Form problem + arrays

furious5

Can anyone help me out, I'm a bit stuck with a form I am trying to create.

Basically the form has a check box which allows a user to specify whether to display something or not. The form has two values ID & Display which I have put in to 2 seperate arrays.

I've noticed that when the form is posted back to itself, if a checkbox is not ticked for a particular value then the array has one less entry.

E.g for 5 ID's, if 3 are not checked I only get 2 results in the Display array but I get 5 results in the ID array.

Is there anyway I can overcome this problem?

LordShryku

That's just the way checkboxes work. You'd have to create an "original" array, and do a comparison that and what was passed.

furious5

Yeah I figured as much.

If we use the example of 5 values being passed in to the original array, even if I make amendments to the form and submit it and then compare the two. All I will know is the values are different.

I wouldn't be able to ascertain which values have changed, would I?

LordShryku

Sure you could. If you wanted to see which values weren't passed, do an array_diff on the two.

furious5

I suppose you could use array_diff if you have two arrays to compare.

The only way I could think to do it, it is build an array on the fly when you first loop through the db and assign the ID as the index and Display as the value to create the comparision array.

Then once the form is submitted I would then need to build 1 array from the id and display arrays passed.

My problem is how could I create 1 array from the 2 arrays passed, to match the comparision array?

devinemke

// connect to database
// assuming the "checkbox" table has 2 fields ("id" and "display") and has 5 records

$result = mysql_query ('SELECT * FROM checkbox');
while ($row = mysql_fetch_assoc ($result)) {$checkboxes[$row['id']] = $row['display'];}

echo '<form action="'. $_SERVER['PHP_SELF'] . '" method="POST">';
foreach ($checkboxes as $key => $value)
{
	echo '<input type="checkbox" name="checkboxes[]" value="' . $key . '">' . $value . '<br>' . "\n";
}
echo '<input type="submit" name="submit" value="submit"></form>';

if (isset($_POST['submit']))
{
	if (isset($_POST['checkboxes']))
	{
		echo 'you checked a total of <b>' . count($_POST['checkboxes']) . '</b> checkboxes:<br><br>';
		foreach ($_POST['checkboxes'] as $value) {echo $checkboxes[$value] . '<br>';} 
	}

else
{
	echo 'you did not check any checkboxes';
}	
}

furious5

That is spot on devin, my only question would be now. How could I then go about accessing other elements of the recordset I wanted to access for display purposes.

For instance I wanted to display a username against the checkbox, to show what you were controlling.

devinemke

well, my example pulls everything out of the table (SELECT *) so just stick it all into the array.

furious5

Yes, but the loop sequence now centres around the for each of the id and display.

What I am saying is how would you approach adding other elements from the array say for instance name?

devinemke

...how would you approach adding other elements from the array say for instance name?

then i would do a 2 dimensional array

$result = mysql_query ('SELECT * FROM checkbox'); 
while ($row = mysql_fetch_assoc ($result)) {$checkboxes[$row['id']] = $row[];} 

echo '<form action="'. $_SERVER['PHP_SELF'] . '" method="POST">'; 
foreach ($checkboxes as $key => $value) 
{ 
    echo '<input type="checkbox" name="checkboxes[]" value="' . $key . '">' . $value['display'] . '<br>' . "\n"; 
} 
echo '<input type="submit" name="submit" value="submit"></form>'; 

if (isset($_POST['submit'])) 
{ 
    if (isset($_POST['checkboxes'])) 
    { 
        echo 'you checked a total of <b>' . count($_POST['checkboxes']) . '</b> checkboxes:<br><br>'; 
        foreach ($_POST['checkboxes'] as $value)
			{
				echo '
				display: ' $checkboxes[$value]['display'] . '<br>
				name: ' $checkboxes[$value]['name'] . '<br><br>
				';
			}  

    } 

else 
{ 
    echo 'you did not check any checkboxes'; 
}     
}