variables to another php file to handle without having to manually write its name explicitly?
Edit 1: I mean is there anyway to encode the period and day information in the name, so that when it sends to timetable_handling.php I can just loop through it to save it into sql database. Something like an array $subject[day][period].
I would be grateful if someone could help me.

Answer 1

Start with the following on your timetable data entry page:
<form method="post" action="timetable_handling.php">
<table>
<?php
for ($period=1; $period<=9; $period++)
{
echo '<tr>';
for ($day=1; $day<=7; $day++)
{
echo '<td><input name="subject_of_period_'.$period.'_on_day_'.$day.'" type="text"></td>';
//the problem is here
}
echo '</tr>';
}
?>
</table>
<input type="submit" value="Submit Form" />
</form>
Then follow up with this script on your timetable_handling.php:
<?php
for ($day=1; $day<=7; $day++)
{
for ($period=1; $period<=9; $period++ )
{
${'subject_of_period_'.$period.'_on_day_'.$day} = htmlspecialchars($_POST['subject_of_period_'.$period.'_on_day_'.$day],ENT_QUOTES);
echo '<p>Subject of Period '.$period.' on Day '.$day.' is '.${'subject_of_period_'.$period.'_on_day_'.$day}.'</p>';
}
}
?>
It's secure and it works.

Answer 2

Yes. If you format a variable name something like
for ($day=1;$day<=7;$day++)
{ ?>
<td><input name="subject['<?= $period ?>'][<?= $day ?>]" type="text"></td></tr>
//the problem is here
<?php }
PHP will turn $_POST['subject'] into a 2D array for you. (Note I make no promise this is free of syntax errors.)

Answer 3

In the form handler you can loop through all the posted fields like this:
foreach($_POST as $field => $value)
{
}
Where $field would be the input-tag name and $value it's value.
If you have other form elements you can check which ones you need with some kind of prefix, like if the fieldname starts with 'the_subject', you know it's one of the fields that were dynamically added.

Answer 4

sure, you already did part of the answer :)
first issue: you are not escaping your string properly:
Here is 1 another way
echo '<td><input name="'.$period.'_on_'.$day.'" type="text"></td></tr>';
As for handling the post here is what you can do. You might need to tweak it around to get the exact desired result. But you are talking about multidimentional array.
if (isset($_POST)){
$something=array();
foreach ($_POST as $single=>$value)
{
array_push($something, array('period_'.substr($single,0,1) => array('day_'.substr($single,-1)=>$value)));
}
}
echo '<pre>'.print_r($something,true).'</pre>';
Good Luck.