Keep selections in php generated form after submit (POST) - php

Question

I'm currently using php to populate a form with selections from a database. The user chooses options in a select style form and submits this, which updates a summary of the selections below the form before a second submit button is used to complete the interaction.
My issue is that every time a user uses the first submit, the selections that were there previously do not stick. They have to go through the whole form again.
Is there anyway to keep these selections present without resorting to php if statements? There are a ton of options so it would be a pain to use php for each one. Also, form is being submitted via POST.
Sample from form:
<?php
// GRAB DATA
$result = mysql_query("SELECT * FROM special2 WHERE cat = 'COLOR' ORDER BY cat")
or die(mysql_error());
echo "<div id='color'><select id='color' name='product_color'>";
while($row = mysql_fetch_array( $result )) {
$name= $row["name"];
$cat= $row["cat"];
$price= $row["price"];
echo "<option value='";echo $name;echo"'>";echo $name;echo" ($$price)</option>";}
echo "</select>";
echo "<input type='hidden' name='amount_color' value='";echo $price;echo"'></div>";
?>
I tried using this js snippet to repopulate the selections, but it does not seem to work properly...
<script type="text/javascript">document.getElementById('color').value = "<?php echo $_GET['proudct_cpu'];?>";</script>
This does not seem to work. Any suggestions other than php if statements?
Thanks!
edit: This is basically the form set up I'm using, though I've shortened it significantly because the actual implementation is quite long.
// Make a MySQL Connection
<?php mysql_connect("localhost", "kp_dbl", "mastermaster") or die(mysql_error());
mysql_select_db("kp_db") or die(mysql_error());
?>
<br />
<form action="build22.php" method="post">
<input type="hidden" name="data" value="1" />
<br />
<br />
<?php
// GRAB DATA
$result = mysql_query("SELECT * FROM special2 WHERE cat = 'color' ORDER BY cat")
or die(mysql_error());
echo "<div id='color'><select id='color' name='product_color'>";
while($row = mysql_fetch_array( $result )) {
$name= $row["name"];
$cat= $row["cat"];
$price= $row["price"];
echo "<option value='";echo $name;echo"'>";echo $name;echo" ($$price)</option>";}
echo "</select>";
echo "<input type='hidden' name='amount_color' value='";echo $price;echo"'></div>";
?>
<input type="submit" value="Update Configuration">
</form>
The selections from the form above get echoed after submission to provide the user with an update as such:
<div id="config" style="background-color:#FFF; font-size:12px; line-height:22px;">
<h1>Current Configuration:</h1>
<?php echo "<strong>Color:</strong>&nbsp&nbsp&nbsp&nbsp";echo $_POST['product_color']; ?>
</div>

Answer 1

I assume you're storing the user's selections in a separate table. If that's the case, you'll need to add some logic to determine if you should display the form values or what's already been stored.
<?php
// form was not submitted and a config id was passed to the page
if (true === empty($_POST) && true === isset($_GET['config_id']))
{
// make sure to properly sanitize the user-input!
$rs = mysql_query("select * from saved_configuration where config_id={$_GET['config_id']}"); // make sure to properly sanitize the user-input!
$_POST = mysql_fetch_array($rs,MYSQL_ASSOC); // assuming a single row for simplicity. Storing in _POST for easy display later
}
?>
<div id="config" style="background-color:#FFF; font-size:12px; line-height:22px;">
<h1>Current Configuration:</h1>
<?php echo "<strong>Color:</strong>&nbsp&nbsp&nbsp&nbsp";echo $_POST['product_color']; ?>
</div>
So after storing the user's selections in the database, you can redirect them to the page with the new config_id in the URL to load the saved values. If you're not storing the selected values in a table, you can do something similar with cookies/sessions.

Answer 2

echo the variables into the value tag of the form elements. If you post all your code I'm sure I can help you.
UPDATE
ah, so they are dropdown lists that you need to remember what was selected? Apologies, I read your post in a rush yesterday and thought it was a form with text inputs.
I just did a similar thing myself but without trying your code let me see if I can help.
Basically what you need to do is set one value in the dropdown to selected="selected"
When I had to do this I had my dropdown values in an array like so:
$options = array( "stack", "overflow", "some", "random", "words");
// then you will take your GET variable:
$key = array_search($_GET['variablename'], $options);
// so this is saying find the index in the array of the value I just told you
// then you can set the value of the dropdown to this index of the array:
$selectedoption = $options[$key];
This is where it might be confusing as my code is different so if you want to use it you will probably need to restructure a bit
I have a doSelect function to which I pass the following parameters:
// what we are passing is: name of select, size, the array of values to use and the
// value we want to use as the default selected value
doSelect("select_name", 1, $options, $selectedoption, "");
// these are the two functions I have:
// this one just processes each value in the array as a select option which is either
// the selected value or just a 'normal' select value
FUNCTION doOptions($options, $selected)
{
foreach ($options as $option)
{
if ($option == $selected)
echo ("<option title=\"$title\" id=\"$value\" selected>$option</option>\n");
else
echo ("<option title=\"$title\" id=\"$value\">$option</option>\n");
}
}
// this is the function that controls everything - it takes your parameters and calls
// the above function
FUNCTION doSelect($name, $size, $options, $selected, $extra)
{
echo("<select class=\"\" id=\"$name\" name=\"$name\" size=\"$size\" $extra>\n");
doOptions($options, $selected);
echo("</select>\n");
}
I know that's a lot of new code that's been threw at you but if you can get your select values from the db into the array then everything else should fall nicely into place.
The only thing I would add, is at the start where we call doSelect, I would put that in an if statement because you don't want to set something as selected which hasn't been set:
if (isset($_GET['variable']))
{
$key = array_search($_GET['variablename'], $options);
$selectedoption = $options[$key];
doSelect("select_name", 1, $options, $selectedoption, "");
}
else
{
doSelect("select_name", 1, $options, "", "");
}
I hope that helps!