Igor Wiedler has a recent post to his site about creating stateless services, specifically in the context of using a dependency injection container to manage the objects your application uses.

As more frameworks and libraries, particularly in the PHP world, move towards adopting the Dependency Injection pattern they are all faced with the problem of bootstrapping their application and constructing the object graph. In many cases this is solved by a Dependency Injection Container (DIC). Such a container manages the creation of all the things. The things it manages are services. Or are they?

He notes that, according to some of the principles of domain-driven design, "services" should be stateless - the results of calls to the service shouldn't alter it, it should only depend on the values passed in. He goes on to put this into the context of a DIC and gives an example of the "request service" (and how it violates the DDD principles of statelessness). He talks some about scopes (dependencies) and mutable services. He talks about methods to get around these issues with the "request" instance, ultimately coming to the conclusion that event listeners might be the way to go.

In his recent post Gonzalo Ayuso shows how to use Symfony to work with Windows services on the server.

Sometimes I need to stop/start remote Windows services with PHP. It's quite easy to do it with net commnand. This command is a tool for administration of Samba and remote CIFS servers. [...] Today we are going to create a PHP wrapper for [net rpc service].

He uses Behat to create a feature (test) file, the code behind the features and a service class that handles the actual work of interacting with the service (with methods to do things like stop, start and list running services). Examples of its use are also included.

On PHPMaster.com today there's a new article from Alejandro Gervasio introducing you to the concept of "services", a layer put on top of your models to make a common API that's easier to reuse.

Don't let the definition freak you out, as if you've been using MVC for a while the chances are you've used a service already. Controllers are often called services, as they carry out application logic and additionally are capable of interfacing to several client layers, namely views. Of course in a more demanding environment, plain controllers fail short in handling several clients without the aforementioned duplicating, so that's why the construction of a standalone layer is more suitable in such cases.

He explains the process behind creating a simple domain model (image here) and shows how the Service layer wraps it up into a simpler interface, leaving the model to handle the business logic. He uses the example of an "EncoderInterface" that's implemented in a "JsonEncoder" and "Serializer" to both provide a "setData" method.

On his blog today Jakub Zalas has posted a tutorial he's written up about using dependency injection in PHP with the Symfony2 dependency injection component (DIC).

Symfony's DependencyInjection component is a PHP implementation of a Service Container, or as others like to call it, a Dependency Injection Container (DIC). The component also provides useful tools for handling service definitions, like XML loaders or dumpers. If you want to learn more about the dependency injection or the dependency injection container, read an excellent series of articles on the subject by Fabien Potencier: What is Dependency Injection?

He walks you through the entire process - installing the needed libraries (the DIC, a config and class loader component and Buzz, a lightweight HTTP client). Code is included to show object creation the "usual way" and then creating the same types of objects in a dependency injection environment. Also included is a sample XML document describing the services for the container. He finishes the post with a GraphvizDumper-generated image for the container.

Brian Swan has a new post to his MSDN blog today that looks at working with the SQL Server Reporting Services SDK and PHP to automatically create some reports based on the date in your database.

In this post I'll dive into the SSRS SDK for PHP that was recently released by the Interoperability team here at Microsoft. [...] The documentation in the SDK is complete with explanations for the classes that make up the SDK, code examples, and a "hello world" example. However, in this post, I'll build a simple web page (code attached to this post) that renders the Sales report that I created last week.

He starts off with an overview of how all of the technology will fit together and some of the things you'll need to have before you can get started - a user with the right permissions and a connection to the server. The "SSRSReport" class in the SDK gives you quick access to load a report based on a named location. You can then use methods like "RenderAsHTML" to output it as HTML or one of other methods (like CSV, text, PDF, etc).

On the RIA Zone (a part of the DZone network) there's a new tutorial from Ryan Stewart about combining PHP with the Flash Collaboration Services (real-time collaboration and social capabilities via the LCCS) in the second part of his series (part one).

Another great way to integrate LCCS and PHP is with the REST APIs and the library that ships with the LCCS SDK. With those APIs we can perform a number of management functions including creating and deleting rooms, managing roles, and creating templates. These APIs make it very easy to create a customized, dynamic collaboration experience with PHP. You can create rooms on the fly for your users and get information about what kind of content is in those rooms. In this example we're going to create a basic room manager with PHP that will let us create, delete, and view information about specific rooms.

Code is included to use the AFCS PHP library to connect to the Services API and pass in the username and password directly from the user. The request is made and a token is passed back to the calling script. The XML description of the full Flex application is included in the tutorial.

From the phpblog on the IBM developerWorks website today, there's a quick new tutorial focusing on the use of the Service Component Architecture functionality in PHP to interface with the web service API that eBay offers.

I've just made the first code drop to support calling eBay Web services using the Service Component Architecture. Anyone who's tried calling the eBay soap APIs will know there are quite a few hoops to jump through to get it working. [...] The SCA eBay soap support hides this complexity by allowing you to specify the information as configuration parameters and then it makes sure the right things are placed in the header or the URL.

A code example is included that makes a connection to the web service, calls the GetSearchResults action for the query of "ipod" and, upon getting the results back, loops through them to display them to the page.

Despite opinions from some of the PHP community, interoperability between PHP applications isn't is such a bad state - at least According to Aaron Wormus:

The fact of the matter is that it's not such a big deal. Porting a plugin from Wordpress to Serendipity is usually trivial, and as we see more web-services based plugins (stuff like the awesome askimet) the task becomes simpler and simpler.

Interoperability is overrated, the more you think of it the more complex it gets. As you start throwing in new factors into the equation (how will this interoperate with a java/c# application) you start to develop monsters like JSR 170 which solve a lot of problems on paper, but in reality are too unwieldy to be truly useful.

He even lists out some of his "steps to interoperability" to help speed things along (like "use as much abstract code as possible" and "use services").

In his latest blog post, Adam Trachtenberg looks into the world of web services and comes out with three topics - SOAP, axis2, and SDO. He chooses to focus, though, on the last of these after working with it to really get a feel for what it can do.

n my role as eBay Platform Evangelist, I spend a lot of time exploring different XML technologies. SOAP is obviously the big one. No, it's not PEAR::SOAP or NuSOAP; it's axis2.

He talks a bit about what axis2 is and the need it fills in the web services world. He also talks about how it's been developed (not copied after SOAP, but more of a fresh start that happens to do the same things). After this quick look at axis2, though, he gets into the head of the post - SDO.

The other PHP XML extension I've been hearing a lot about is SDO. SDO is an attempt to provide a standard data interface regardless of the backend datasource. So, for example, you can interact with XML data in the exact same manner as information pulled from your database.

Adam decided to give it a try and see how it interacted with the eBay API with some simple code examples. The first of which looks through eBay Motors and finds the title and mileage for each of the items grabbed. It worked well, and didn't require too much more development than the SOAP predecesor, but there were a few quirks that made things a bit more difficult (like SDO's inability to completely consume a WSDL file and understand a SOAP service's functionality).

On the Zend Developer Zone, Cal Evans talks about one of the presenters of the upcoming Zend/PHP Conference and Expo - Ben Ramsey. He asked Ben some questions about the conference and a talk that he'll be giving - "XML & Web Services with PHP (An Overview)".

Ben Ramsey will be speaking on "XML & Web Services with PHP (An Overview)" at the upcoming Zend/PHPConference and Expo. Since I hang out with Ben in the freenode.net #phpc channel I thought it would be cool to talk to him for a bit about his session.

They talk about why Ben is passionate about web services, the two popular protocols for using these services - SOAP and REST, and which one of them Ben prefers.