Applied XML Programming for Microsoft .NET.pdf - Csbdu.in

Table 3-1: Key Properties of the XmlValidatingReader ClassPropertySchemaTypeValidationTypeXmlResolverDescriptioncollection of preloaded XDRs and XSDs. Schemapreloading is a trick used to speed up the validationprocess. Schemas, in fact, are cached, and there is noneed to load them every time.Gets the schema object that represents the currentnode in the underlying reader. This property is relevantonly for XSD validation. The object describes whetherthe type of the node is one of the built-in XSD types ora user-defined simple or complex type.Indicates the type of validation to perform. Feasiblevalues come from the ValidationType enumeration:Auto, None, DTD, XDR, and Schema.Sets the XmlResolver object used for resolving externalDTD and schema location references. TheXmlResolver is also used to handle any import orinclude elements found in XSD schemas.The validating reader uses the underlying reader to move around the document andimplements most of its XmlReader-derived properties by simply mirroring thecorresponding properties of the worker reader.XmlValidatingReader MethodsTable 3-2 lists the methods exposed by the XmlValidatingReader class that are eithernew or whose behavior significantly differs from the corresponding methods of theXmlReader class.Table 3-2: Public Methods of the XmlValidatingReader ClassMethodReadReadTypedValueSkipDescriptionThe underlying reader moves to the next node. At thesame time, the validating reader gets the nodeinformation and validates it using the schemainformation and the previously cached information.Gets the value for the underlying node as a commonlanguage runtime (CLR) type. The mapping can takeplace only for XSDs. Whenever a direct mapping is notpossible, the node value is returned as a string.Skips the children of the current node in the underlyingreader. You can't skip over badly formed XML text,however. In the XmlValidatingReader class, the Skipmethod also validates the skipped content.As you can see, the programming interface of the XmlValidatingReader class does notexplicitly provide a single method that can validate the entire contents of a document.The validating reader works incrementally, node by node, as the underlying readerdoes. Each validation error found along the way results in a particular event notificationbeing returned to the caller application. The application is then responsible for definingan ad hoc event handler and behaving as needed.64