Category: Net: Techy: PHP

I recently had to make a PHP class (let’s call it “class_A”) which returned an array of itself (to return multiple search results). All well and good and I used “$object=new self();” to do so like this:


class class_A {
public $setting;

public function doSomething() {
$toReturn=Array();
for ($i=1;$i<100;$i++) { $object=new self(); $object->setting=$i;
Array_push($toReturn,$object);
return $object;
}
}
Calling $class_A->doSomething() then returns 100 “class_A” objects.

However, I then needed to extend the PHP class (let’s call this class_B – declared with “class class_B extends class_A”) to take into account additional settings and I fully expected $object to be a new copy of class_B (as class B is technically the class being run).

Nope, it doesn’t work like that. I ended up with $object being class_A . I had to modify the code to change:
$object=new self();
to:
$object=clone $this;
which then allowed $class_B->doSomething(); to return 100 class_B objects.

Annoying, but something to remember!

Although I posted this on Stack Overflow, but I thought for reference purposes I’ll keep a copy here as well on how to extract the domain name from a URL in PHP:

If you just want to handle three character top level domains – then this code works:

<?php
// let's test the code works: these should all return
// example.com , example.net or example.org
$domains=Array('here.example.com',
'example.com',
'example.org',
'here.example.org',
'example.com/ignorethis',
'example.net/',
'http://here.example.org/longtest?string=here');
foreach ($domains as $domain) {
testdomain($domain);
}
function testdomain($url) {
if (preg_match('/^((.+)\.)?([A-Za-z][0-9A-Za-z\-]{1,63})\.([A-Za-z]{3})(\/.*)?$/',$url,$matches)) {
print 'Domain is: '.$matches[3].'.'.$matches[4].'
'."\n";
} else {
print 'Domain not found in '.$url.'
'."\n";
}
}
?>

$matches[1]/$matches[2] will contain any subdomain and/or protocol, $matches[3] contains the domain name, $matches[4] the top level domain and $matches[5] contains any other URL path information.

To match most common top level domains you could try changing it to:

if (preg_match('/^((.+)\.)?([A-Za-z][0-9A-Za-z\-]{1,63})\.([A-Za-z]{2,6})(\/.*)?$/',$url,$matches)) {

Or to get it coping with everything:

if (preg_match('/^((.+)\.)?([A-Za-z][0-9A-Za-z\-]{1,63})\.(co\.uk|me\.uk|org\.uk|com|org|net|int|eu)(\/.*)?$/',$url,$matches)) {

etc etc. If you want a list of top level domains, you may find Mozilla’s TLD List useful and DKIM Reputation Detected Registered Domains code handy.

I’ve just added a bit more security on to the system I’m working on and for that, I needed to check what the Content-type of the content the browser was sending (as I’m looking at checking that it’s an “application/x-amf” content type requested via Flash). Since I’m using Zend_Framework and wanted to make the check in the controller, it seemed sensible to use:
if (!($this->getRequest()->getHeader('Content-type')=='application/x-amf')) {
throw new Exception('Not a valid request');
}
which worked ok in Firefox. However, when testing in Internet Explorer, I always got “Not a valid request”… Why? Well, IE sends a “Content-Type” header instead of “Content-type”: note the different capitalisation!

It gets worse! Google Chrome (based on Apple WebKit), sends “content-type”.

Here’s the summary

Browser	Content type field	Content length field
Google Chrome 2.0.172.33	content-type	Content-Length
Firefox 3.0.11	Content-type	Content-Length
Microsoft Internet Explorer 8.0	Content-Type	Content-Length
Safari 4.0	Content-Type	Content-Length

Hope it helps somebody else!