One page application - design and human interface MATTERS

this example from a Well House Consultants training course
More on this [link]

This example is described in the following article(s):
• Not just a PHP program - a good web application - [link]

If you're searching for a page where you can try this code, select here

This example references the following resources:
http://www.wellho.net/pix/lhs9_

Source code: p_fifth.php Module: H050


<?php

/*
1. Code should be commented for programmer
2. Page should include instructions for the user
3. Forms should include a submit button, even if they
   only have a single input box which submits on "enter"
4. Code should echo user inputs
5. First page should not perform submission actions on nothing
6. Fields should usually be sticky
7. Data should be validated
8. Data should be secure against injection attacks
9. Common code should be grouped into functions
10. Generated HTML should conform to selected standard (XHTML?)
11. Program and design elements should be separated
12. Error messages should be good 'uns
*/

// -----------------------  Standard constants  -------------

$copyyear = date("Y");
$company = "Well House Consultants";

// -----------------------  Standard functions  -------------

function inputbox($prompt,$boxname) {
        return ("<tr><td>".htmlspecialchars($prompt).
        "</td><td><input name=\"$boxname\" value=\"".
        htmlspecialchars(stripslashes($_REQUEST[$boxname])).
        "\" /></td></tr>");
        }
function hidden($boxname,$value) {
        return
        "<input type=\"hidden\" name=\"$boxname\" value=\"$value\">" ;
        }

function submit() {
        return ("<tr><td>&nbsp;</td><td><input type=\"submit\" /></td></tr>");
        }

function checknumber($field,$msg,$lower = 0, $upper = 0) {
        global $grumble;
        $good = 1 ;
        if ($_REQUEST[$field] <= $lower and
                $lower >= $upper) $good = 0;
        if ($_REQUEST[$field] >= $upper and
                $lower < $upper) $good = 0;
        if (! is_numeric($_REQUEST[$field])) $good = 0;
        if ($good == 0) $grumble .= "* <font color=\"red\">".
                        " <b>$msg</b></font><br />";
        return $good;
        }

function cook($in) {
        return (htmlspecialchars(stripslashes($in))); }

// -----------------------  Business logic  -----------

function calctonnage () {
        $tons = $_REQUEST[height] * $_REQUEST[width] *
                $_REQUEST[depth] * $_REQUEST[density];
        return $tons;
        }

// -----------------------  Main code ----------------

$ok = 1;
$grumble = "";
$llimg = "c";

if ($_REQUEST[userid] == "777") {
        $ok *= checknumber("height",
                "Height must be positive", 0);
        $ok *= checknumber("width",
                "Width must be positive", 0);
        $ok *= checknumber("depth",
                "Depth must be positive", 0);
        $ok *= checknumber("density",
                "Density must be positive", 0);
        if ($ok == 1) {

                $tonnage = calctonnage();

                $saying = "That is good data input ....<br />";
                $saying .= "<br />A Box ".cook($_REQUEST[height]).
                        " by ".cook($_REQUEST[width]).
                        " by ".cook($_REQUEST[depth]).
                        " density of  ".cook($_REQUEST[density]).
                        "<br /><b>has a weight of $tonnage</b><br /><br />";
                $llimg = floor($tonnage) % 10;

        } else {
                $saying = "<b><u>Please review these errors:</u></b>".
                "<br />$grumble";
        }
} else {
        $saying = "Please complete the form<br />";
}

// -----------------------  Look and feel  ----------------
?>
<html>
<head>
<title>Simple PHP Form Demonstration</title>
<style type="text/css">
<!--
.title {
        font-family: Arial, Helvetica, sans-serif;
        font-size: 24px;
        font-weight: bold;
        color: #883300;
        color: #441100;
        text-align: center;
}
.introline {
        font-family: Arial, Helvetica, sans-serif;
        font-size: 18px;
        font-style: normal;
        font-weight: 800;
        color: #883300;
        color: #441100;
        text-align: center;
}
.nonitaltext {
        font-family: Arial, Helvetica, sans-serif;
        font-size: 14px;
        font-style: normal;
        color: #000000;
}
.ctext {
        font-family: Arial, Helvetica, sans-serif;
        font-size: 14px;
        font-style: normal;
        text-align: center;
        color: #000000;
}
.error {
        font-family: "Times New Roman", Times, serif;
        color: #FF0000;
        text-align: center;
}
-->
</style>
</head>
<body>
<center><table width="640" bgcolor="#FFEEDD" cellpadding="15"><tr>
<td colspan="2" valign="top">
<div class="title">Calculate the weight of a cube</div></td>
<tr><td><div class="nonitaltext">
<?= $saying ?><br>
<table class="nonitaltext"><form method="POST">
<?= inputbox("How tall","height") ?>
<?= inputbox("How Wide","width") ?>
<?= inputbox("How Deep","depth") ?>
<?= inputbox("Density","density") ?>
<?= hidden("userid","777") ?>
<?= submit() ?>
</form></table></div>
</td><td valign="top"><div class="ctext">
<img src="http://www.wellho.net/pix/lhs9_<?= $llimg ?>.jpg"
hspace="5"><br clear=all>
A demonstration page from a PHP course</div></td></tr>
<tr><td colspan="2"><div class="introline">
Copyright <?= $company ?>, <?= $copyyear ?>
</div></td></tr></table>
</center>
</body>
</html>

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