Making a selection on a drop-down menu from another page

[sampharo]

After sorting out a registration form that contains a drop-down menu of courses (thanks again to Krik's help), I wanted now to have visitors be able to scan through the courses and their details laid out in an html table on another page, and then let the visitor click a button (lined up next to the course desired), and have the registration form load with that option selected in the drop-down menu.

What php script would do that, or is it better to use javascript?

[ixalmida]

I didn't see your previous post, so I'm not familiar with your code, but normally I'd have the following type of button for each course:

<input type="button" name="course_name" value="Add Course"
  onclick="window.location='add_course.php?course_id=1234'" />

...where 1234 is the course number.

I prefer to use intermediate processing pages because it prevents any possibility of re-posting data, so I'd a page "add_course.php". This page would have the sole function of adding a course to the user's registration list. Again, I'm not sure where that list would reside for you, but I'd normally put it into a pre-registration table keyed to the user's ID. So:

$user_id = $_SESSION['user_id'];
$course_id = $_GET['course_id'];
// In our URL, the course_id is 1234

// Make sure you validate your variables before running the query!

mysql_query("INSERT INTO PreRegistration (user_id, course_id) VALUES
  ($user_id, $course_id)");
// This adds course_id 1234 to the PreRegistration table

// Now go to the user's registration page...
header("location: registration.php");

And in your registration page:

$user_id = $_SESSION['user_id'];

// Get user's pre-registration list...
$result = mysql_query("SELECT course_id, course_name FROM PreRegistration
  WHERE user_id = $user_id");

// Output course list below...
while($row = mysql_fetch_assoc($result))
{
  // Output the courses/form elements here!
}

[sampharo]

Hi ixalmida,

Well my last post was just resolved, it was titled "select menu".

I wouldn't go this deep since I am using a simple array and a drop-down menu, so there won't be much manipulation possible. Also I am very limited in my coding and programming ability and this looks like it is delving into mysql.

Would there be a simpler solution? Could this code:

<input type="button" name="course_name" value="Add Course"
  onclick="window.location='add_course.php?course_id=1234'" />

be made to deal directly with the registration form already made with some form of modification? Here is the registration form so you can have an idea of what we're dealing with (dots in the arrays are to truncate a long list of entries):

<div class="container"> <br />            	
  <!-- The contact form starts from here-->
    <?php

$coursearray = array(
'Mngmnt & Leadership: Modern Trends in Leadership and Supervision Skills',
'Mngmnt & Leadership: Modern Trends of Hospitals Management',
.
.
.
'Acc & Finance: Reading , interpreting and analyzing financial statements',
'Acc & Finance: Management of Bad Debts'
); // you enter the options here for the courses

$datearray = array(
	  '06-10 September 2010',
      '20-24 September 2010',
.
.
.
      '25-29 July 2011'
); // you enter the options here for the dates

			 $error    = ''; // error message
             $name     = ''; // sender's name
             $email    = ''; // sender's email address
             $subject  = 'Course Registration Form'; // subject
             $message  = ''; // the message itself
           	 $spamcheck = ''; // Spam check

        if(isset($_POST['send']))
        {
             $name     = $_POST['name'];
             $email    = $_POST['email'];
             $subject  = $_POST['subject'];
             $message  = $_POST['message'];
           	 $spamcheck = $_POST['spamcheck'];

/* first we need to require our MathGuard class */
require ("ClassMathGuard.php");
/* this condition checks the user input. Don't change the condition, just the body within the curly braces */
if (MathGuard :: checkResult($_REQUEST['mathguard_answer'], $_REQUEST['mathguard_code'])) {
	echo (""); //insert your code that will be executed when user enters the correct answer
} else 			{
                $error = '<div class="errormsg">The Mathguard anti-spam number you entered is wrong. Please enter the correct answer.</div>';
                }

			if(trim($name) == '')
            {
                $error = '<div class="errormsg">Please enter your name!</div>';
            }
        	else if(trim($email) == '')
            {
                $error = '<div class="errormsg">Please enter your email address!</div>';
            }
            else if(!isEmail($email))
            {
                $error = '<div class="errormsg">You have entered an invalid e-mail address. Please, try again, with a proper email address that contains the "@" sign.</div>';
            }
        	else if(trim($subject) == '')
            {
                $error = '<div class="errormsg">Please enter a subject!</div>';
            }

          	else if($error == '')
            {
            	if(get_magic_quotes_gpc())
                {
                    $message = stripslashes($message);
                }

                // the email will be sent here
                // make sure to change this to be your e-mail
                $to      = "[e-mail], [e-mail]";

                // the email subject
                // '[Contact Form] :' will appear automatically in the subject.
                // You can change it as you want

                $subject = '[Emirates Enterprise] : ' . $subject;

                // the mail message ( add any additional information if you want )
                $msg     = "From : $name \r\ne-Mail : $email \r\nSubject : $subject \r\n\n Course chosen: $coursearray[$course] \r\n\n Date: $datearray[$date]\r\n\n" . "Message : \r\n$message";

                mail($to, $subject, $msg, "From: $email\r\nReply-To: $email\r\nReturn-Path: $email\r\n");

				// autoresponder subject
				$subject2 = 'Course Registration Confirmation: Thank you for your registration';

				// autoresponder message
				$msg2	= "Dear $name \r\n\nThank you for registering to attend our '$coursearray[$course]' course, booked to be attended between $datearray[$date].\r\n\nPlease wait for contact from us to process your registration\r\n";

				mail($email, $subject2, $msg2, "From: $to\r\nReply-To: $to\r\nReturn-Path: $to\r\n");			
					?>
  <!-- Message sent! (change the text below as you wish)-->
  <div style="text-align:center;">
    <h1>Dear <?php echo $name;?>. Thank You For Registering</h1>
    <p><font size="3">Your Course Registration has been Successfully submitted. You will receive an email confirming the course details.</font></p>
    <p>&nbsp;</p>
    <p><font size="3">Please, contact us if you need anything further through the <a href="./contact.html"Contact Us</a> page, or call directly one of the phone numbers listed there.</font></p> 

  </div>
  <!--End Message Sent-->
  <?php
                }
            }

        if(!isset($_POST['send']) || $error != '')
        {
        ?>
  <h1><center>Registration Form:</center></h1>
  <p><font size="3"><font color="#FF0000">IMPORTANT:</font> Please choose the <strong>preferred date</strong> of the course you wish to attend from the date drop down menu, and confirm the course you wish to attend. Afterwards, enter your name, company, phone number (with country code) and email address in the forms below.</font></p> 
  <p><font size="3">Add any specific details or instructions if you wish in the message field and click submit to receive an email confirming your registration, and notifying one of our consultants to contact you.</font></p>
  <p>(Fields marked with a <span class="required">*</span> are compulsory)</p>
  <!--Error Message-->
  <?php 

echo $error;?>
  <form  method="post" name="regFrm" id="regFrm" action="">
    <label><span class="required">*</span> Course:  </label>
    <select name='course' id='course'>
<?php
foreach ($coursearray as $key => $value ) {

if(isset($_POST['course']) && $key == $_POST['course']) {
    echo '<option value="' . $key . '" selected>  ' . $value . '</option>';
}
else {
    echo '<option value="' . $key . '">  ' . $value . '</option>';
}
}
?>
    </select><br />
    <label><span class="required">*</span> Date:</label>
    <select name='date' id='Listbox1'>
<?php
foreach ($datearray as $key => $value ) {

if(isset($_POST['date']) && $key == $_POST['date']) {
    echo '<option value="' . $key . '" selected>  ' . $value . '</option>';
}
else {
    echo '<option value="' . $key . '">  ' . $value . '</option>';
}
}
?>
    </select><br /> 
    <label><span class="required">*</span> Full Name:</label>
    <input name="name" type="text" class="box" id="name" size="30" value="<?php echo $name;?>" /><br />
    <label><span class="required">*</span> Email: </label>
    <input name="email" type="text" class="box" id="email" size="30" value="<?php echo $email;?>" /><br />
    <label><span class="required">*</span> Subject: </label>
    <input name="subject" type="text" class="box" id="subject" size="30" value="<?php echo $subject;?>" /><br />
    <label>Message: </label>
    <textarea name="message" cols="40" rows="3"  id="message"><?php echo $message;?>
</textarea><br />
	<label><span class="required">* Security Question</span></label><? require_once ("ClassMathGuard.php"); MathGuard::insertQuestion(); ?>
    <br />
    <br />
    <!-- Submit Button-->
    <input name="send" type="submit" class="button" id="send" value="" />
  </form>
  <!-- E-mail verification. Do not edit -->
  <?php
            }

        function isEmail($email)
        {
            return(preg_match("/^[-_.[:alnum:]]+@((([[:alnum:]]|[[:alnum:]][[:alnum:]-]*[[:alnum:]])\.)+(ad|ae|aero|af|ag|ai|al|am|an|ao|aq|ar|arpa|as|at|au|aw|az|ba|bb|bd|be|bf|bg|bh|bi|biz|bj|bm|bn|bo|br|bs|bt|bv|bw|by|bz|ca|cc|cd|cf|cg|ch|ci|ck|cl|cm|cn|co|com|coop|cr|cs|cu|cv|cx|cy|cz|de|dj|dk|dm|do|dz|ec|edu|ee|eg|eh|er|es|et|eu|fi|fj|fk|fm|fo|fr|ga|gb|gd|ge|gf|gh|gi|gl|gm|gn|gov|gp|gq|gr|gs|gt|gu|gw|gy|hk|hm|hn|hr|ht|hu|id|ie|il|in|info|int|io|iq|ir|is|it|jm|jo|jp|ke|kg|kh|ki|km|kn|kp|kr|kw|ky|kz|la|lb|lc|li|lk|lr|ls|lt|lu|lv|ly|ma|mc|md|mg|mh|mil|mk|ml|mm|mn|mo|mp|mq|mr|ms|mt|mu|museum|mv|mw|mx|my|mz|na|name|nc|ne|net|nf|ng|ni|nl|no|np|nr|nt|nu|nz|om|org|pa|pe|pf|pg|ph|pk|pl|pm|pn|pr|pro|ps|pt|pw|py|qa|re|ro|ru|rw|sa|sb|sc|sd|se|sg|sh|si|sj|sk|sl|sm|sn|so|sr|st|su|sv|sy|sz|tc|td|tf|tg|th|tj|tk|tm|tn|to|tp|tr|tt|tv|tw|tz|ua|ug|uk|um|us|uy|uz|va|vc|ve|vg|vi|vn|vu|wf|ws|ye|yt|yu|za|zm|zw)$|(([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5])\.){3}([0-9][0-9]?|[0-1][0-9][0-9]|[2][0-4][0-9]|[2][5][0-5]))$/i"
                    ,$email));
        }
        ?>

  <!-- END CONTACT FORM -->
			</div>

[ixalmida]

Short answer - yes. Put whatever variables you want in the URL...course_id, course_name, etc. Just remember to urlencode() any text and then url_decode(). If you aren't using a database, there isn't much danger of sql injection, but if you have any security on your site (logins, sessions, cookies, whatever), bear in mind that echoing GET variables directly to the web page is not secure. Read up on PHP session security.

URL: mysite.com/mypage.php?course_id=1234&course_name=Economics

echo $_GET['course_id'];
// displays:  1234

echo $_GET['course_name'];
// displays:  Economics

[sampharo]

Hi ixalmida,

Thanks for this. Just a couple of questions:

1- I don't have any sessions or logins on my site, only information and two form to emails. However it would still be smart for me to at least encode the url and decode it like you said. How exactly though do I do that?

2- Does the course_id refer to the key or value of the specific course in the array? I don't see how "course_name" and "course_id" can be defined towards the array, so was I supposed to change that to "$course"?

3- Where do I place the $_GET commands?

[sampharo]

The echo order was only displaying the value I gave, it didn't communicate with the array.

From reading around and pure beginner's luck, I managed to put the following code together that actually worked. 🙂
However, please tell me though if it has any security "hazards" or possible errors in this, in case there is something I am missing.

I used the submit button format:

<input type="button" name="course_name" value="Register"
  onclick="window.location='register.php?course=1234'" />

And I changed this code in register.php which was responsible for maintaining the selection in case the page fails validation:

foreach ($coursearray as $key => $value ) {

if(isset($_POST['course']) && $key == $_POST['course']) {
    echo '<option value="' . $key . '" selected>  ' . $value . '</option>';
}
else {
    echo '<option value="' . $key . '">  ' . $value . '</option>';
}
}
?>

into this:

foreach ($coursearray as $key => $value ) {

if(isset($_GET['course']) && $key == $_GET['course']) {	
	echo '<option value="' . $key . '" selected>  ' . $value . '</option>';
}
else if(isset($_POST['course']) && $key == $_POST['course']) {
    echo '<option value="' . $key . '" selected>  ' . $value . '</option>';
}
else {
    echo '<option value="' . $key . '">  ' . $value . '</option>';
}
}
?>

I figured that if the result of the $_post was to select a certain value, then I can just copy pasted that code and put GET as an earlier option, hence it will apply the GET choice if there is one, and if there isn't one, it will stick to whatever selection the registration form comes to as a default.

Is that correct coding?

And also please explain the "encodeurl()" that you spoke of before?