The significant abstract classes that provide an extensible model are the Xml Reader, the Xml Writer, and the XPath Navigator.
It was a goal to provide a seamless experience when moving between XML and relational data. Extensibility: This was achieved through the use of abstract classes to define the XML API and the ability to be able to plug together these classes.
NET Framework Version V2.0 release (formerly referred to as "Visual Studio codename Whidbey"). Usability enhancements: These enhancements make common tasks even easier to do in less lines of code, with support for a greater range of features to broaden the reach and capability of the applications.
Within this roadmap is an overview of the data access support in ADO. Querying Data Sources: This is standards support for the W3C XQuery language for querying XML, with the ability to aggregate data from different data sources such as SQL Server databases and local XML files.
For example, the following code is used to create an Xml Reader that performs validation and strips insignificant whitespace from the document at the same time. The code example below shows how to indent both elements and attributes on new lines.
Xml Reader Settings settings = new Xml Reader Settings(); settings. A key scenario for the settings classes is that they can be reused to create multiple Xml Readers and Xml Writers, potentially to multiple threads, for example, when used in the pages in an ASP.
Mark Fussell, Lead Program Manager Microsoft Corporation March 2004 Summary: This first in a series of articles by Mark Fussell details the improvements to the XML APIs in System. (32 printed pages) Introduction Design Goals for System. Xml Version 2.0 Top Ten Features 10) Static Creation Methods on Xml Reader and Xml Writer 9) XML Standards Support by Default 8) Universal Type Support and Conversion 7) Xml Reader and Xml Writer Usability 6) The XQuery Language 5) Security 4) Easier XPath Queries with Namespaces 3) The XPath Document as a Better DOM 2) XPath Editable Navigator, an Updatable Cursor 1) Performance Conclusion The Microsoft Developer Tools Roadmap 2003-2005 describes the innovations and enhancements within the Visual Studio 2005 and . This series of articles provides an in-depth review of the forthcoming V2.0 release for the System. Some form of XML manipulation is inevitable in application development today, and all developers need to have an understanding of the core XML classes. XML is low in the processing stack and performance gains here have a ripple affect through the rest of the application.
It is important to note that the common data model supported by these classes is the XQuery 1.0 and XPath 2.0 Data Model, which although based upon the XML Infoset specification, extends it with XML Schema type information and the ability to support collections of documents and complex values, called sequences.Integrating schema information deeply across the System.Xml APIs not only provides support for type-aware query languages such as XQuery, but provides for more efficient storage, improved performance, and better integration with the . Based on these guiding design goals, the Webdata XML product team set about creating the best user experience for working with XML as a data access technology. Xml contained a wealth of innovation from the simple-to-use pull-model Xml Reader and push-model Xml Writer classes, to the industry-first cursor model API, the XPath Navigator, XML Schema validation, and a performant read-only XML store for XSLT based upon the XPath data model, the XPath Document. NET Framework is a set of XML classes that allow you to build XML support into your applications. The V1 design goals above continue to apply in driving the V2.0 release; however, further design goals were added in the V2.0 release around the requirements needed to build a strong set of XML components for the Win FX APIs. The latter is of particular significance since it combines a random access, cursor-style API with an XPath query engine.You can also set the Conformance Level to "Auto," meaning that it automatically attempts to either read the XML as a document or a fragment depending on the type of nodes encountered.The following code creates an Xml Reader that performs DTD validation and sets the conformance level to Auto. Dtd Validate = true; Xml Reader reader = Xml Reader. Read()) A conformance issue when using the Xml Text Writer was that it did not check the element and attribute name characters for invalid characters.Before we look at code examples using the new features, let's look at the XML document and schema that we will use throughout this article.The XML document is an example bookstore inventory.It is possible to layer settings onto an existing Xml Reader or Xml Writer class to provide additional functionality. Xsd Validate = true; Xml Reader reader = Xml Reader. Read()) This approach is additive in that functionality cannot be removed; thus, once an Xml Reader is created as a validating reader it cannot have that validation removed by layering a nonvalidating Xml Reader on top. Xsd Validate = true; // XML Schema Validation performed Xml Reader outerreader = Xml Reader.This "pipelining" approach allows you to chain together Xml Readers over Xml Readers or Xml Writers over Xml Writers. Select Single Node("//book"); Xml Node Reader nodereader = new Xml Node Reader(node); Xml Reader Settings settings = new Xml Reader Settings(); settings. For those of you who encountered the V1 constraint that XSD validation with the Xml Validating Reader class could only be performed on an Xml Text Reader class, you can sleep peacefully at last! Create(innerreader, settings); Support for XQuery as a strongly typed language has a pervasive effect across the System.