Generating HTML array variables

[canadaman]

Hi all,

I'm trying to create a page that automatically handles checkboxes and radio buttons. The problem is that the array I use for the responses doesn't necessarily have sequential answers. For example a question could have responses with IDs 5, 6, 10, and 33 depending on the order they went into the database.

What I am trying to do is read the numbers out of the database and build the variable name for verification checking. I can build the name just fine when I first construct the page but doing an if statement to test if it's been filled in is not working.

Here's the code:
Generating the initial question:
echo "<input type=checkbox value=\"$optionArray[content]\"name=\"question$question[ID][$optionArray[ID]]\">$$answerName} \n";

This creates a line like this in HTML
<input type=checkbox value="CheckBox 1" name="question5[3]">

So I'm trying to build a way of testing all the $question5[] array. But when I do I always get blanks. Doing a print_r reveals that $question5 is populated.

Code:
while ($optionArray)
{
$answerName = "question$question[ID][$optionArray[ID]]";
echo "<input type=checkbox value=\"$optionArray[content]\" ";
//TEST TO SEE IF CHECKED
if (isset($$answerName))
{
echo "name=\"question$question[ID][$optionArray[ID]]\"> {$$answerName} \n";
}
else
{
echo " CHECKED ";
echo "name=\"question$question[ID][$optionArray[ID]]\"> {$$answerName}<BR> \n";
}
$optionArray = mysql_fetch_array($optionResult);
}

When this is run the isset always returns false. I've tried printing out the constructed variable every way I can think of and I always get a blank. The name shows up fine in the HTML.

I'm concerned that this just isn't possible with variable variables.

Thanks!

[sfullman]

Think you're approaching it wrong on the arrays.

Let's say you have n number of indexes, do this:

foreach($indexes as $n=>$v){

echo "<input type=checkbox name=selectedIndexes[] value=$v ><br>";

}

This will give you an array called $selectedIndexes ranging from 0 to the quantity of options checked (php does this automatically when it receives the form collection), so you might have something like this:

$selectedIndexes[0] = '5';
$selectedIndexes[0] = '3';
$selectedIndexes[0] = '16';
$selectedIndexes[0] = '18';
$selectedIndexes[0] = '24';
HIKE!

(OK, that's a football term but hope this helps)

I didn't delve into your variable variable stuff, I think it's overly complicated for this application.

Sam Fullman

[canadaman]

Hi Sam

Thanks for your tips.

I agree that the variables are too complicated. It started out simple. Just attach the string "question" to the question number to make the HTML more readable. But when I tried to do that with the checkboxes it became this nightmare.

Do you have any suggestions on how to handle generated variable names?

Thanks!

[sfullman]

You DON'T NEED TO DO THIS, you should look at your approach.

You could do eval ('$question' . $index . '='. ' "something"; ');

if index was 1, it'd be the same as saying:

$question1 = "something";

BUT...

It's always better to use an array for this application because you can work better with an array (only need to know the name of the array and you have all the KEYS as well as the values), hence

$question[$index] = "something";
or
$question[$recordset['ID']] = "something";

I would ALMOST always use checkboxes as a value of 1, and live with a non-set value for a checkbox that wasn't checked. In other words, the NAME of the checkbox is the descriptive part, and the value just says yes/no - true/false - 1/0 -- see what I mean?

Keep thinking through the process, programming is all about elegance and doing the most with the least complexity. There's always, for any given situation, the "most elegant solution" beyond which you can't boil it down any simpler. Math majors sometimes even focus on proving that's true mathematically (I don't do that, I just use common sense :-)

Finally, if you need consulting services for like a $25.00 donation on a specific project where I review your code, I'd be happy to do that as well.

Sam Fullman
Compass Point Media

[canadaman]

Hi Sam,

I've come up with an ugly hack to get this working. I read the question array into another array and then compare it with the checkboxes coming out of the database. This gets me around the problem

Code:
$questionFinal = "question".$question[ID];
$foreachQuestion = $$questionFinal;

	foreach ($foreachQuestion as $returnedArray)
	{
		$newResults[$returnedArray]=$returnedArray;
	}
	while ($optionArray)
	{
		//Get question variable
		$questionFinal = "question".$question['ID'];
		$optionID = $optionArray["ID"];
		if ($optionID == $newResults[$optionID])
		{
			echo "<input type=checkbox value=\"$optionArray[ID]\" name=\"question$question[ID][]\" CHECKED> $optionArray[content]<BR>\n";
		}
		else
		{ 
			echo "<input type=checkbox value=\"$optionArray[ID]\" name=\"question$question[ID][]\"> $optionArray[content]<BR>\n"; //TEST
		}
		$optionArray = mysql_fetch_array($optionResult);
	}

Obviously the way I've designed this is bad. But it was a coding experiment to learn about this sort of thing so live and learn as they say.

Thanks for all your help. I really appreciate it. I'm still not 100% clear on what you were suggesting though. I was trying to use arrays and all their looping convienience but something was screwy with the way I implemented it. Hopefully I'll figure it out next time around.

Thanks again

Canadaman