How to check which button have been submitted - php

Question

I have a form, like this:
echo '<table align=center border=1>';
echo '<form method="post">';
echo '<tr>';
echo '<th>Lista Echipamente</th>';
echo '<th>Actiune</th>';
echo '</tr>';
while($row=mysql_fetch_array($sql)){
echo '<tr>';
echo '<td><input class="search-logi" id="tip" type="text" name="tip" value="'.$row['tip'].'"></td>';
echo '<td><input type=submit name=modifica value=Modifica></td>';
echo '</tr>';
}
echo '</form>';
echo '</table>';
Because of the loop, this form will have multiple rows. For each input, will be a button.
Lets say I want to add a value in the second input, then I will submit it (also the second button, obviously). Here comes the problem, in my code I have just a button, but the user see as many as the loop goes. How can I check which button is submitted?

Answer 1

Alternatively, you could utilize <button> tags for this purpose:
echo '<form method="post">'; // form tags are outside to be valid!!!
echo '<table align=center border=1>';
echo '<tr>';
echo '<th>Lista Echipamente</th>';
echo '<th>Actiune</th>';
echo '</tr>';
while($row = mysql_fetch_assoc($sql)){
echo '<tr>';
echo '<td><input class="search-logi" type="text" name="tip['.$row['id'].']" value="'.$row['tip'].'"></td>';
echo '<td><button type="submit" name="modifica" value="'.$row['id'].'">Modifica</button</td>';
echo '</tr>';
}
echo '</table>';
echo '</form>';
Then on the processing form:
$modifica = $_POST['modifica']; // shoud return the index num
$tip = $_POST['tip'][$modifica]; // select which textbox

Answer 2

Keep some unique reference to both input and button. Let say start a counter as 1 and then make the input id as input_1 and button as button_1 and then when you click button get the counter value that is 1 for above and then get the value of input_1 as per counter 1 and submit the form. And then increase counter so that id will increase as well. I think this will help you what you need.

Answer 3

Check all your $_POST variales which are empty and which are not.
Else you could write a javascript function to set all unused fields the value to "0" or to a string and check if it is used or not e.g "unused". In your php script you can check now for the value if it is set to "0" or "unused".

Answer 4

One way is to prefix the name of the input text field with a counter or other prefix. Bases on the name of the input field you can determine which button fired.