Chris Garrett

Chapter 10 – Web Services

This chapter discusses Web Services, along with their related technologies, protocols, and standards, such as Simple Object Access Protocol (SOAP), Web Services Description Language (WSDL), Extensible Markup Language (XML), and the XML Schema Definition (XSD) standard. The chapter examines the role of Web Services and how messages are passed between servers and data sources. Simple Web Services as well as Web Services (consumers) using the .NET Framework were created and VS.NET Beta 2 to show how the Web Service messaging infrastructure works and how it can be used transparently to the developer. The power of Web Services is due to its foundation in nonproprietary protocols and standards. Web Services would not be as useful if it were not built on XML for defining data and structure, XSD for defining structure, SOAP for defining a messaging transport mechanism over the well-established HTTP, WSDL for defining method interfaces in XML, Universal Description, Discovery, and Integration, and DISCO, the Web Service discovery description document.

Chapter 13 – Creating a Message Board with ADO and XML

This chapter analyzes message board and creates a solution to fit with all the requirements. The message board is an Object-Oriented application that is scalable, maintainable, and well-defined. A built-in security model is made where every action that requires administrative access is checked before the requestor is allowed to perform the operation. User Interface (UI) is somewhat extensible as it dynamically applies styles to multiple types of Web Controls that are defined using Cascading Style Sheet (CSS) and an Extensible Markup Language (XML) document. Each Web Form created inherits the FormBase class that allows all Web Forms to have access to a few common methods and properties, in addition to the System.Web.UI.Page methods and properties. UI contains all the necessary interfaces to browse through boards, threads, and messages, as well as interfaces to administer users, and those that contain interfaces to create and delete Boards, threads, and Messages. Overall, the chapter presents a functioning message board that could be placed anywhere and run on top of SQL Server or MS Access.

Chapter 3 – ASP Server Controls

The purpose of this chapter is to discuss the ASP.NET Web Controls. These are placed in WebPages. Thus, we cannot isolate them and discuss them without knowing how the ASP.NET Engine works, and how it maintains the states of the server controls. Hence, the chapter presents brief overviews of various concepts like HTML Forms, server-side processing, and in-page coding vs. code-behind. A procedure is given to develop a simple ASP.NET project using VS.NET. The chapter also introduces a very promising technology named Custom User Control. The ASP.NETserver controls are here to stay. They provide exceptional functionalities and abilities to develop server-side codes just like the VB 6 codes that used to be developed in the old days. The bound controls make it easy and quick to develop powerful data-oriented applications on the. However, each of these controls has many properties and events beyond the materials presented in this chapter.

Chapter 4 – Configuring ASP.NET

The configuration capabilities provided by ASP.NET enable to configure almost every aspect of ASP.NET and the way applications are processed. It provides this ability using the machine.config file and web.config files. These files are processed in a hierarchical manner with each higher-level file overriding previous settings. All settings are cached, and when a change is detected in the configuration files, the configuration is then reached. When using the configuration files to configure ASP.NET, various tags, subtags, attributes, and options are used. Each of these enables to control built-in configuration options or create new configuration options as seems fit. By using the available options, one can control everything from application variables down to compilation options. The configuration files used by ASP.NETare formatted in XML and are case-sensitive. All values within configuration are accessible using one of the three methods of “Retrieving Settings” section: Session Method, ConfigurationSettings.App Settings, and ConfigurationSettings.GetConfig.

Chapter 8 – Using XML in the .NET Framework

The aim of this chapter is to introduce the basic concepts of XML. The chapter provides an overview of the .NET classes available to read, store, and manipulate XML documents. The examples presented in this chapter serve as good models for developing business applications using XML and ASP.NET. The .NETs System.Xml namespace contains probably the richest collection of XML-related classes available thus far in any other software development platform. The System.Xml namespace has been further enriched by the recent addition of XPathDocument and XPathNavigator classes. Since XML can be enhanced using a family of technologies, there are innumerable techniques a reader should judiciously learn from other sources to design, develop, and implement complex real-world applications.

Chapter 2 – ASP.NET Namespaces

Microsoft.VisualBasic is a Microsoft specific namespace that provides access to the VB.NET compiler and code generator. The System namespace provides all of the foundations for the other namespaces, including the various data types and the Array. One will be using the objects in this namespace quite a bit, and often without even realizing it. System.Collections provides the base classes for the other collection objects in the .NET Framework, as well as a few useful regular classes, such as the Hash Table and BitArray. System.Web is a very important namespace for ASP.NET. It contains all of the functionality required to communicate between client and server; in essence, it is the heart of ASP.NET. The HttpRequest and HttpResponse objects enable to examine data returned from client and send information back to the client. Web namespace are two very important subnamespaces: System.Web.UI.HtmlControls and System.Web.UI.WebControls.. These two namespaces provide all of the objects that are used to display user interfaces to the client browser. Without these, one cannot interact properly with users, if at all. System.Data is essentially ADO.NET. In this namespace, one will find all of the tools that are needed to communicate with any type of data that ADO.NET can access. These classes can even interact with XML. Finally, System.Xml enables to handle and manipulate XML data.

Chapter 7 – Introduction to ADO.NET: A Simple Address Book

Microsoft has put a lot effort into .NET, and it shows in the 2500-plus objects that they have provided in the .NET Framework. ADO.NET continues the tradition of ADO simplifying data access, while allowing for more flexible and powerful solutions than ever. Microsoft has added much power to ADO.NET, and provided clear ties to classic ADO that enable the veteran ADO programmer to easily move into the new environment. The chapter discusses the disconnected nature of the ADO.NET architecture and made great use of the DataReader object in Address Book example. The chapter also introduces to the Data Access Layer (DAL) concept, and created a sample application the used the DAL to insert data using Embedded SQL statements, and Stored procedures. System.Data.SqlTypes and the SqlDbTypes enumeration are used and discussed that they are related, but have very different uses, such as the System.Data.SqlTypes namespace provider objects that are used to create SQL Server-compatible variables in our code, and then use the SqlDbTypes enumeration to specify the data type of a Parameter object for a command.

Chapter 6 – Optimizing Caching Methods

High performance is one of the most important aspects of any Web application. With the use of ASP.NETs caching features, the performance of application can be dramatically increased. Any application can benefit from the use of the caching features; by using the correct types of caching in the correct locations, one can optimize these benefits. Output caching is used to cache entire pages. It is accessed either through the @ OutputCache directive or programmatically through the HttpCachePolicy cache. By setting the duration option, one can control the length of time that page is stored in the cache. The additional features provided by the use of the VaryByParam, VaryByHeader, and VaryByCustom parameters enable to control the various versions of the pages that are stored in the cache. Data caching is the lowest level of caching available and enables to cache data at the object level. Three methods are used to call the data caching functions. The first is the cache method, which is used in the same method that one would use a dictionary. There are no additional options available when using data caching with this method. The second and third methods are cache.add and cache.insert. The syntax and usage of these two methods are identical, and the difference between the two is that cache.add returns an object. Accessing data caching by using the cache.add and cache.insert methods provides with several options to control the cached data. The first option is the specification of files, directories, and other cache keys that the cached object is dependent upon. The second option is the use of two methods to specify the length of time that the object is stored in the cache. The third is the setting of priority levels for cached data.

Chapter 9 – Debugging ASP.NET

Error handling is an important aspect of software development. Good robust applications anticipate various errors and take an active role in resolving them without crashing the program. The chapter discusses two distinctive methods of error handling—structured and unstructured. While the unstructured error handling mechanism continues to be supported in .NET, it is recommended that programmers make the switch to the structured error handling mechanism using the Try-Catch-Finally statement. Besides handling errors, the new tracing capability found in .NET makes the life of a programmer much easier. No longer do you have to insert Response. Removing the Trace statements during deployment is simply a matter of setting an attribute. Finally, Visual Studio .NET allows you to set breakpoints in your application so that the flow of variables and codes can be examined during runtime.

Chapter 12 – Creating an ADO.NET Shopping Cart

An application has been developed that enables customers to browse a catalog of books by category or range, add selections to a virtual shopping cart, remove items from the cart and simulate processing an order by logging in and submitting updates to the order table in the database. The power of Extensible Markup Language (XML) has been leveraged and its ability to represent data and structure, Web Services and their methods explored, databases designed and procedures stored, custom code behind classes in C# developed and a multitude of uses covered for ADO.NET. The chapter also explores database design and implementation, creating two databases for the application, one for Access and one for SQL. The chapter covers entities and their attributes and how both work with each other to create a normalized database. Lastly, a set of stored procedures has been developed that handles all data interaction with the database, preventing the use of “ad hoc” queries against the database.