XML Fed Form Interface
This is a demonstration of how you can use XML to feed PHP to generate a form. It is helpful when a flexible form interface is needed. This example includes the name of the field, the length, a regex validation string, default value, label for the input, whether it is required or not, and error text. It could be extended have multilingual validation and error text.
<?xml version="1.0" encoding="utf-8" ?>
<interface>
<name>Works</name>
<fields>
<field>
<name>URL</name>
<length>255</length>
<validation>[\w\.\-]{2,255}</validation>
<default>domain.com</default>
<label>URL</label>
<value>url.com</value>
<required>true</required>
<errortext>Letters, numbers, periods and dashes only</errortext>
</field>
<field>
<name>id</name>
<length>11</length>
<validation>[\d]{1,11}</validation>
<default>1</default>
<label>Id</label>
<required>true</required>
<errortext>Ids must be all digits</errortext>
</field>
</fields>
</interface>
This is the PHP that reads the XML. It uses SimpleXML, which is really nice.
<?php echo '<?xml version="1.0" encoding="utf-8" ?>' ?>
<?php
$xml=file_get_contents('bw.xml');
$xmldata = new SimpleXMLElement($xml);
$bValid=true;
/* Validate the submitted data */
if (isset($_POST['submit']))
{
$bValid=true;
foreach ($xmldata->fields->field as $f)
if (isset($_POST["{$f->name}"]))
{
$f->value=$_POST["{$f->name}"];
if (!preg_match('/^'.$f->validation.'$/',$_POST["{$f->name}"]))
{
$f->invalid=(bool)true;
$bValid=false;
}
}
}
?>
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html lang="en-US" xml:lang="en-US" xmlns="http://www.w3.org/1999/xhtml">
<head>
<title>XML Form</title>
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
<style type="text/css">
label
{
font-weight:bolder;
}
input,label
{
display:block;
}
.invalid
{
color:#f00;
}
</style>
</head>
<body>
<h1>XML Form Sourcing Demo</h1>
<hr />
<h2>Generated Inputs</h2>
<!--
Generates the form from the XML data. Note the use of the invalid flag for highlighting, and the display of
errortext if appropriate.
-->
<form action="#" method="post">
<?php foreach ($xmldata->fields->field as $f) : ?>
<label <?php if (isset($f->invalid)) echo 'class="invalid"' ?> for="<?php echo $f->name?>"><?php echo (($f->required==
'true')?'*':'').$f->label ?>
<?php if (isset($f->invalid)) echo ' '.$f->errortext; ?>
<input name="<?php echo $f->name ?>" id="<?php echo $f->name ?>"
maxlength="<?php echo $f->length ?>"
value="<?php echo (isset($f->value)?$f->value:$f->default) ?>" />
</label>
<?php endforeach ?>
<br />
<input name="submit" type="submit" />
</form>
<h2>Raw XML Data</h2>
<!-- Display the raw XML data, for debugging/development -->
<blockquote><?php echo nl2br(htmlentities(file_get_contents('bw.xml'))) ?></blockquote>
<h2>Parsed XML</h2>
<!-- Display how SimpleXML parsed the XML, again for debugging/development -->
<?php
echo '<pre>';
var_dump($xmldata);
echo '</pre>';
?>
<h2>Updated XML (if valid)</h2>
<!-- Show how the XML was updated, if it was valid -->
<?php
if ($bValid)
echo '<pre>'.nl2br(htmlentities($xmldata->asXML())).'</pre>';
?>
</body>
</html>This is well-suited for applications which must use connection data into a variety of external interfaces. In this case, the data can be presented, entered, validated, and stored, then used later by a different process.
| Print article | This entry was posted by elvis on 03/05/11 at 07:09:50 am . Follow any responses to this post through RSS 2.0. |