Robust, sticky form demo with field validation

String Handling in PHP example from a Well House Consultants training course
More on String Handling in PHP [link]

This example is described in the following article(s):
• Painting a masterpiece in PHP - [link]

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Source code: myform.php Module: H107


<?php

/* This is an example that shows you how you can define
your form and all the various elements in an array and
then use common code to check that entries have been made
in each and validate them.  This is just a template for
you to work from but is VERY easily extensible */

# The following could be read from a file or database

# You could add in fields for input type, individual error
# messages, etc

$form = array(
array( "hidden",        "current",      'aax15'),
array( "First Name",    "fname",        '^[A-Z][a-z]+'),
array(  "Surname",      "sname",        '^[A-Z][a-z]+'),
array(  "Sex",          "gender",       '^[mfMF]$'),
array(  "Age",          "age",          '^\d{1,3}$'),
array(  "Email Addy",   "email",        '^\S+@\S+$'));

# For a live application, put the functions in an include file

function makeform($source) {
        global $explain;
        $html = "";
        foreach ($source as $row) {
           if ($row[0] == "hidden") {
                $html .=
                        "<input type = hidden name=$row[1] ".
                        "value = \"$row[2]\">";
           } else {
                $cook = htmlspecialchars(stripslashes(
                        $_REQUEST[$row[1]]));
                if ($explain[$row[1]]) {
                $html .= "<font color=red>".
                        $explain[$row[1]]."</font><br>";
                        }
                $html .= $row[0] .
                        "<input name=$row[1] ".
                        "value = \"$cook\">";
                $html .= "<br>";
           }
        }
        $html .= "<input type=submit>";
        return $html;
        }

function validateform($against) {
        $errsofar = "";
        foreach ($against as $row) {
           if ($row[0] != "hidden") {
                $errsofar .= chek($row);
                }
        }
        return $errsofar;
        }

function chek($row) {
        global $explain;
        $matches =
                preg_match("/$row[2]/",$_REQUEST[$row[1]]);
        if ($matches) return "Y";
        $explain[$row[1]] = "You got this one wrong:";
        return "N";
        }

$explain = array();
$needform = 1;
if ($_REQUEST[current] == "aax15") {
        $mainhtml = "Please correct me<br>";
        $errcode = validateform($form);
        if (! ereg("N",$errcode)) $needform = 0;
} else {
        $mainhtml = "";
}

if ($needform == 1) {
        $mainhtml .= "<form>".makeform($form)."</form>";
} else {
        $mainhtml = "Well Done!";
        # Business logic to go here
}
?>
<html>
<head><title>Parametrised for fillment </title></head>
<body bgcolor=#FFFFDE><h1>A form to Phil</h1>
<?= $mainhtml ?><hr>
Copyright etc <?= $errcode ?>
</body></html>

Learn about this subject

This module and example are covered on the following public courses:
* Learning to program in PHP
* PHP Programming
* Beginning PHP - weekend course / hobby / club / leisure users
* PHP Programming
* Learning to program in PHP
Also available on on site courses for larger groups

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Other Examples

This example comes from our "String Handling in PHP" training module. You'll find a description of the topic and some other closely related examples on the "String Handling in PHP" module index page.

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