Interface IXMLReader

Interface for an XML filter.

Namespace: Sax

Assembly: Lucene.Net.Benchmark.dll

Syntax

public interface IXMLReader

Remarks

This module, both source code and documentation, is in the Public Domain, and comes with NO WARRANTY. Seehttp://www.saxproject.org for further information.

An XML filter is like an XML reader, except that it obtains its events from another XML reader rather than a primary source like an XML document or database.Filters can modify a stream of events as they pass on to the final application.

The IXMLFilter helper class provides a convenient base for creating SAX2 filters, by passing on all IEntityResolver, IDTDHandler, IContentHandler and IErrorHandler events automatically.

Properties

ContentHandler

Gets or Sets a content event handler.

Declaration

IContentHandler ContentHandler { get; set; }

Property Value

Type	Description
IContentHandler

Remarks

If the application does not register a content handler, all content events reported by the SAX parser will be silently ignored.

Applications may register a new or different handler in the middle of a parse, and the SAX parser must begin using the new handler immediately.

DTDHandler

Gets or Sets a DTD event handler.

Declaration

IDTDHandler DTDHandler { get; set; }

Property Value

Type	Description
IDTDHandler

Remarks

If the application does not register a DTD handler, all DTD events reported by the SAX parser will be silently ignored.

Applications may register a new or different handler in the middle of a parse, and the SAX parser must begin using the new handler immediately.

EntityResolver

Gets or Sets an entity resolver.

Declaration

IEntityResolver EntityResolver { get; set; }

Property Value

Type	Description
IEntityResolver

Remarks

If the application does not register an entity resolver, the IXMLReader will perform its own default resolution.

Applications may register a new or different resolver in the middle of a parse, and the SAX parser must begin using the new resolver immediately.

ErrorHandler

Gets or Sets an error event handler.

Declaration

IErrorHandler ErrorHandler { get; set; }

Property Value

Type	Description
IErrorHandler

Remarks

If the application does not register an error handler, all error events reported by the SAX parser will be silently ignored; however, normal processing may not continue. It is highly recommended that all SAX applications implement an error handler to avoid unexpected bugs.

Applications may register a new or different handler in the middle of a parse, and the SAX parser must begin using the new handler immediately.

Methods

GetFeature(String)

Look up the value of a feature flag.

Declaration

bool GetFeature(string name)

Parameters

Type	Name	Description
System.String	name	The feature name, which is a fully-qualified URI.

Returns

Type	Description
System.Boolean	The current value of the feature (true or false).

Remarks

The feature name is any fully-qualified URI. It is possible for an XMLReader to recognize a feature name but temporarily be unable to return its value. Some feature values may be available only in specific contexts, such as before, during, or after a parse. Also, some feature values may not be programmatically accessible. (In the case of an adapter for SAX1 {@link Parser}, there is no implementation-independent way to expose whether the underlying parser is performing validation, expanding external entities, and so forth.)

All XMLReaders are required to recognize the http://xml.org/sax/features/namespaces and the http://xml.org/sax/features/namespace-prefixes feature names.

Typical usage is something like this:

XMLReader r = new MySAXDriver();
                        // try to activate validation
try {
   r.SetFeature("http://xml.org/sax/features/validation", true);
} catch (SAXException e) {
   Console.Error.WriteLine("Cannot activate validation."); 
}
                        // register event handlers
r.ContentHandler = new MyContentHandler();
r.ErrorHandler = new MyErrorHandler();
                        // parse the first document
try {
   r.Parse("http://www.foo.com/mydoc.xml");
} catch (IOException e) {
   Console.Error.WriteLine("I/O exception reading XML document");
} catch (SAXException e) {
   Console.Error.WriteLine("XML exception reading document.");
}

Implementors are free (and encouraged) to invent their own features, using names built on their own URIs.

Exceptions

Type	Condition
SAXNotRecognizedException	If the feature value can't be assigned or retrieved.
SAXNotSupportedException	When the IXMLReader recognizes the feature name but cannot determine its value at this time.

See Also

SetFeature(String, Boolean)

GetProperty(String)

Look up the value of a property.

Declaration

object GetProperty(string name)

Parameters

Type	Name	Description
System.String	name	The property name, which is a fully-qualified URI.

Returns

Type	Description
System.Object	The current value of the property.

Remarks

The property name is any fully-qualified URI. It is possible for an XMLReader to recognize a property name but temporarily be unable to return its value. Some property values may be available only in specific contexts, such as before, during, or after a parse.

IXMLReaders are not required to recognize any specific property names, though an initial core set is documented for SAX2.

Implementors are free (and encouraged) to invent their own properties, using names built on their own URIs.

Exceptions

Type	Condition
SAXNotRecognizedException	If the property value can't be assigned or retrieved.
SAXNotSupportedException	When the IXMLReader recognizes the property name but cannot determine its value at this time.

See Also

SetProperty(String, Object)

Parse(InputSource)

Parse an XML document.

Declaration

void Parse(InputSource input)

Parameters

Type	Name	Description
InputSource	input	The input source for the top-level of the XML document.

Remarks

The application can use this method to instruct the XML reader to begin parsing an XML document from any valid input source (a character stream, a byte stream, or a URI).

Applications may not invoke this method while a parse is in progress (they should create a new XMLReader instead for each nested XML document). Once a parse is complete, an application may reuse the same XMLReader object, possibly with a different input source. Configuration of the IXMLReader object (such as handler bindings and values established for feature flags and properties) is unchanged by completion of a parse, unless the definition of that aspect of the configuration explicitly specifies other behavior. (For example, feature flags or properties exposing characteristics of the document being parsed.)

During the parse, the XMLReader will provide information about the XML document through the registered event handlers.

This method is synchronous: it will not return until parsing has ended. If a client application wants to terminate parsing early, it should throw an exception.

Exceptions

Type	Condition
SAXException	Any SAX exception, possibly wrapping another exception.
System.IO.IOException	An IO exception from the parser, possibly from a byte stream or character stream supplied by the application.

See Also

InputSource

Parse(String)

EntityResolver

DTDHandler

ContentHandler

ErrorHandler

Parse(String)

Parse an XML document from a system identifier (URI).

Declaration

void Parse(string systemId)

Parameters

Type	Name	Description
System.String	systemId	The system identifier (URI).

Remarks

This method is a shortcut for the common case of reading a document from a system identifier. It is the exact equivalent of the following:

Parse(new InputSource(systemId));

If the system identifier is a URL, it must be fully resolved by the application before it is passed to the parser.

Exceptions

Type	Condition
SAXException	Any SAX exception, possibly wrapping another exception.
System.IO.IOException	An IO exception from the parser, possibly from a byte stream or character stream supplied by the application.

SetFeature(String, Boolean)

Set the value of a feature flag.

The feature name is any fully-qualified URI. It is possible for an XMLReader to expose a feature value but to be unable to change the current value. Some feature values may be immutable or mutable only in specific contexts, such as before, during, or after a parse.

All XMLReaders are required to support setting http://xml.org/sax/features/namespaces to true and http://xml.org/sax/features/namespace-prefixes to false.

Declaration

void SetFeature(string name, bool value)

Parameters

Type	Name	Description
System.String	name	The feature name, which is a fully-qualified URI.
System.Boolean	value	The requested value of the feature (true or false).

Exceptions

Type	Condition
SAXNotRecognizedException	If the feature value can't be assigned or retrieved.
SAXNotSupportedException	When the IXMLReader recognizes the feature name but cannot set the requested value.

See Also

GetFeature(String)

SetProperty(String, Object)

Set the value of a property.

Declaration

void SetProperty(string name, object value)

Parameters

Type	Name	Description
System.String	name	The property name, which is a fully-qualified URI.
System.Object	value	The requested value for the property.

Remarks

The property name is any fully-qualified URI. It is possible for an IXMLReader to recognize a property name but to be unable to change the current value. Some property values may be immutable or mutable only in specific contexts, such as before, during, or after a parse.

IXMLReaders are not required to recognize setting any specific property names, though a core set is defined by SAX2.

This method is also the standard mechanism for setting extended handlers.

Exceptions

Type	Condition
SAXNotRecognizedException	If the property value can't be assigned or retrieved.
SAXNotSupportedException	When the IXMLReader recognizes the property name but cannot set the requested value.

See Also

XMLFilter