I admit, sometimes I get language envy. Don’t get me wrong, I love php, but every once in a while I’ll hear about a feature in another language that just gets me going. The C# Reflection implementation, IntelliSense and LINQ immediately come to mind. I really want to get a look at these features and play with them but, alas, I just haven’t yet. (Honestly, I’m just not that good at C# yet. Soon though, very soon.)

BTW, yes I know php has Reflection but, the way I understand it, the .NET Reflection implementation kicks the crap out of the php one. Get over it.

Now it looks like there’s a quasi-sorta-kinda implementation of LINQ done in PHP with the totally original title of PHPLinq. It’s not a true port of LINQ, being that it deals with strings and isn’t done at the language level, but it’s still pretty compelling in it’s own right.

If you don’t know what LINQ is all about it stands for Language Integrated Query and is a set of extensions to the .NET Framework that encompass language-integrated query, set, and transform operations. It extends C# and Visual Basic with native language syntax for queries and provides class libraries to take advantage of these capabilities.

That basically means it allows you to query stuff, similar in concept but different in practice to how you would query a database. PHPLinq works well for searching an array of objects using a SQL like 0bject syntax.

There’s a great tutorial on Switch on the Code that goes into some detail on how to use PHPLinq with a good example of usage. To help pique your interest the below should give you a reason to check it out; the code below searches an array for all the strings in an array with a string length less than 5 characters:

<?php
// Create data source
$names = array("John", "Peter", "Joe", "Patrick", "Donald", "Eric");
$result = from('$name')->in($names)
            ->where('$name => strlen($name) < 5')
            ->select('$name'); 
 
print_r($result);
?>

Notice how it’s laid out like a database abstraction? Pretty cool, right?

The really exciting part about PHPLinq is that it can work off of lots of data sources like XML, RSS and a database table (more on this in a minute). Here’s an example taken from the unit tests for PHPLinq:

<?php
$rssFeed = simplexml_load_string(file_get_contents('http://blog.maartenballiauw.be/syndication.axd'));
$result = from('$item')->in($rssFeed->xpath('//channel/item'))
			->orderByDescending('$item => strtotime((string)$item->pubDate)')
			->take(2)
			->select('new {
							"PostTitle" => (string)$item->title,
							"PostAuthor" => (string)$item->author,
							"MetaData" => new {
												"Url" => (string)$item->link,
												"Guid" => (string)$item->guid,
												"PostDate" => strtotime((string)$item->pubDate)
										  }
					  }');
 
print_r($result);
?>

The above will return only the post title, author and whatever meta data the feed contains.

When I think about the database option I get a headache though; I can’t, for the life of me, think of when I would want to use PHPLinq to search a return database call. If I understand right the flow would work as a) grab all database rows and b) use PHPLinq to search through those rows.

This idea goes against everything I’ve ever known about SQL and resource management. It’s sacrilegious to grab all the rows in a table and just plain silly to use a separate layer of the program to parse those results. What possible argument could there be for not using plain old SQL (or even a SQL generator) and just let MySQL do the heavy lifting.

Admittedly, I haven’t found any code samples for how the SQL portion would work so I may be way off base here.

Either way, PHPLinq is still a compelling module to help sifting through array sets and XML. It should make searching files a lot easier too. Even if that’s not enough PHPLinq is still worth checking out if for no other reason an example of an interesting idea done in php.