Price comparison calculator

[gsvavarsson]

hi, i'm new PHP, so I need your help.

I modified a calculator to my conditions but I want the result to overwrite the input boxes and submit btn.

 

here is the code:

 

ps. don't mind the Danish, i don't

<?php 

$page = $_GET['page']; 

class calc { 
     var $number1; 
     var $number2; 

          function add($number1,$number2) 
          { 
                   $result =$number1-($number2*0.98); 
                    echo("Du kommer til med ad spare $result dkk<br>"); 
                    exit; 
           } 
} 
$calc = new calc(); 
?> 
<TITLE>PHP Calculator v1</TITLE> 
<form name="calc" action="?page=calc" method="POST"> 
Nuværende månedlig udgift: <input type=text name=value1><br> 
Forbrug af kopper/md.: <input typ e=text name=value2><br> 
<input type=submit value="Calculate"> 
</form> 
<?php 
if($page == "calc"){ 
$number1 = $_POST['value1']; 
$number2 = $_POST['value2']; 
$oper = $_POST['oper']; 
     if(!$number1){ 
          echo("Du skal tast ind nuværende måndlig udgift!"); 
          exit; 
     } 
     if(!$number2){ 
          echo("Du skal tast ind Forbrug p/md.!"); 
          exit; 
     } 
     /*if(!$oper){ 
          echo("You must select an operation to do with the numbers!"); 
          exit; 
     } */
     if(!eregi("[0-9]", $number1)){ 
          echo("De skal være nummer!"); 
          exit; 
     } 
     if(!eregi("[0-9]", $number2)){ 
          echo("De skal være nummers!"); 
          exit; 
     } 
 if($number2<299) {
	 echo("Månedlig forbrug skal være 300 eller mere");
 }
     else{ 
          $calc->add($number1,$number2); 
     } 
} 
?>

 

mvh

[thomasw_lrd]

The way I've been handling this is to actually put html in  a function, and call that function to return the html with the new values.  There might be a better way.

 

switch ($action){
	case 'step1':
		echo page_update_form($result);
		break;

function page_update_form($result){
global $config;

$ret.='
<form>
<table>


</table>
</form>';
return $ret;
}

[gsvavarsson]

thanks but right now i still don't quite understand.

could you explain it a bit further?

 

best regards

[Psycho]

In my opinion, the structure of your page really needs a makeover. You have a class that does nothing but a simple calculation. You then have a lot of error handling outside the class. If that is all your class is going to do, I wouldn't even use a class. But, you could move the validations into the class to make it more useful. Also, your error handling is not very elegant since it uses exit(). Instead you should always display a complete page.

 

Also, your class defines two properties for the class - but never uses them. The variables you use in the add() method are not the same as the properties you defined for the class.

 

I have made some major modifications below. I think it is all correct - but since the code has no comments and the output is not english I'm not entirely sure.

 

<?php 

class calc
{
    var $number1 = ''; 
    var $number2 = '';
    var $errors = array();
    var $response = '';

    function add($value1, $value2) 
    {
        $this->set_number1($value1);
        $this->set_number2($value2);

        if(count($this->errors))
        {
            $this->response  = "The following errors occured:\n";
            $this->response .= "<ul>\n";
            foreach($this->errors as $error)
            {
                $this->response .= "<li>{$error}</li>\n";
            }
            $this->response .= "</ul>\n";
            return false;
        }
        else
        {
            $result = $this->number1 - ($this->number2*0.98);
            $this->response ="Du kommer til med ad spare $result dkk<br>";
            return true;
        }
    }

    function set_number1($value)
    {
        $this->number1 = trim($value);
        if(empty($this->number1))
        {
            $this->errors[] = "Du skal tast ind nuværende måndlig udgift!"; 
        }
        elseif(!ctype_digit($this->number1))
        {
            $this->errors[] = "De skal være nummer!";
        }
        return;
    }

    function set_number2($value)
    {
        $this->number2 = trim($value);
        if(empty($this->number2))
        {
            $this->errors[] = "Du skal tast ind Forbrug p/md.!"; 
        }
        elseif(!ctype_digit($this->number2))
        {
            $this->errors[] = "De skal være nummer!";
        }
        elseif($this->number2>299)
        {
            $this->errors[] = "Månedlig forbrug skal være 300 eller mere";
        }
        return;
    }
} 

$calc = new calc();
if(isset($_POST['value1']) && isset($_POST['value2']))
{ 
    $calc->add(($_POST['value1'], $_POST['value2']);
}

?>
<html>
<head>
<title>PHP Calculator v1</title>
</head>

<body>
<form name="calc" action="" method="post"> 
    Nuværende månedlig udgift: <input type=text name="value1" value="<?php echo $calc->number1; ?>"><br> 
    Forbrug af kopper/md.: <input type=text name="value2" value="<?php echo $calc->number2; ?>"><br> 
    <input type=submit value="Calculate"><br><br>
    <?php echo $calc->response; ?>
</form> 
</body>
</html>