Checking first radio button in dynamically generated list

Without javascript error check

[kiwibrit]

I need to generate a list of radio buttons dynamically - and ensure a button is checked. For accessibility, I do not want to use javascript, but I am content for the first button to be checked.

Dependent on a numeric variable $size, posted via a radio button on the preceding page, a list of buttons is generated from a MySQL table, which, at present, consists of 5 columns - size, drive1, drive2, drive3, and drive4. The values in the size column are numbers relating to the radio buttons on the previous page. The values in the drive columns are text - such as "electric" "gearbox" and so on.

Columns size and drive1 will always have a value. The others may not.

So far, I have come up with this code:

$query = "SELECT drive1,drive2,drive3,drive4 FROM $drivestable WHERE size = $size";
$result = mysql_query($query) or die ("Error in query: $query. " .
mysql_error());
echo '<div class=nobullets>'; // strips bullets from list
echo '<form action="nextpage.php" method="post">';
while ($row = mysql_fetch_row($result)) {
 foreach ($row as $item) {
if ($item == "") {
echo ""; // stops listing where there is no value in a drive column in $drivestable
}
else {
echo '<li>';
 echo '<p><input type="radio" name="drive" value= "' . $item . '">' . $item.'</p>';
echo '</li>';}
 }
}
echo '<p><input type="submit" name="Submit" value="Continue"> to see widget size ranges available with a' . $size .' thingamy and selected drive</p>';
 echo '</form>';
 echo '</div>';

This generates the radio buttons beautifully - but I would be grateful for adivce on how to have the first button always checked. That seems preferrable to having an error check which would cause another page to be loaded.

[NomikOS]

Respect to:
"That seems preferrable to having an error check which would cause another page to be loaded."
I am not totally agree. Some times is necessary than the user decide each time about a choice. If you give him a value by default, he will ignore it by habit.

said that see the comments: //

while ($row = mysql_fetch_row($result)) 
{  
 $i = 0; // init $i before foreach 
 foreach ($row as $item) 
 {  
  $checked = ++$i == 1? ' checked' : ''; // if first radio check it, else, not check it 
  
  ... 
  
  echo '<p><input type="radio" name="drive"'; 
  echo 'value= "'.$item.'"'.$checked.'>'; // put $checked 
  echo $item.'</p>'; 
  
  ... 

comment please...

---

[kiwibrit]

Thank you for that - I have now read about incrementing operators!

I have not seen that very neat way of writing an if / else statement before, either. I've much to learn.

However, I am still not getting the first button checked. To try and find why, I added an extra line of code - as follows:

echo '<p><input type="radio" name="drive"';
echo 'value= "'.$item.'" '.$checked.'>'; // put $checked
echo $item.'</p>';
echo $checked;

This showed the word "checked" came up where expected, after the first button.

So at the moment, I cannot see why the first button is not checked - I'd be grateful for any further thoughts.

I agree that often it is better to leave radio buttons unchecked - but in this particular case, I think it is acceptable.

[kiwibrit]

Oops. The first button check is coming up perfectly now.

I must have done a code typo somewhere in the code earlier, when I was experimenting.

Problem resolved. Thank you.

[NomikOS]

Excelent kiwibrit!

But i'm sure you will be return here sooner or later when you need than your users edit/update this data...

I will be waiting for you lol :P

---