help needed with simple PHP form!

[jennyp]

I'm trying to make a simple form. The user selects from a number of form elements (drop-down menus, etc), clicks send, whereupon the form is validated (ie, checking that certain selections aren't left out), and a page is then created summarising the user's choices, along with a shopping cart "buy now" button.

This was the way I started it on a document "choice.php":

Using drop-down menus, there's a number of name/value pairs, including a default "Select..."

<select name="selectFirstChoice" size="1">
<option selected value="unselected">Select...</option>
<option value="ChoiceA">Choice A</option>
<option value="ChoiceB">Choice B</option>
</select>

<select name="selectSecondChoice" size="1">
<option selected value="unselected">Select...</option>
<option value="ChoiceC">Choice C</option>
<option value="ChoiceD">Choice D</option>
</select>

The form's 'action' is "process.php", which firstly gets the posted variables:

$FirstChoice = $_GET['selectFirstChoice'];
$SecondChoice = $_GET['selectSecondChoice'];

My first question: Should I use POST or GET? I know many sites have all the variables in query strings, but doesn't this mean people could (theoretically at least) mess up the string and cause headaches for the page processing (shop cart etc)?

Anyway - then "process.php" goes on to do some validation (check for unselected options) by comparing against the default "unselected" option of the form:

if (($FirstChoice == 'unselected') || ($SecondChoice == 'unselected'))
{
echo '<br><br>You missed out a selection<br><br>Go <a href="choice.php">back</a>';
}

else
// here comes the page...
{
echo 'Here's the HTML with '.$FirstChoice.' and '.$SecondChoice.'.';
echo '<br>(A a bunch of other stuff...)';
}

(I'm going to put in some js client-side validation here also, but at the moment I'm trying to work out about the general form method, and how I can work server-side validation into it.)

My second question: When a user is returned to "choice.php" by a link on the "process.php" page, all the drop-down menu settings are lost (very annoying!). (It's OK if the browser's 'back' button is used, but not when using a link.) What methods can I use to get over this?

My third question: can I keep all this on one PHP page, which checks if the variables have meaningful contents and then displays the form? Can this include the validation?

I realise the 3 questions are probably inter-related, but I'd be glad of any comments and help!!

[eriksmoen]

1. It's all in the address bar 😛 normally, you'd use post with bigger text (more than 255 chars "textarea") or for more secure "password". One thing to remember, however is that POST doesn't like the back button. For something small and insensitive like select option boxes, just use GET.

2. to avoid issues, try....

   
   if(isset($_GET['selectFirstChoice']) && isset($_GET['selectSecondChoice']))
   { 
        $array1 = array('choiceA','choiceB','choiceC');
        $array2 = array('choiceZ','choiceY','choiceX');
   
    echo "<select name='selectFirstChoice'>";
    foreach($array1 as $key => $value)
    {
         $selected = ($_GET['value1'] == $value)? "selected" : "";
         echo "<option value='$value' $selected>$value</option>";
    }
    echo "</select>";
   
    echo "<select name='selectSecondChoice'>";
    foreach($array2 as $key => $value)
    {
         $selected = ($_GET['value2'] == $value)? "selected" : "";
         echo "<option value='$value' $selected>$value</option>";
    }
    echo "</select>";
   }
   

   3. using isset is good for keeping it on one page.

       
      
      if(isset($_GET['value1']) && isset($_GET['value2'])){ ... }
      else{ ... }
      

[jennyp]

Whoops - yes - always the string in the address bar! :o Thank you - except I'm getting "Parse error: parse error, unexpected T_STRING in blah/blah/blah/trial.php on line 33" ..line 33 being the "if(isset" line ...?

[eriksmoen]

cut and paste all the code in here. make sure to put the [ PHP ][ /PHP ] tags around it so it's easier to read.

[jennyp]

Sorry! My mistake! The code had bad linebreaks! :o BBEdit cleaned it up! Thanks for your fantastic help! 🙂 (I'm struggling!)

[eriksmoen]

awesome. no problem.

[jennyp]

But how to work that into my "if (($FirstChoice == 'unselected')" error-checking stuff...? :queasy:

[100110]

Hi jennyp, try this

if (($FirstChoice == '') || ($SecondChoice == ''))
{
echo '<br><br>You missed out a selection<br><br>Go <a href="choice.php">back</a>';
}

if there is no value then echo
Cheers

[jennyp]

Thanks.. but now I've got to weave that into eriksmoen's code... (I am definitely feeling queasy :queasy: )

[jennyp]

It's not working.. not capturing the form variables as set.. I think I have to start from the ground up again.. A drop-down form which (a) on submit checks for bad entries (ie blank or a certain string), & (b) if all OK on submit grabs the variables and writes code that uses those variables.. I must be tired.. 🙁

[eriksmoen]

if(isset($_GET['selectFirstChoice']) && isset($_GET['selectSecondChoice']))
{ 
  if($_GET['selectFirstChoice'] != 'unselected' && $_GET['selectSecondChoice'] != 'unselected')
  {
     $array1 = array('choiceA','choiceB','choiceC');
     $array2 = array('choiceZ','choiceY','choiceX');

 echo "<select name='selectFirstChoice'>";
 foreach($array1 as $key => $value)
 {
      $selected = ($_GET['value1'] == $value)? "selected" : "";
      echo "<option value='$value' $selected>$value</option>";
 }
 echo "</select>";

 echo "<select name='selectSecondChoice'>";
 foreach($array2 as $key => $value)
 {
      $selected = ($_GET['value2'] == $value)? "selected" : "";
      echo "<option value='$value' $selected>$value</option>";
 }
 echo "</select>";
  }
  else
  {
     echo "Please <a href='javascript:history.go(-1)'>Go Back</a> And Try Another Selection";
  }
}  

[jennyp]

I'd like to start from the ground up with this, if anyone has the patience! I need a drop-down form, which checks for blank/null values (or preferably values set to "unselected"), and which then summarises the selected variables and their values, prior to using them for other things. I want to avoid javascript completely. So, I wonder if I've got the flow of the code right like this: three 'blocks' of code, all on the same page:

// 1: if no variables are yet set - display form in 'original' untouched appearance

// 2: validation: if some variables are set, but one or more has the value "unselected" (or is empty) - display the form, with the selected value(s) showing, & ask for empty value(s)

// 3: if ALL variables are set and no values are missing - summarise the selections (as a basis for doing other things with them)

Does this look like the right logical flow? If so, am I right in thinking all 3 'code blocks' can be on the same php page?

[jennyp]

So far I have 'block 1' of the code I need (I think :rolleyes: ):

//grabs the current URL as variable
if(!empty($_SERVER['HTTPS'])) $page = "https://"; else $page = "http://www.";
$page .= $_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];

// if no variables are yet set - display form in 'original' appearance (form action is same page)
if(!isset($_GET['selectFirstChoice']) || !isset($_GET['selectSecondChoice']))
{
echo '<br>Seeing Code Block One<br>
<form action="'.$page.'" method="get" name="ChoiceForm">
Select choice 1:<br><select name="selectFirstChoice">
<option selected value="unselected">Select...</option>
<option value="choiceA">choiceA</option>
<option value="choiceB">choiceB</option>
<option value="choiceC">choiceC</option></select><br>
Select choice 2:<br><select name="selectSecondChoice">
<option selected value="unselected">Select...</option>
<option value="choiceX">choiceX</option>
<option value="choiceY">choiceY</option>
<option value="choiceZ">choiceZ</option></select><br>
<input type="submit" name="submitChoiceButton" value="Go">
</form><br>';
}

Now I need to make 'code block 2', ie, if some variables are set, but some have the value "unselected" - display the form with selections intact and ask for the empty values... like your code eriksmoen? (if I'm going in the right direction, that is :o )

[jennyp]

Well, what about this, which works... but I bet there's things wrong with it...

<?php
$HTMLHeaderToBody = '<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"><html><head><meta http-equiv="content-type" content="text/html;charset=iso-8859-1"><title>Jennys PHP Form</title></head><body>';

$HTMLFooterFromBody = '</body></html>';

//grabs the current URL as variable
if(!empty($_SERVER['HTTPS'])) $page = "https://"; else $page = "http://www."; $page .= $_SERVER['SERVER_NAME'].$_SERVER['REQUEST_URI'];

// if no variables are yet set - display form in 'original' appearance (form action is this page)

if(!isset($_GET['selectFirstChoice']) && !isset($_GET['selectSecondChoice'])) 
{
echo $HTMLHeaderToBody.'<br><form action="'.$page.'" method="get" name="ChoiceForm">Choice One:<br><br><select name="selectFirstChoice"><option selected value="unselected">Select...</option><option value="choiceA">choiceA</option><option value="choiceB">choiceB</option><option value="choiceC">choiceC</option></select><br><br>Choice Two:<br><br><select name="selectSecondChoice"><option selected value="unselected">Select...</option><option value="choiceX">choiceX</option><option value="choiceY">choiceY</option><option value="choiceZ">choiceZ</option></select><br><br><input type="submit" name="submitChoiceButton" value="Go!"></form><br><br>'.$HTMLFooterFromBody;
}

// if some variables are set but some have the value "unselected" - display the form AS ENTERED & ask for empty values (form action is this page)
if(isset($_GET['selectFirstChoice']) || isset($_GET['selectSecondChoice']))
{

$valuesChoice1 = array('unselected','choiceA','choiceB','choiceC');
$valuesChoice2 = array('unselected','choiceX','choiceY','choiceZ');

 if(($_GET['selectFirstChoice'] == 'unselected') || ($_GET['selectSecondChoice'] == 'unselected'))
	{
	echo $HTMLHeaderToBody;
	echo '<font color="red">You missed a selection.</font><br><br>';

// ...first choice
echo '<form action="'.$page.'" method="get" name="ChoiceForm">Choice One:<br><br><select name="selectFirstChoice">';

for($x = 0; $x < count($valuesChoice1); $x++) 
{ 
       // write "selected" if the value matches the one posted 
       if($valuesChoice1[$x] == $_GET['selectFirstChoice']) 
       { 
           $selected = ' selected'; 
        }else{ 
           $selected = ''; 
        } 
        // print the option 
        echo ' 
   <option value="'.$valuesChoice1[$x].'"'.$selected.'>'.$valuesChoice1[$x].'</option>'; 
} 

echo '</select>';

//...second choice
echo '<br><br>Choice Two:<br><br><select name="selectSecondChoice">';

for($x = 0; $x < count($valuesChoice2); $x++) 
{ 
       // write "selected" if the value matches the one posted 
       if($valuesChoice2[$x] == $_GET['selectSecondChoice']) 
       { 
           $selected = ' selected'; 
        }else{ 
           $selected = ''; 
        } 
        // print the option 
        echo ' 
   <option value="'.$valuesChoice2[$x].'"'.$selected.'>'.$valuesChoice2[$x].'</option>'; 
} 

echo '</select>';

echo '<br><br><input type="submit" name="submitChoiceButton" value="Go!"></form>';

echo $HTMLFooterFromBody;
}

}

// or - if all variables are set and no values are missing - summarise them
if(isset($_GET['selectFirstChoice']) && isset($_GET['selectSecondChoice']))
{
if(($_GET['selectFirstChoice'] !== 'unselected') && ($_GET['selectSecondChoice'] !== 'unselected'))
	{
echo 'All selections were made.<br>';
echo '<br><br>For Choice One you chose: '.$_GET['selectFirstChoice'].'<br>';
echo '<br><br>For Choice Two you chose: '.$_GET['selectSecondChoice'].'<br>';
	}
}

?>