Real World Xml Web Services: For Vb and Vb .Net Developers (DevelopMentor) [Paperback]

Chapter 5 talks about the Microsoft SOAP Toolkit. It's the less useful for me, but maybe for those wanting to publish COM components as Web Services this chapter is a must.

In chapter 6 the author explains you the basics of creating web services with .NET and the advantages of creating them with ASP.NET. Useful topics such as data caching, distributed transactions, namespaces and parameter encoding are covered in a very straight-to-the-point manner. I loved this chapter, in spite that it's not very long. Chapter 7 follows, explaining how to use SOAP headers in your web service and your clients. There you'll learn how to easily extend your web service's calls with custom SOAP headers -which can be used to pass custom information between the client and the server. Very useful examples in VB.NET.

In chapter 8 the author explains how to implement interfaces in web services -even, how to implement more than one interface by a single web service. I've found this chapter to be a very interesting one, since I come from the COM world and I really wanted this feature of implementing multiple interfaces to be available in web services. I didn't know I could do this -although I had already tried to "patch" it with my own implementation.

Chapter 9 is worth the price of the entire book. After all, it talks about the main application of web services in practice: passing data between the client and the server. It explains how to pass DataSets, XML documents and object arrays, among other things.

In chapter 10 SOAP extensions are covered in depth. Authorization using SOAP extensions is explained there. This is a VERY useful chapter. On the other hand, chapter 11 covers UDDI. Great chapters, both of them! From chapter 11 I liked the topic "Publishing Your Web Services with UDDI" a lot.

Chapter 12 goes into some details about interoperating with other SOAP toolkits, including some issues you may find. If you intend to make a web service written in .NET easily callable from any client (Java client, or whatever), this chapter is a must.

Chapter 13 explains the steps for creating a web service, from design to implementation issues. It's a tad short, in my opinion. For example, topics such as Usage Accounting are barely covered.

Appenix B adds some useful information, including tips and tricks for .NET developers, and traps you should avoid when developing a web service.

The entire book is a must-have in your developer's bookshelf. It touches everything respect to web services, and I guess that this will be my preferred book on the topic for long time. Five stars, yes!

The book is REALLY HARD TO READ, we are talking as dry as the sphinx's arm pit. The CD rom that comes with it contains the examples, however these are a mish-mash of VB6 and some .Net neither of which run easily. The .Net versions require updating in Visual Studio and can have some odd results. Some examples are even written with the server component in VB6 and the client in .Net - confusing to say the least.

If you want to learn how to practically implement a Web Service using VB then you should NOT look at this book. Most of the first 4 chapters are all about XML schemas and what they mean - with no "Real World" examples of how to create them in VB just the code of the schemas already created.

And another thing there is a large chunk of information about a "Real World" authentication and encryption implementation, however and I quote "I recommend that you use off-the shelf security implementations" - The author wouldn't even use this code! Microsoft has a Web services extension designed for authentication which the author doesn't mention anywhere.

Very disappointment to have spent good dollars on this book. I will be trying desperately to get my money back from Amazon.

As a DevelopMentor branded book, Yasser's tome seemed as good a place as any to start learning about web services and I'm happy to say that it doesn't disappoint. Even though I'm a C# fan and his examples are exclusively in VB .NET or VB6, the text is easy to follow and packed with useful information and tips obviously gained from lengthy immersion in the subject.

Chapter 1 is a quick introduction to the web service base platform, the standards it comprises, how they've been derived and how to write your first web service. It concludes with a short piece on when and when not to use web services. Essentially just an introduction to topics that are covered in the rest of the book, it's a quick 101 on the subject.

Chapters 2 to 4 look in greater depth at three of the standards that make up the base platform - XSD, SOAP and WSDL. At 160 pages for the three topics, they are unsurprisingly covered in great detail and in a clear manner that leaves you with only thoughts of what to write first instead of the questions the chapters haven't answered. Sometimes the answers are in between the lines for you to figure out yourself but they are there.

With the base technologies out of the way, Chapters 5 and 6 demonstrate its two 'web service toolkits', the SOAP Toolkit for COM developer and the .asmx functionaltity that's part of ASP.NET. The COM chapter is particularly good, working through both high and low-level APIs in some detail but without forgetting that it's introducing readers to something new and assuming prior knowledge.

Chapters 7 to 9 build on the platform built in chapter 6, teaching us how .NET allows us to work with SOAP Headers and Faults, and how to move data around with web services using ADO .NET. These two subjects are separated by a look at how we can use a WSDL document and the wsdl tool in .NET as a start point to create both an abstract service implementation and service proxies for our clients.

Again these are good chapters, especially the one on ADO.NET, but the other two seemed a little isolated. SOAP Headers are vital to the growth of web services and SOAP Faults are necessary for exception handling, but the discussion seemed to exist in its own small chapter simply because it didn't fit anywhere else. Why not expand the discussion to include or at least give a hint as to the headers that will be standardized soon. Likewise, in a chapter which talks about interface generation from a WSDL document, why not also mention the automatic generation of classes from the schema inside the WSDL file? A missed opportunity, but not one that really detracted from the chapter as a whole.

Finally in Chapter 10, we learn how to extend the .NET web service platform using SOAP Extensions. This is the most challenging chapter of the book, but again it's explained well and Yasser provides some really good examples here to illustrate every point he makes.

UDDI is the topic for Chapter 11. Like chapters 2 to 4, this chapter looks at the surface of UDDI (what it is, typical usage scenarios, how to publish service info to a UDDI server), but quickly heads underneath to work through its main data structures and demonstrate how to use the UDDI API. This chapter was the biggest eye-opener for me, although the level of its discourse fluctuated throughout which sometimes annoyed.

Last but one, Chapter 12 looks very practically at the key to web service - interoperability - by taking a few of the other SOAP Toolkits available today (COM, Java, DHTML) and trying to create clients on the .NET services already created in the book. There's a neat discussion for each kit, noting any difficulties that might be encountered when working cross-kits, although quite naturally there's only a taster here on this subject rather than a full exposé which would take another book.

Finally, Chapter 13 is a case study demonstrating the web service specific tools in Visual Studio .NET and the application of some of the concepts made plain in the rest of the book. The service is .NET and submitted to UDDI while the client is built in VB6. This was a nice wrap up to the book and a good way to finish up the other pieces of the puzzles (tools, procedures, code, etc) that hadn't been explained so far.

Overall, this is a very good book for .NET developers, for COM developers less so. The material is strong throughout and with only a few editorial quibbles and the overlarge body text font that irk, it's well worth the money and a recommended buy for web service developers, new and experienced. Even C# developers will get a lot out of it and the examples are reasonably simple to translate.